{
    "slug": "k-factor-bend-allowance",
    "title": "معامل K وبدل الانحناء لثني الصفائح المعدنية",
    "description": "معاملات K حسب المادة والسماكة للانحناء الحر والانحناء إلى القاع والسك وفق DIN 6935، مع أمثلة محلولة لبدل الانحناء وخصمه في انحناءات 90 درجة.",
    "lang": "ar",
    "tables": [
        {
            "caption": "معاملات K حسب المادة والسماكة وطريقة الانحناء (محسوبة وفق DIN 6935 + نطاقات منشورة)",
            "columns": [
                "المادة",
                "t (mm)",
                "قالب V (mm)",
                "R_i (mm)",
                "R/t",
                "K وفق DIN 6935",
                "K للانحناء الحر (DIN ↔ المنشور)",
                "K للانحناء إلى القاع",
                "K للسك",
                "y = K·t (mm)",
                "المصدر"
            ],
            "rows": [
                {
                    "المادة": "DC01 mild steel",
                    "t (mm)": "0.5",
                    "قالب V (mm)": "6",
                    "R_i (mm)": "0.96",
                    "R/t": "1.92",
                    "K وفق DIN 6935": "0.40",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.40–0.43",
                    "K للانحناء إلى القاع": "0.44–0.47",
                    "K للسك": "0.41–0.46",
                    "y = K·t (mm)": "0.20",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "DC01 mild steel",
                    "t (mm)": "0.8",
                    "قالب V (mm)": "6",
                    "R_i (mm)": "0.96",
                    "R/t": "1.20",
                    "K وفق DIN 6935": "0.34",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.34–0.43",
                    "K للانحناء إلى القاع": "0.44–0.47",
                    "K للسك": "0.41–0.46",
                    "y = K·t (mm)": "0.27",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "DC01 mild steel",
                    "t (mm)": "1.0",
                    "قالب V (mm)": "8",
                    "R_i (mm)": "1.28",
                    "R/t": "1.28",
                    "K وفق DIN 6935": "0.35",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.35–0.43",
                    "K للانحناء إلى القاع": "0.44–0.47",
                    "K للسك": "0.41–0.46",
                    "y = K·t (mm)": "0.35",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "DC01 mild steel",
                    "t (mm)": "1.5",
                    "قالب V (mm)": "12",
                    "R_i (mm)": "1.92",
                    "R/t": "1.28",
                    "K وفق DIN 6935": "0.35",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.35–0.43",
                    "K للانحناء إلى القاع": "0.44–0.47",
                    "K للسك": "0.41–0.46",
                    "y = K·t (mm)": "0.53",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "DC01 mild steel",
                    "t (mm)": "2.0",
                    "قالب V (mm)": "16",
                    "R_i (mm)": "2.56",
                    "R/t": "1.28",
                    "K وفق DIN 6935": "0.35",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.35–0.43",
                    "K للانحناء إلى القاع": "0.44–0.47",
                    "K للسك": "0.41–0.46",
                    "y = K·t (mm)": "0.70",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "DC01 mild steel",
                    "t (mm)": "3.0",
                    "قالب V (mm)": "25",
                    "R_i (mm)": "4.00",
                    "R/t": "1.33",
                    "K وفق DIN 6935": "0.36",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.36–0.43",
                    "K للانحناء إلى القاع": "0.44–0.47",
                    "K للسك": "0.41–0.46",
                    "y = K·t (mm)": "1.07",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "DC01 mild steel",
                    "t (mm)": "4.0",
                    "قالب V (mm)": "32",
                    "R_i (mm)": "5.12",
                    "R/t": "1.28",
                    "K وفق DIN 6935": "0.35",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.35–0.43",
                    "K للانحناء إلى القاع": "0.44–0.47",
                    "K للسك": "0.41–0.46",
                    "y = K·t (mm)": "1.40",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "DC01 mild steel",
                    "t (mm)": "6.0",
                    "قالب V (mm)": "50",
                    "R_i (mm)": "8.00",
                    "R/t": "1.33",
                    "K وفق DIN 6935": "0.36",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.36–0.43",
                    "K للانحناء إلى القاع": "0.44–0.47",
                    "K للسك": "0.41–0.46",
                    "y = K·t (mm)": "2.14",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "DX51D+Z galvanized",
                    "t (mm)": "0.8",
                    "قالب V (mm)": "6",
                    "R_i (mm)": "0.96",
                    "R/t": "1.20",
                    "K وفق DIN 6935": "0.34",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.34–0.43",
                    "K للانحناء إلى القاع": "0.44–0.47",
                    "K للسك": "0.41–0.46",
                    "y = K·t (mm)": "0.27",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "DX51D+Z galvanized",
                    "t (mm)": "1.5",
                    "قالب V (mm)": "12",
                    "R_i (mm)": "1.92",
                    "R/t": "1.28",
                    "K وفق DIN 6935": "0.35",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.35–0.43",
                    "K للانحناء إلى القاع": "0.44–0.47",
                    "K للسك": "0.41–0.46",
                    "y = K·t (mm)": "0.53",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "DX51D+Z galvanized",
                    "t (mm)": "3.0",
                    "قالب V (mm)": "25",
                    "R_i (mm)": "4.00",
                    "R/t": "1.33",
                    "K وفق DIN 6935": "0.36",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.36–0.43",
                    "K للانحناء إلى القاع": "0.44–0.47",
                    "K للسك": "0.41–0.46",
                    "y = K·t (mm)": "1.07",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "304 stainless",
                    "t (mm)": "0.8",
                    "قالب V (mm)": "8",
                    "R_i (mm)": "1.60",
                    "R/t": "2.00",
                    "K وفق DIN 6935": "0.40",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.40–0.45",
                    "K للانحناء إلى القاع": "0.46–0.48",
                    "K للسك": "0.44–0.47",
                    "y = K·t (mm)": "0.32",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "304 stainless",
                    "t (mm)": "1.5",
                    "قالب V (mm)": "16",
                    "R_i (mm)": "3.20",
                    "R/t": "2.13",
                    "K وفق DIN 6935": "0.41",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.41–0.45",
                    "K للانحناء إلى القاع": "0.46–0.48",
                    "K للسك": "0.44–0.47",
                    "y = K·t (mm)": "0.61",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "304 stainless",
                    "t (mm)": "3.0",
                    "قالب V (mm)": "32",
                    "R_i (mm)": "6.40",
                    "R/t": "2.13",
                    "K وفق DIN 6935": "0.41",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.41–0.45",
                    "K للانحناء إلى القاع": "0.46–0.48",
                    "K للسك": "0.44–0.47",
                    "y = K·t (mm)": "1.23",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "316L stainless",
                    "t (mm)": "1.0",
                    "قالب V (mm)": "10",
                    "R_i (mm)": "2.10",
                    "R/t": "2.10",
                    "K وفق DIN 6935": "0.41",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.41–0.45",
                    "K للانحناء إلى القاع": "0.46–0.48",
                    "K للسك": "0.44–0.47",
                    "y = K·t (mm)": "0.41",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "316L stainless",
                    "t (mm)": "2.0",
                    "قالب V (mm)": "20",
                    "R_i (mm)": "4.20",
                    "R/t": "2.10",
                    "K وفق DIN 6935": "0.41",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.41–0.45",
                    "K للانحناء إلى القاع": "0.46–0.48",
                    "K للسك": "0.44–0.47",
                    "y = K·t (mm)": "0.82",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "316L stainless",
                    "t (mm)": "3.0",
                    "قالب V (mm)": "32",
                    "R_i (mm)": "6.72",
                    "R/t": "2.24",
                    "K وفق DIN 6935": "0.41",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.41–0.45",
                    "K للانحناء إلى القاع": "0.46–0.48",
                    "K للسك": "0.44–0.47",
                    "y = K·t (mm)": "1.23",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "5052-H32 aluminium",
                    "t (mm)": "0.8",
                    "قالب V (mm)": "6",
                    "R_i (mm)": "0.96",
                    "R/t": "1.20",
                    "K وفق DIN 6935": "0.34",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.34–0.40",
                    "K للانحناء إلى القاع": "0.42–0.46",
                    "K للسك": "0.38–0.44",
                    "y = K·t (mm)": "0.27",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "5052-H32 aluminium",
                    "t (mm)": "1.5",
                    "قالب V (mm)": "12",
                    "R_i (mm)": "1.92",
                    "R/t": "1.28",
                    "K وفق DIN 6935": "0.35",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.35–0.40",
                    "K للانحناء إلى القاع": "0.42–0.46",
                    "K للسك": "0.38–0.44",
                    "y = K·t (mm)": "0.53",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "5052-H32 aluminium",
                    "t (mm)": "3.0",
                    "قالب V (mm)": "25",
                    "R_i (mm)": "4.00",
                    "R/t": "1.33",
                    "K وفق DIN 6935": "0.36",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.36–0.40",
                    "K للانحناء إلى القاع": "0.42–0.46",
                    "K للسك": "0.38–0.44",
                    "y = K·t (mm)": "1.07",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "6061-T6 aluminium *",
                    "t (mm)": "1.0",
                    "قالب V (mm)": "10",
                    "R_i (mm)": "1.80",
                    "R/t": "1.80",
                    "K وفق DIN 6935": "0.39",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.39–0.45",
                    "K للانحناء إلى القاع": "0.46–0.48",
                    "K للسك": "0.44–0.47",
                    "y = K·t (mm)": "0.39",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "6061-T6 aluminium *",
                    "t (mm)": "2.0",
                    "قالب V (mm)": "20",
                    "R_i (mm)": "3.60",
                    "R/t": "1.80",
                    "K وفق DIN 6935": "0.39",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.39–0.45",
                    "K للانحناء إلى القاع": "0.46–0.48",
                    "K للسك": "0.44–0.47",
                    "y = K·t (mm)": "0.78",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "6061-T6 aluminium *",
                    "t (mm)": "3.0",
                    "قالب V (mm)": "32",
                    "R_i (mm)": "5.76",
                    "R/t": "1.92",
                    "K وفق DIN 6935": "0.40",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.40–0.45",
                    "K للانحناء إلى القاع": "0.46–0.48",
                    "K للسك": "0.44–0.47",
                    "y = K·t (mm)": "1.20",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "C110 copper",
                    "t (mm)": "1.0",
                    "قالب V (mm)": "8",
                    "R_i (mm)": "1.28",
                    "R/t": "1.28",
                    "K وفق DIN 6935": "0.35",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.35–0.40",
                    "K للانحناء إلى القاع": "0.42–0.46",
                    "K للسك": "0.38–0.44",
                    "y = K·t (mm)": "0.35",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "C110 copper",
                    "t (mm)": "2.0",
                    "قالب V (mm)": "16",
                    "R_i (mm)": "2.56",
                    "R/t": "1.28",
                    "K وفق DIN 6935": "0.35",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.35–0.40",
                    "K للانحناء إلى القاع": "0.42–0.46",
                    "K للسك": "0.38–0.44",
                    "y = K·t (mm)": "0.70",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "C260 brass",
                    "t (mm)": "1.0",
                    "قالب V (mm)": "8",
                    "R_i (mm)": "1.28",
                    "R/t": "1.28",
                    "K وفق DIN 6935": "0.35",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.35–0.40",
                    "K للانحناء إلى القاع": "0.42–0.46",
                    "K للسك": "0.38–0.44",
                    "y = K·t (mm)": "0.35",
                    "المصدر": "S1/S2/S3"
                },
                {
                    "المادة": "C260 brass",
                    "t (mm)": "2.0",
                    "قالب V (mm)": "16",
                    "R_i (mm)": "2.56",
                    "R/t": "1.28",
                    "K وفق DIN 6935": "0.35",
                    "K للانحناء الحر (DIN ↔ المنشور)": "0.35–0.40",
                    "K للانحناء إلى القاع": "0.42–0.46",
                    "K للسك": "0.38–0.44",
                    "y = K·t (mm)": "0.70",
                    "المصدر": "S1/S2/S3"
                }
            ]
        },
        {
            "caption": "ما معامل K الذي ينبغي استخدامه لفولاذ طري بسماكة 2 mm في الانحناء الحر؟",
            "columns": [
                "الخطوة",
                "الكمية",
                "القيمة",
                "ملاحظة"
            ],
            "rows": [
                {
                    "الخطوة": "1",
                    "الكمية": "R/t",
                    "القيمة": "2.0 / 2.0 = 1.00",
                    "ملاحظة": "‏DIN 6935: k = 0.65 + 0.5·log10(1.00) = 0.65"
                },
                {
                    "الخطوة": "2",
                    "الكمية": "K = k/2",
                    "القيمة": "0.325",
                    "ملاحظة": "قيمة الجدول تُقرَّب إلى 0.33؛ وهذا المثال يحمل القيمة غير المقرَّبة"
                },
                {
                    "الخطوة": "3",
                    "الكمية": "BA = (π/180)·A·(R + K·t), A = 90°",
                    "القيمة": "4.163 mm",
                    "ملاحظة": "‏1.5708 × 2.65"
                },
                {
                    "الخطوة": "4",
                    "الكمية": "OSSB = (R + t)·tan(A/2)",
                    "القيمة": "4.000 mm",
                    "ملاحظة": "‏4.0 × tan 45°"
                },
                {
                    "الخطوة": "5",
                    "الكمية": "Flat legs from 50/30 outside",
                    "القيمة": "46.000 / 26.000 mm",
                    "ملاحظة": "‏A_flat = 50 − OSSB، B_flat = 30 − OSSB"
                },
                {
                    "الخطوة": "6",
                    "الكمية": "L = A + B + BA",
                    "القيمة": "76.16 mm",
                    "ملاحظة": "‏BD = 2×4.000 − 4.163 = 3.837؛ ‏50 + 30 − 3.837 = 76.163 ✓"
                },
                {
                    "الخطوة": "7",
                    "الكمية": "If CAD default K = 0.44",
                    "القيمة": "L = 76.52 mm (+0.361)",
                    "ملاحظة": "‏BA = 4.524 mm؛ أربعة انحناءات تتراكم نحو 1.4 mm"
                }
            ]
        },
        {
            "caption": "لماذا تعتمد برامج CAD قيمة افتراضية لمعامل K تساوي 0.44؟",
            "columns": [
                "الشرط",
                "أي معامل K",
                "القيمة النموذجية",
                "الخطوة التالية"
            ],
            "rows": [
                {
                    "الشرط": "Ductile mild steel, air bending, R/t 0.5–3",
                    "أي معامل K": "DIN 6935 Table / formula",
                    "القيمة النموذجية": "0.25–0.40",
                    "الخطوة التالية": "انحناء اختباري ثم استنتاج معامل K الحقيقي عكسيًا"
                },
                {
                    "الشرط": "Mild steel, CAD default, V = 6–8t",
                    "أي معامل K": "Published medium air (t–3t)",
                    "القيمة النموذجية": "0.43 (defaults 0.44–0.45)",
                    "الخطوة التالية": "استخدمه فقط عندما تتطابق العدة والمادة؛ وإلا فانتقل إلى DIN"
                },
                {
                    "الشرط": "304/316 stainless, air bending",
                    "أي معامل K": "DIN 6935 at R/t 2.0–2.2",
                    "القيمة النموذجية": "0.40–0.41 (316 shop data up to 0.50)",
                    "الخطوة التالية": "تحقّق من الارتداد المرن والتشقق وتآكل القالب"
                },
                {
                    "الشرط": "5052-H32 aluminium, air bending",
                    "أي معامل K": "DIN 6935 at R/t 1.2–1.3",
                    "القيمة النموذجية": "0.34–0.36",
                    "الخطوة التالية": "تحقّق من التشقق؛ والطبقة الطرية تأخذ الحد الأدنى"
                },
                {
                    "الشرط": "6061-T6 aluminium, air bending",
                    "أي معامل K": "Published hard air / DIN upper bound",
                    "القيمة النموذجية": "0.39–0.45",
                    "الخطوة التالية": "الانحناء الاختباري إلزامي؛ فـ T6 يتشقق — فضّل نصف قطر أكبر"
                },
                {
                    "الشرط": "C110 copper / C260 brass",
                    "أي معامل K": "DIN 6935 at R/t 1.28",
                    "القيمة النموذجية": "0.35",
                    "الخطوة التالية": "أكّد حالة التلدين؛ والطبقة الصلبة تأخذ الحد الأعلى"
                },
                {
                    "الشرط": "Bottoming",
                    "أي معامل K": "Published t–3t tier of the class",
                    "القيمة النموذجية": "0.42–0.48",
                    "الخطوة التالية": "لا تُعِد استخدام معامل K الخاص بالانحناء الحر أبدًا"
                },
                {
                    "الشرط": "Coining",
                    "أي معامل K": "Published t–3t tier of the class",
                    "القيمة النموذجية": "0.38–0.47",
                    "الخطوة التالية": "لاحظ أن السك يقع تحت الانحناء إلى القاع في الجدول المنشور (انظر سؤال السك مقابل القاع)"
                },
                {
                    "الشرط": "R/t > 5",
                    "أي معامل K": "K = 0.50",
                    "القيمة النموذجية": "0.50",
                    "الخطوة التالية": "المحور المحايد يعود إلى منتصف السماكة"
                },
                {
                    "الشرط": "R/t < 0.5",
                    "أي معامل K": "DIN Table low end",
                    "القيمة النموذجية": "0.15–0.25",
                    "الخطوة التالية": "خطر تشقق مرتفع — وسّع نصف القطر أو غيّر المادة"
                },
                {
                    "الشرط": "New material / new tooling / no data",
                    "أي معامل K": "Test bend, back-solve",
                    "القيمة النموذجية": "measured",
                    "الخطوة التالية": "ثبّت معامل K المقاس في مكتبة مواد CAD"
                }
            ]
        },
        {
            "caption": "كيف يتغير معامل K مع نصف القطر الداخلي؟",
            "columns": [
                "R/t",
                "k (DIN 6935)",
                "K = k/2",
                "y/t",
                "ملاحظة"
            ],
            "rows": [
                {
                    "R/t": "0.05",
                    "k (DIN 6935)": "0.00",
                    "K = k/2": "0.00",
                    "y/t": "0.00",
                    "ملاحظة": "المحور المحايد على السطح الداخلي؛ خطر تشقق — لا تصمّم عند هذه القيمة"
                },
                {
                    "R/t": "0.07",
                    "k (DIN 6935)": "0.06",
                    "K = k/2": "0.03",
                    "y/t": "0.03",
                    "ملاحظة": "قيمة من جدول مصدر؛ وصيغة DIN نفسها تعطي 0.07 (k) عند هذا الـ R/t — الوثيقة الأصلية متناقضة داخليًا هنا"
                },
                {
                    "R/t": "0.10",
                    "k (DIN 6935)": "0.15",
                    "K = k/2": "0.08",
                    "y/t": "0.08",
                    "ملاحظة": ""
                },
                {
                    "R/t": "0.20",
                    "k (DIN 6935)": "0.30",
                    "K = k/2": "0.15",
                    "y/t": "0.15",
                    "ملاحظة": ""
                },
                {
                    "R/t": "0.25",
                    "k (DIN 6935)": "0.35",
                    "K = k/2": "0.18",
                    "y/t": "0.18",
                    "ملاحظة": ""
                },
                {
                    "R/t": "0.33",
                    "k (DIN 6935)": "0.41",
                    "K = k/2": "0.21",
                    "y/t": "0.21",
                    "ملاحظة": ""
                },
                {
                    "R/t": "0.50",
                    "k (DIN 6935)": "0.50",
                    "K = k/2": "0.25",
                    "y/t": "0.25",
                    "ملاحظة": ""
                },
                {
                    "R/t": "0.75",
                    "k (DIN 6935)": "0.59",
                    "K = k/2": "0.30",
                    "y/t": "0.30",
                    "ملاحظة": ""
                },
                {
                    "R/t": "1.00",
                    "k (DIN 6935)": "0.65",
                    "K = k/2": "0.33",
                    "y/t": "0.33",
                    "ملاحظة": ""
                },
                {
                    "R/t": "1.25",
                    "k (DIN 6935)": "0.70",
                    "K = k/2": "0.35",
                    "y/t": "0.35",
                    "ملاحظة": ""
                },
                {
                    "R/t": "1.50",
                    "k (DIN 6935)": "0.74",
                    "K = k/2": "0.37",
                    "y/t": "0.37",
                    "ملاحظة": ""
                },
                {
                    "R/t": "1.75",
                    "k (DIN 6935)": "0.77",
                    "K = k/2": "0.39",
                    "y/t": "0.39",
                    "ملاحظة": ""
                },
                {
                    "R/t": "2.00",
                    "k (DIN 6935)": "0.80",
                    "K = k/2": "0.40",
                    "y/t": "0.40",
                    "ملاحظة": ""
                },
                {
                    "R/t": "2.50",
                    "k (DIN 6935)": "0.85",
                    "K = k/2": "0.43",
                    "y/t": "0.43",
                    "ملاحظة": ""
                },
                {
                    "R/t": "3.00",
                    "k (DIN 6935)": "0.89",
                    "K = k/2": "0.45",
                    "y/t": "0.45",
                    "ملاحظة": ""
                },
                {
                    "R/t": "3.50",
                    "k (DIN 6935)": "0.92",
                    "K = k/2": "0.46",
                    "y/t": "0.46",
                    "ملاحظة": ""
                },
                {
                    "R/t": "4.00",
                    "k (DIN 6935)": "0.95",
                    "K = k/2": "0.48",
                    "y/t": "0.48",
                    "ملاحظة": ""
                },
                {
                    "R/t": "4.50",
                    "k (DIN 6935)": "0.98",
                    "K = k/2": "0.49",
                    "y/t": "0.49",
                    "ملاحظة": ""
                },
                {
                    "R/t": "5.00",
                    "k (DIN 6935)": "1.00",
                    "K = k/2": "0.50",
                    "y/t": "0.50",
                    "ملاحظة": "R/t ≥ 5: المحور المحايد عند منتصف السماكة"
                }
            ]
        },
        {
            "caption": "ما الفرق بين الانحناء الحر والانحناء إلى القاع والسك من حيث معامل K؟",
            "columns": [
                "فئة المادة",
                "طريقة الانحناء",
                "R = 0–t",
                "R = t–3t",
                "R > 3t"
            ],
            "rows": [
                {
                    "فئة المادة": "Soft (aluminium 5052, copper, brass)",
                    "طريقة الانحناء": "Air bending",
                    "R = 0–t": "0.33",
                    "R = t–3t": "0.40",
                    "R > 3t": "0.50"
                },
                {
                    "فئة المادة": "Soft (aluminium 5052, copper, brass)",
                    "طريقة الانحناء": "Bottoming",
                    "R = 0–t": "0.42",
                    "R = t–3t": "0.46",
                    "R > 3t": "0.50"
                },
                {
                    "فئة المادة": "Soft (aluminium 5052, copper, brass)",
                    "طريقة الانحناء": "Coining",
                    "R = 0–t": "0.38",
                    "R = t–3t": "0.44",
                    "R > 3t": "0.50"
                },
                {
                    "فئة المادة": "Medium (mild steel, galvanized)",
                    "طريقة الانحناء": "Air bending",
                    "R = 0–t": "0.38",
                    "R = t–3t": "0.43",
                    "R > 3t": "0.50"
                },
                {
                    "فئة المادة": "Medium (mild steel, galvanized)",
                    "طريقة الانحناء": "Bottoming",
                    "R = 0–t": "0.44",
                    "R = t–3t": "0.47",
                    "R > 3t": "0.50"
                },
                {
                    "فئة المادة": "Medium (mild steel, galvanized)",
                    "طريقة الانحناء": "Coining",
                    "R = 0–t": "0.41",
                    "R = t–3t": "0.46",
                    "R > 3t": "0.50"
                },
                {
                    "فئة المادة": "Hard (304/316 stainless)",
                    "طريقة الانحناء": "Air bending",
                    "R = 0–t": "0.40",
                    "R = t–3t": "0.45",
                    "R > 3t": "0.50"
                },
                {
                    "فئة المادة": "Hard (304/316 stainless)",
                    "طريقة الانحناء": "Bottoming",
                    "R = 0–t": "0.46",
                    "R = t–3t": "0.48",
                    "R > 3t": "0.50"
                },
                {
                    "فئة المادة": "Hard (304/316 stainless)",
                    "طريقة الانحناء": "Coining",
                    "R = 0–t": "0.44",
                    "R = t–3t": "0.47",
                    "R > 3t": "0.50"
                }
            ]
        },
        {
            "caption": "كيف أحسب بدل الانحناء؟",
            "columns": [
                "الحد",
                "الصيغة",
                "كيف تقرأه"
            ],
            "rows": [
                {
                    "الحد": "K factor",
                    "الصيغة": "K = y / t, 0 ≤ K ≤ 0.5",
                    "كيف تقرأه": "إزاحة المحور المحايد عن السطح الداخلي نسبةً إلى السماكة"
                },
                {
                    "الحد": "Neutral radius",
                    "الصيغة": "R_neutral = R_i + K × t",
                    "كيف تقرأه": "نصف قطر القوس الذي يحتفظ بطوله فعلًا"
                },
                {
                    "الحد": "Bend allowance BA",
                    "الصيغة": "BA = (π/180) × A × (R_i + K × t)",
                    "كيف تقرأه": "طول قوس المحور المحايد عبر الانحناء"
                },
                {
                    "الحد": "Outside setback OSSB",
                    "الصيغة": "OSSB = (R_i + t) × tan(A/2)",
                    "كيف تقرأه": "طول المماس من القمة إلى نقطتي تماس الانحناء"
                },
                {
                    "الحد": "Bend deduction BD",
                    "الصيغة": "BD = 2 × OSSB − BA",
                    "كيف تقرأه": "ما تخسره الزاويتان الخارجيتان مقابل النموذج المسطح"
                },
                {
                    "الحد": "Flat length L",
                    "الصيغة": "L = A + B + BA (flat legs); L = A_out + B_out − BD (outside dims)",
                    "كيف تقرأه": "كلاهما يعطي النتيجة نفسها عندما يكون K صحيحًا — وخلط BA مع BD هو الخطأ الكلاسيكي في النموذج المسطح"
                },
                {
                    "الحد": "Angle convention",
                    "الصيغة": "A = 180° − included angle",
                    "كيف تقرأه": "انحناء 90°: A = 90؛ مشمولة 60°: A = 120؛ مشمولة 120°: A = 60"
                }
            ]
        },
        {
            "caption": "كيف أحسب خصم الانحناء؟",
            "columns": [
                "الحالة",
                "العنصر",
                "القيمة"
            ],
            "rows": [
                {
                    "الحالة": "90°, t 2.0, R 2.0",
                    "العنصر": "OSSB = (2+2)·tan45°",
                    "القيمة": "4.000 mm"
                },
                {
                    "الحالة": "90°, t 2.0, R 2.0",
                    "العنصر": "BD = 2×4.000 − 4.163",
                    "القيمة": "3.837 mm"
                },
                {
                    "الحالة": "90°, t 2.0, R 2.0",
                    "العنصر": "L = 50 + 30 − 3.837",
                    "القيمة": "76.163 mm"
                },
                {
                    "الحالة": "A=120°, t 1.5, R 3.0, 304",
                    "العنصر": "K = (0.65 + 0.5·log10 2)/2",
                    "القيمة": "0.4003"
                },
                {
                    "الحالة": "A=120°, t 1.5, R 3.0, 304",
                    "العنصر": "BA = 2.0944 × (3 + 0.4003×1.5)",
                    "القيمة": "7.541 mm"
                },
                {
                    "الحالة": "A=120°, t 1.5, R 3.0, 304",
                    "العنصر": "OSSB = 4.5 × tan60°",
                    "القيمة": "7.794 mm"
                },
                {
                    "الحالة": "A=120°, t 1.5, R 3.0, 304",
                    "العنصر": "L = 52.206 + 32.206 + 7.541",
                    "القيمة": "91.95 mm"
                },
                {
                    "الحالة": "A=120°, t 1.5, R 3.0, 304",
                    "العنصر": "BD check: 60 + 40 − (2×7.794 − 7.541)",
                    "القيمة": "91.952 mm ✓"
                },
                {
                    "الحالة": "A=120°, t 1.5, R 3.0, 304",
                    "العنصر": "If hard-air K 0.45 instead",
                    "القيمة": "L = 92.11 mm (+0.156 vs DIN 0.40: 0.16 mm per bend)"
                }
            ]
        },
        {
            "caption": "ما فتحة قالب V التي ينبغي استخدامها لفولاذ طري بسماكة 2 mm؟",
            "columns": [
                "t (mm)",
                "V (mm)",
                "R_i (mm)",
                "أدنى شفة (mm)",
                "الحمولة (t/m)",
                "المصدر"
            ],
            "rows": [
                {
                    "t (mm)": "0.5",
                    "V (mm)": "6",
                    "R_i (mm)": "0.96",
                    "أدنى شفة (mm)": "—",
                    "الحمولة (t/m)": "—",
                    "المصدر": "practical min V6, calc"
                },
                {
                    "t (mm)": "0.8",
                    "V (mm)": "6",
                    "R_i (mm)": "0.96",
                    "أدنى شفة (mm)": "—",
                    "الحمولة (t/m)": "—",
                    "المصدر": "S3 method, calc"
                },
                {
                    "t (mm)": "1.0",
                    "V (mm)": "8",
                    "R_i (mm)": "1.3",
                    "أدنى شفة (mm)": "> 5.5",
                    "الحمولة (t/m)": "8",
                    "المصدر": "S3"
                },
                {
                    "t (mm)": "1.5",
                    "V (mm)": "12",
                    "R_i (mm)": "2.0",
                    "أدنى شفة (mm)": "> 8.5",
                    "الحمولة (t/m)": "10",
                    "المصدر": "S3"
                },
                {
                    "t (mm)": "2.0",
                    "V (mm)": "16",
                    "R_i (mm)": "2.6",
                    "أدنى شفة (mm)": "> 11.0",
                    "الحمولة (t/m)": "12",
                    "المصدر": "S3"
                },
                {
                    "t (mm)": "2.5",
                    "V (mm)": "20",
                    "R_i (mm)": "3.3",
                    "أدنى شفة (mm)": "> 14.0",
                    "الحمولة (t/m)": "14",
                    "المصدر": "S3"
                },
                {
                    "t (mm)": "3.0",
                    "V (mm)": "25",
                    "R_i (mm)": "4.0",
                    "أدنى شفة (mm)": "> 17.5",
                    "الحمولة (t/m)": "16",
                    "المصدر": "S3"
                },
                {
                    "t (mm)": "4.0",
                    "V (mm)": "32",
                    "R_i (mm)": "5.0",
                    "أدنى شفة (mm)": "> 22.0",
                    "الحمولة (t/m)": "22",
                    "المصدر": "S3"
                },
                {
                    "t (mm)": "5.0",
                    "V (mm)": "40",
                    "R_i (mm)": "6.5",
                    "أدنى شفة (mm)": "> 28.0",
                    "الحمولة (t/m)": "27",
                    "المصدر": "S3"
                },
                {
                    "t (mm)": "6.0",
                    "V (mm)": "50",
                    "R_i (mm)": "8.0",
                    "أدنى شفة (mm)": "> 35.0",
                    "الحمولة (t/m)": "32",
                    "المصدر": "S3"
                }
            ]
        },
        {
            "caption": "ما معامل K الذي ينبغي استخدامه للفولاذ المقاوم للصدأ 304؟",
            "columns": [
                "المقياس",
                "K عند R≈t",
                "ينطبق على",
                "المصدر"
            ],
            "rows": [
                {
                    "المقياس": "Shop-measured caliber",
                    "K عند R≈t": "0.46",
                    "ينطبق على": "304, air bending, R = t",
                    "المصدر": "S4"
                },
                {
                    "المقياس": "Shop-measured caliber",
                    "K عند R≈t": "0.50",
                    "ينطبق على": "316, air bending, R = t",
                    "المصدر": "S4"
                },
                {
                    "المقياس": "Published hard class (t–3t)",
                    "K عند R≈t": "0.45",
                    "ينطبق على": "Generic 304/316 hard tier — does not separate 304 from 316",
                    "المصدر": "S2/S5"
                },
                {
                    "المقياس": "DIN 6935 at R/t = 2",
                    "K عند R≈t": "0.40",
                    "ينطبق على": "Geometry only — no work-hardening difference",
                    "المصدر": "S1/S6"
                },
                {
                    "المقياس": "This page, Table 2",
                    "K عند R≈t": "0.41–0.45",
                    "ينطبق على": "316 takes the upper bound; test-bend",
                    "المصدر": "S1/S2/S3"
                }
            ]
        },
        {
            "caption": "ما معامل K الذي ينبغي استخدامه لألومنيوم 5052؟",
            "columns": [
                "المقياس",
                "K",
                "ينطبق على",
                "المصدر"
            ],
            "rows": [
                {
                    "المقياس": "Shop-measured (R = t)",
                    "K": "0.33",
                    "ينطبق على": "5052-H32, air bending",
                    "المصدر": "S4"
                },
                {
                    "المقياس": "Published soft air (t–3t)",
                    "K": "0.40",
                    "ينطبق على": "Generic soft aluminium",
                    "المصدر": "S2/S5"
                },
                {
                    "المقياس": "DIN 6935 (R/t = 1.2)",
                    "K": "0.345",
                    "ينطبق على": "Geometry only",
                    "المصدر": "S1/S6"
                },
                {
                    "المقياس": "This page, Table 2",
                    "K": "0.34–0.40",
                    "ينطبق على": "Soft temper low end, hard temper or wide V high end",
                    "المصدر": "S1/S2/S3"
                }
            ]
        },
        {
            "caption": "هل يمكنني استخدام معامل K واحد لكل السماكات؟",
            "columns": [
                "t (mm)",
                "V (mm)",
                "R_i (mm)",
                "R/t",
                "K وفق DIN 6935"
            ],
            "rows": [
                {
                    "t (mm)": "0.5",
                    "V (mm)": "6",
                    "R_i (mm)": "0.96",
                    "R/t": "1.92",
                    "K وفق DIN 6935": "0.40"
                },
                {
                    "t (mm)": "0.8",
                    "V (mm)": "6",
                    "R_i (mm)": "0.96",
                    "R/t": "1.20",
                    "K وفق DIN 6935": "0.34"
                },
                {
                    "t (mm)": "2.0",
                    "V (mm)": "16",
                    "R_i (mm)": "2.56",
                    "R/t": "1.28",
                    "K وفق DIN 6935": "0.35"
                },
                {
                    "t (mm)": "3.0",
                    "V (mm)": "25",
                    "R_i (mm)": "4.00",
                    "R/t": "1.33",
                    "K وفق DIN 6935": "0.36"
                },
                {
                    "t (mm)": "6.0",
                    "V (mm)": "50",
                    "R_i (mm)": "8.00",
                    "R/t": "1.33",
                    "K وفق DIN 6935": "0.36"
                }
            ]
        },
        {
            "caption": "كيف أقيس معامل K الحقيقي لمكبس الثني لدي؟",
            "columns": [
                "الخطوة",
                "القاعدة",
                "القيمة"
            ],
            "rows": [
                {
                    "الخطوة": "1",
                    "القاعدة": "Strip",
                    "القيمة": "200 × 50 mm, bend at 90° mid-length"
                },
                {
                    "الخطوة": "2",
                    "القاعدة": "Measure both outside flanges A_out + B_out",
                    "القيمة": "BD = 200 − (A_out + B_out)"
                },
                {
                    "الخطوة": "3",
                    "القاعدة": "Back-solve",
                    "القيمة": "K = [2(R+t)tan(A/2) − BD] / [(π/180)·A·t] − R/t"
                },
                {
                    "الخطوة": "4",
                    "القاعدة": "Write into CAD material library",
                    "القيمة": "per material + tooling pair"
                }
            ]
        },
        {
            "caption": "أين يقع المحور المحايد في الانحناء؟",
            "columns": [
                "الحالة",
                "K",
                "t (mm)",
                "y = K·t (mm)",
                "نصف القطر المحايد"
            ],
            "rows": [
                {
                    "الحالة": "DC01 2.0 mm, R/t 1.28",
                    "K": "0.35",
                    "t (mm)": "2.0",
                    "y = K·t (mm)": "0.70",
                    "نصف القطر المحايد": "‏R + 0.70 mm (R_i 2.56 → المحايد 3.26 mm)"
                },
                {
                    "الحالة": "DC01 3.0 mm, R/t 1.33",
                    "K": "0.36",
                    "t (mm)": "3.0",
                    "y = K·t (mm)": "1.07",
                    "نصف القطر المحايد": "‏R + 1.07 mm"
                },
                {
                    "الحالة": "304 1.5 mm, R/t 2.13",
                    "K": "0.41",
                    "t (mm)": "1.5",
                    "y = K·t (mm)": "0.61",
                    "نصف القطر المحايد": "‏R + 0.61 mm"
                },
                {
                    "الحالة": "DC01 6.0 mm, R/t 1.33",
                    "K": "0.36",
                    "t (mm)": "6.0",
                    "y = K·t (mm)": "2.14",
                    "نصف القطر المحايد": "‏R + 2.14 mm"
                }
            ]
        },
        {
            "caption": "لماذا يُظهر السك أحيانًا معامل K أقل من الانحناء إلى القاع؟",
            "columns": [
                "الطريقة",
                "K للطري (t–3t)",
                "K للمتوسط (t–3t)",
                "K للصلب (t–3t)",
                "المصدر"
            ],
            "rows": [
                {
                    "الطريقة": "Bottoming",
                    "K للطري (t–3t)": "0.46",
                    "K للمتوسط (t–3t)": "0.47",
                    "K للصلب (t–3t)": "0.48",
                    "المصدر": "S2/S5"
                },
                {
                    "الطريقة": "Coining",
                    "K للطري (t–3t)": "0.44",
                    "K للمتوسط (t–3t)": "0.46",
                    "K للصلب (t–3t)": "0.47",
                    "المصدر": "S2/S5"
                },
                {
                    "الطريقة": "Expectation",
                    "K للطري (t–3t)": "—",
                    "K للمتوسط (t–3t)": "—",
                    "K للصلب (t–3t)": "—",
                    "المصدر": "—"
                },
                {
                    "الطريقة": "Second source confirming the ranking",
                    "K للطري (t–3t)": "none found",
                    "K للمتوسط (t–3t)": "none found",
                    "K للصلب (t–3t)": "none found",
                    "المصدر": "GAP"
                }
            ]
        }
    ]
}