{
    "slug": "standard-tolerances",
    "title": "CNC 零件通用公差：ISO 2768 和 IT 等级",
    "description": "ISO 2768 线性尺寸通用公差表，含 f/m/c/v 四种精度等级逐档数值、IT01 至 IT18 公差等级换算，以及车、铣、磨、线切割各工艺实际能达到的公差。",
    "lang": "zh",
    "tables": [
        {
            "caption": "线性尺寸的 ISO 2768-1 通用公差（mm）",
            "columns": [
                "公称尺寸范围（mm）",
                "ISO 2768-f",
                "ISO 2768-m",
                "ISO 2768-c",
                "ISO 2768-v"
            ],
            "rows": [
                {
                    "公称尺寸范围（mm）": "0.5 – 3",
                    "ISO 2768-f": "±0.05",
                    "ISO 2768-m": "±0.1",
                    "ISO 2768-c": "±0.2",
                    "ISO 2768-v": "—"
                },
                {
                    "公称尺寸范围（mm）": "3 – 6",
                    "ISO 2768-f": "±0.05",
                    "ISO 2768-m": "±0.1",
                    "ISO 2768-c": "±0.3",
                    "ISO 2768-v": "±0.5"
                },
                {
                    "公称尺寸范围（mm）": "6 – 30",
                    "ISO 2768-f": "±0.1",
                    "ISO 2768-m": "±0.2",
                    "ISO 2768-c": "±0.5",
                    "ISO 2768-v": "±1.0"
                },
                {
                    "公称尺寸范围（mm）": "30 – 120",
                    "ISO 2768-f": "±0.15",
                    "ISO 2768-m": "±0.3",
                    "ISO 2768-c": "±0.8",
                    "ISO 2768-v": "±1.5"
                },
                {
                    "公称尺寸范围（mm）": "120 – 400",
                    "ISO 2768-f": "±0.2",
                    "ISO 2768-m": "±0.5",
                    "ISO 2768-c": "±1.2",
                    "ISO 2768-v": "±2.5"
                },
                {
                    "公称尺寸范围（mm）": "400 – 1000",
                    "ISO 2768-f": "±0.3",
                    "ISO 2768-m": "±0.8",
                    "ISO 2768-c": "±2.0",
                    "ISO 2768-v": "±4.0"
                },
                {
                    "公称尺寸范围（mm）": "1000 – 2000",
                    "ISO 2768-f": "±0.5",
                    "ISO 2768-m": "±1.2",
                    "ISO 2768-c": "±3.0",
                    "ISO 2768-v": "±6.0"
                },
                {
                    "公称尺寸范围（mm）": "2000 – 4000",
                    "ISO 2768-f": "—",
                    "ISO 2768-m": "±2.0",
                    "ISO 2768-c": "±4.0",
                    "ISO 2768-v": "±8.0"
                }
            ]
        },
        {
            "caption": "应指定哪个精度等级",
            "columns": [
                "等级",
                "精度级别",
                "典型用途",
                "成本影响"
            ],
            "rows": [
                {
                    "等级": "f (fine)",
                    "精度级别": "最高通用精度",
                    "典型用途": "精密零件、无需特定配合的配合面、严格的外观要求",
                    "成本影响": "相较中等等级：+15–30%"
                },
                {
                    "等级": "m (medium)",
                    "精度级别": "标准 CNC",
                    "典型用途": "通用 CNC 机加工零件。应用最广的等级，适用于大多数加工零件。",
                    "成本影响": "基准"
                },
                {
                    "等级": "c (coarse)",
                    "精度级别": "宽松",
                    "典型用途": "钣金零件、结构焊接件、非关键铸件、大型装配组件",
                    "成本影响": "相比中等等级：−10–20%"
                },
                {
                    "等级": "v (very coarse)",
                    "精度级别": "最宽松",
                    "典型用途": "焊接结构、毛坯铸件、非精密制造件、超大尺寸",
                    "成本影响": "相比中等等级：−20–35%"
                }
            ]
        },
        {
            "caption": "IT 等级——公差数值的含义",
            "columns": [
                "IT 等级",
                "实际含义",
                "1–3 mm",
                "6–10 mm",
                "18–30 mm",
                "50–80 mm",
                "120–180 mm",
                "250–315 mm"
            ],
            "rows": [
                {
                    "IT 等级": "IT01",
                    "实际含义": "量块基准",
                    "1–3 mm": "0.3",
                    "6–10 mm": "0.4",
                    "18–30 mm": "0.6",
                    "50–80 mm": "0.8",
                    "120–180 mm": "1.0",
                    "250–315 mm": "1.2"
                },
                {
                    "IT 等级": "IT0",
                    "实际含义": "参考标准",
                    "1–3 mm": "0.5",
                    "6–10 mm": "0.6",
                    "18–30 mm": "0.9",
                    "50–80 mm": "1.2",
                    "120–180 mm": "1.5",
                    "250–315 mm": "2.0"
                },
                {
                    "IT 等级": "IT1",
                    "实际含义": "精密量规",
                    "1–3 mm": "0.8",
                    "6–10 mm": "1.0",
                    "18–30 mm": "1.5",
                    "50–80 mm": "2.0",
                    "120–180 mm": "2.5",
                    "250–315 mm": "3.0"
                },
                {
                    "IT 等级": "IT2",
                    "实际含义": "高精度量具",
                    "1–3 mm": "1.2",
                    "6–10 mm": "1.5",
                    "18–30 mm": "2.5",
                    "50–80 mm": "3.0",
                    "120–180 mm": "4.0",
                    "250–315 mm": "5.0"
                },
                {
                    "IT 等级": "IT3",
                    "实际含义": "超精密加工",
                    "1–3 mm": "2.0",
                    "6–10 mm": "2.5",
                    "18–30 mm": "4.0",
                    "50–80 mm": "5.0",
                    "120–180 mm": "6.0",
                    "250–315 mm": "8.0"
                },
                {
                    "IT 等级": "IT4",
                    "实际含义": "精密磨削 / 线切割",
                    "1–3 mm": "3",
                    "6–10 mm": "4",
                    "18–30 mm": "6",
                    "50–80 mm": "8",
                    "120–180 mm": "10",
                    "250–315 mm": "13"
                },
                {
                    "IT 等级": "IT5",
                    "实际含义": "量具制造",
                    "1–3 mm": "4",
                    "6–10 mm": "6",
                    "18–30 mm": "9",
                    "50–80 mm": "13",
                    "120–180 mm": "16",
                    "250–315 mm": "20"
                },
                {
                    "IT 等级": "IT6",
                    "实际含义": "精密加工",
                    "1–3 mm": "6",
                    "6–10 mm": "9",
                    "18–30 mm": "13",
                    "50–80 mm": "19",
                    "120–180 mm": "25",
                    "250–315 mm": "32"
                },
                {
                    "IT 等级": "IT7",
                    "实际含义": "精密配合（轴承、轴）",
                    "1–3 mm": "10",
                    "6–10 mm": "15",
                    "18–30 mm": "21",
                    "50–80 mm": "30",
                    "120–180 mm": "40",
                    "250–315 mm": "52"
                },
                {
                    "IT 等级": "IT8",
                    "实际含义": "一般精密加工",
                    "1–3 mm": "14",
                    "6–10 mm": "22",
                    "18–30 mm": "33",
                    "50–80 mm": "46",
                    "120–180 mm": "63",
                    "250–315 mm": "81"
                },
                {
                    "IT 等级": "IT9",
                    "实际含义": "一般加工（等同于 ISO 2768-m）",
                    "1–3 mm": "25",
                    "6–10 mm": "36",
                    "18–30 mm": "52",
                    "50–80 mm": "74",
                    "120–180 mm": "100",
                    "250–315 mm": "130"
                },
                {
                    "IT 等级": "IT10",
                    "实际含义": "中等精度",
                    "1–3 mm": "40",
                    "6–10 mm": "58",
                    "18–30 mm": "84",
                    "50–80 mm": "120",
                    "120–180 mm": "160",
                    "250–315 mm": "210"
                },
                {
                    "IT 等级": "IT11",
                    "实际含义": "宽松加工",
                    "1–3 mm": "60",
                    "6–10 mm": "90",
                    "18–30 mm": "130",
                    "50–80 mm": "190",
                    "120–180 mm": "250",
                    "250–315 mm": "320"
                },
                {
                    "IT 等级": "IT12",
                    "实际含义": "非常粗糙的加工",
                    "1–3 mm": "100",
                    "6–10 mm": "150",
                    "18–30 mm": "210",
                    "50–80 mm": "300",
                    "120–180 mm": "400",
                    "250–315 mm": "500"
                },
                {
                    "IT 等级": "IT13",
                    "实际含义": "模型和粗加工",
                    "1–3 mm": "140",
                    "6–10 mm": "220",
                    "18–30 mm": "310",
                    "50–80 mm": "440",
                    "120–180 mm": "580",
                    "250–315 mm": "740"
                },
                {
                    "IT 等级": "IT14",
                    "实际含义": "粗糙、低等级加工",
                    "1–3 mm": "250",
                    "6–10 mm": "370",
                    "18–30 mm": "520",
                    "50–80 mm": "740",
                    "120–180 mm": "1000",
                    "250–315 mm": "1250"
                },
                {
                    "IT 等级": "IT15",
                    "实际含义": "非常粗糙",
                    "1–3 mm": "400",
                    "6–10 mm": "600",
                    "18–30 mm": "840",
                    "50–80 mm": "1200",
                    "120–180 mm": "1600",
                    "250–315 mm": "2000"
                },
                {
                    "IT 等级": "IT16",
                    "实际含义": "近似 / 未指定",
                    "1–3 mm": "600",
                    "6–10 mm": "1000",
                    "18–30 mm": "1400",
                    "50–80 mm": "2000",
                    "120–180 mm": "2600",
                    "250–315 mm": "3200"
                },
                {
                    "IT 等级": "IT17",
                    "实际含义": "非常近似",
                    "1–3 mm": "1000",
                    "6–10 mm": "1600",
                    "18–30 mm": "2400",
                    "50–80 mm": "3300",
                    "120–180 mm": "4300",
                    "250–315 mm": "5300"
                },
                {
                    "IT 等级": "IT18",
                    "实际含义": "一般制品加工",
                    "1–3 mm": "1400",
                    "6–10 mm": "2500",
                    "18–30 mm": "3500",
                    "50–80 mm": "4800",
                    "120–180 mm": "6300",
                    "250–315 mm": "7600"
                }
            ]
        },
        {
            "caption": "各 CNC 加工工艺实际能够保证的精度",
            "columns": [
                "工艺",
                "标准（典型）",
                "精密（额外成本）",
                "超精密（成本高）",
                "IT 等效值"
            ],
            "rows": [
                {
                    "工艺": "CNC Milling (3-axis)",
                    "标准（典型）": "±0.025mm",
                    "精密（额外成本）": "±0.005mm",
                    "超精密（成本高）": "±0.002mm",
                    "IT 等效值": "IT8 → IT5 → IT3"
                },
                {
                    "工艺": "CNC Milling (5-axis)",
                    "标准（典型）": "±0.010mm",
                    "精密（额外成本）": "±0.005mm",
                    "超精密（成本高）": "±0.002mm",
                    "IT 等效值": "IT7 → IT5 → IT3"
                },
                {
                    "工艺": "CNC Turning",
                    "标准（典型）": "±0.025mm",
                    "精密（额外成本）": "±0.005mm",
                    "超精密（成本高）": "±0.002mm",
                    "IT 等效值": "IT8 → IT5 → IT3"
                },
                {
                    "工艺": "Swiss-Type Turning",
                    "标准（典型）": "±0.010mm",
                    "精密（额外成本）": "±0.005mm",
                    "超精密（成本高）": "±0.002mm",
                    "IT 等效值": "IT7 → IT5 → IT3"
                },
                {
                    "工艺": "Surface Grinding",
                    "标准（典型）": "±0.005mm",
                    "精密（额外成本）": "±0.002mm",
                    "超精密（成本高）": "±0.001mm",
                    "IT 等效值": "IT5 → IT3 → IT2"
                },
                {
                    "工艺": "Jig Boring",
                    "标准（典型）": "±0.010mm",
                    "精密（额外成本）": "±0.005mm",
                    "超精密（成本高）": "±0.002mm",
                    "IT 等效值": "IT7 → IT5 → IT3"
                },
                {
                    "工艺": "Wire EDM",
                    "标准（典型）": "±0.010mm",
                    "精密（额外成本）": "±0.003mm",
                    "超精密（成本高）": "±0.001mm",
                    "IT 等效值": "IT7 → IT4 → IT2"
                },
                {
                    "工艺": "Sinker EDM",
                    "标准（典型）": "±0.015mm",
                    "精密（额外成本）": "±0.005mm",
                    "超精密（成本高）": "±0.002mm",
                    "IT 等效值": "IT8 → IT5 → IT3"
                }
            ]
        }
    ]
}