Typical component families for eyewear manufacturing — hinge bodies, eyewear screws, hinge pins and cold-forged blanks in brass and stainless — with the cold forging plus CNC turning combination this category runs on.
| Hinge bodies / box | Brass CuZn39Pb3, stainless |
| Eyewear screws Ø1.0–1.8 | Stainless, nickel-plated brass |
| Cold-forged blanks | Brass, steel, forged 60–180 T |
| Batch range | 10,000–50,000+ pcs per family |
| Tolerance scheme | ±0.005 mm on guide diameters |
| Documentation | EN 10204 3.1, RoHS/REACH |
Eyewear manufacturers concentrate on design, brands and final assembly; the hinge — bodies, screws, pins and the cold-forged blanks they start from — is almost universally outsourced. The category runs on a two-process combination: cold forging for the near-net blanks and CNC Swiss turning for the finished precision features.
Component families are variant-rich (screw lengths, pin diameters, body styles per collection) and demand tight guide-diameter tolerances, 100% thread checks and plating-ready surfaces — with collections refreshing every season, stable repeat supply matters as much as the first approval.
| Component (IT / EN) | Typical material | Process | Typical batch |
|---|---|---|---|
| corpi cerniera / box (hinge bodies) | CuZn39Pb3 brass, stainless | Swiss-type turning | ≥10,000 pcs |
| viti occhialeria Ø1.0–1.8 (eyewear screws) | stainless, nickel-plated brass | Swiss turning + thread rolling | ≥50,000 pcs |
| perni / pernolini (hinge pins) | 303 stainless, brass | Swiss turning + grinding | ≥10,000 pcs |
| semilavorati a freddo (cold-forged blanks) | brass, steel | cold forging (60–180 T) | ≥30,000 pcs |
Guide diameters are held to ±0.005 mm, threads are checked 100%, and plating (nickel or nickel-free on request) plus aesthetic finishes are confirmed on samples per collection.
The standard flow: drawing review and quotation within 48 hours, first samples in 7–15 days, first article inspection and approval, then series production against the approved reference. Tooling, program revisions and inspection records are kept on file so that call-offs remain consistent with the approved first article.
Engineering changes — material substitutions, tolerance updates, plating or packaging changes — are handled as controlled changes against the same records.
DIN ISO 2768-mK applies as the default tolerance scheme for unspecified dimensions. EN 10204 3.1 inspection certificates are standard for metallic parts, First Article Inspection supports the approval step, and RoHS/REACH declarations are available where required. Plating, cleanliness and packaging requirements are confirmed per drawing.
Can you develop hinges from a technical drawing?
Yes — from 2D/3D drawing to approved sample, with a dimensional report on every guide feature.
What are the economic minimums?
Swiss-turned parts from 10,000 pieces; cold-forged blanks from 30,000 pieces. Both routes can be quoted side by side for comparison.
Which finishes can you prepare for?
Nickel plating (nickel-free on request) and dark finishes via partners; aesthetic surfaces (mirror/satin) are confirmed on samples.
Which documents accompany the parts?
EN 10204 3.1 certificates and RoHS/REACH declarations as standard; dimensional reports per batch.
Send your drawing — Sinbo Precision will review material, tolerance scheme and batch plan and return a quotation within 48 hours. Samples in 7–15 days.
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