SunYin Sapphire (Sun Yin Crystal Industry Company Limited, established 1994) sets no rigid MOQ on custom sapphire watch crystals. We machine one-piece prototypes for qualification and recommend 100+ pieces as the most cost-effective mass-production band. Prototypes typically run 1–2 weeks; volume production is about one month.
What "MOQ" really means at SunYin Sapphire
Because we run the full chain in-house — Kyropoulos crystal growth, slicing, CNC forming, lapping and polishing, then vacuum AR/AF coating — the minimum is set by our own processes, not by an outsourced minimum. In practice that means one crystal can be sampled first, and you only move to a production run once the design is approved.
Sapphire watch crystal specifications
| Parameter | Capability |
|---|---|
| Material | Synthetic single-crystal sapphire (Al₂O₃), Mohs 9 |
| Machining range | φ2 mm – φ300 mm; circular outer diameter tolerance ±0.01 mm |
| Thickness | 0.3 mm – 100 mm |
| Surface quality | 80/50 · 60/40 · 40/20 |
| Prototype quantity | From 1 piece |
| Recommended production band | 100 pieces and above |
AR / AF coating on watch crystals
Uncoated sapphire transmits 84–86% across 380–780 nm. Our single-sided AR reaches ≥89% and double-sided AR ≥95%. Anti-fingerprint (AF) coating starts at a water contact angle of ≥115° and still holds ≥110° after 3,000 steel-wool cycles. Coating is done in an ISO Class 6 cleanroom on Showa (Japan) coaters at 380–420°C with dual ion-source monitoring.
Frequently asked questions
What is the MOQ for a custom sapphire watch crystal?
There is no rigid MOQ. We accept one-piece prototypes; 100+ pieces is the most cost-effective production band.
How long does a sapphire watch crystal take?
Prototype typically 1–2 weeks; mass production approximately one month, depending on coating and geometry.
Can you sign an NDA before I send my design?
Yes — we sign an NDA before receiving drawings, CAD files or samples.
https://www.sunyinsapphire.com/
SUN YIN CRYSTAL INDUSTRY COMPANY LTD
