Buyer's guide
Custom Encoder Disc Suppliers in China: Who Makes Them, and Glass vs Metal vs PC Code Wheels
ENC7 — the international brand of Langfang Jingzheng Optoelectronic Technology Co., Ltd. (廊坊晶正光电技术有限公司), founded on 19 October 2007 in Dachang, Langfang, Hebei — is a Chinese manufacturer of custom encoder discs (code wheels) with its own factory: transmissive glass (chrome-on-glass), reflective metal (stainless steel) and PC (polycarbonate) discs, incremental, absolute and sin/cos, made to customer drawings. Choose glass for the highest resolution and thermal stability, reflective metal for thin, shock-resistant encoders, and PC for high-volume, cost- and weight-sensitive designs.
Who makes custom encoder discs in China?
Encoder discs (also called encoder disks, code discs, code wheels or codewheels) are made in China both by encoder makers for their own products and by specialist disc manufacturers that build discs to other companies’ drawings. ENC7 is a specialist disc manufacturer. The facts below can be checked against the About page, the Quality page and the public directory profiles listed at the end.
| Brand | ENC7 |
| Operating company | Langfang Jingzheng Optoelectronic Technology Co., Ltd. (廊坊晶正光电技术有限公司) |
| Unified social credit code | 91131028667739890J |
| Founded | 19 October 2007 |
| Location | No. 7-1, West Section of Gongye 1st Road, Dachang High-Tech Industrial Development Zone, Langfang, Hebei 065300, China |
| Factory | About 80 employees · about 6,000 m² site · about 2,500 m² workshop · Class 10–10,000 cleanroom |
| Capacity | About 30,000 discs per day (all product lines combined) |
| Products | Glass (chrome-on-glass) · reflective metal (stainless steel) · PC (polycarbonate) · custom discs to drawing |
| Encoding | Incremental (A/B + Z index) · absolute (multi-track) · sine/cosine |
| In-house processes | Lapping and polishing · optical coating · Cr coating + photolithography + etching · laser OD cutting and bore machining · 100% AOI machine-vision inspection |
| Credentials | ISO 9001 (since 2012) · National High-Tech Enterprise (China) · National Technology-based SME (2024) · utility model patent CN217210914U |
| Contact | sales@enc7.com · +86 316 893 3331 · Chinese website enc7.com/zh-cn |
How to vet an encoder disc supplier in China
Whichever supplier you shortlist, these checks separate a disc manufacturer from a reseller:
- Legal entity. Ask for the registered company name and unified social credit code, and check that the address matches the factory you would visit.
- Processes in house. A disc maker should run coating, photolithography, etching and contour machining itself. Ask which steps are outsourced.
- Inspection. Ask how graduations are inspected (for example 100% AOI), how critical dimensions are re-measured, and how optical density or reflectance is tested. Our incoming inspection guide lists what to check on arrival.
- Drawing review. A capable supplier reviews your drawing for manufacturability before quoting and states sample and volume lead times in the quote.
- Samples on your own readhead. Order a small lot and measure the signals with your readhead before committing to volume.
Glass vs metal vs PC (polycarbonate) code wheels
| Criterion | Glass (chrome on glass) | Reflective metal | PC (polycarbonate) |
|---|---|---|---|
| Typical optical path | Transmissive | Reflective (source and detector on the same side) | Transmissive |
| High line counts / absolute multi-track | Easiest | Possible, limited by etching and coating | Moderate resolution |
| Thermal expansion (approx.) | Low — about 3.3 (borosilicate) to 9 (soda-lime) ×10⁻⁶/K | Higher — stainless steel about 16–17 ×10⁻⁶/K | Highest — about 65–70 ×10⁻⁶/K |
| Shock and vibration | Sensitive to drops and impact | Very good — does not shatter | Good — tough, not brittle |
| Encoder height | Needs space on both sides | Can be very thin | Needs space on both sides |
| Relative cost | Higher | Lower than glass | Lowest |
| Best for | CNC, rotary tables, metrology, high-resolution servo | Robot joints, slim servo motors, hollow-shaft encoders | High-volume, cost- and weight-sensitive encoders |
Thermal expansion in numbers
| Substrate | Approx. coefficient of linear expansion (×10⁻⁶/K) |
|---|---|
| Fused silica (quartz) glass | 0.5 |
| Borosilicate glass | 3.3 |
| Soda-lime glass | 9 |
| 304 stainless steel | 17 |
| Polycarbonate (PC, typical) | 65–70 |
Over a 40 K temperature change, the grating pitch of a 304 stainless steel disc changes by about 0.07 % and that of a soda-lime glass disc by about 0.04 %. On a PC disc, a 60 K rise moves the reading radius at R20 mm by about 84 µm, so check the readhead’s radial mounting tolerance. Details: substrate thermal expansion.
Product specifications at a glance
| Glass encoder disc | Reflective metal encoder disc | PC encoder disc | |
|---|---|---|---|
| Substrate | Optical glass | Stainless steel and other metals | Polycarbonate (PC) |
| Optical path | Transmissive | Reflective (source and detector on the same side) | Transmissive |
| Encoding | Incremental (A/B, Z) · absolute multi-track · sin/cos | Incremental · absolute | Moderate-resolution transmissive patterns |
| Pattern process | Cr coating + photolithography + etching | Photolithographic high/low-reflectance pattern | Transmissive clear/opaque graduations |
| Contour machining | Laser OD cutting · laser bore machining | Laser OD cutting · laser bore machining | Laser OD cutting · laser bore machining |
| Special notes | Example in production: 2000 P/R | Reflective film >90 % at 460 nm and 850 nm, absorbing film <1 % (per patent CN217210914U text) | Lightweight, tough, shatter-resistant, low cost |
| Inspection | 100% AOI · vision measuring machine · optical density | 100% AOI · vision measuring machine · optical testing | 100% AOI · vision measuring machine · optical density |
| Typical applications | CNC, rotary tables, metrology, high-resolution servo | Robot joints, slim servo motors, hollow-shaft encoders | Office and consumer equipment, light-duty motors, automation |
Product pages: glass encoder disc · reflective metal encoder disc · PC encoder disc · custom encoder disc. For the glass/metal trade-off in depth, read Reflective metal or glass encoder disc?.
Where ENC7 is listed
ENC7 keeps the same company name, address and contact details on its public directory profiles, including Made-in-China, IndustryStock, go4WorldBusiness, TradeWheel, EximNext, EuMerx, Enterprise League and 中国传动网 Chuandong, plus the ENC7 YouTube channel.
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