OpeningWe machine ER20 spring collets to your exact drawing. Not from stock blanks. Not modified from standard sizes. We start from bar stock and cut every profile, slot, and taper to your specified d
We machine ER20 spring collets to your exact drawing. Not from stock blanks. Not modified from standard sizes. We start from bar stock and cut every profile, slot, and taper to your specified dimensions.
Each collet is verified before shipment. We check the critical taper angle, slot width, and concentricity on a CMM. You get the numbers, not just a "passed" stamp.
At a glance: Tolerance ±0.005 mm on the bore, surface finish Ra 0.4, lead time 7–12 days, no MOQ. One collet or one thousand, same process.
| Parameter | Value |
|---|---|
| Material options | 65Mn spring steel, 60Si2MnA, 9Cr18 stainless, or per drawing |
| Hardness | HRC 45–52 (through-hardened, not case-hardened) |
| Taper angle | 8° per side, verified with air gauge |
| Bore tolerance | H5 (+0.008 / 0) or tighter per drawing |
| Concentricity | ≤ 0.005 mm TIR at nose |
| Surface finish | Ra 0.4 on taper, Ra 0.8 on slots |
| Slot width | ±0.02 mm, burr-free edges |
| Process | CNC turning, CNC milling, wire EDM for slots, heat treatment |
| Heat treatment | Vacuum hardening, no decarb layer |
| Batch size | 1 to 10,000 pieces |
| Inspection | 100% taper check, 30% full dimension report per batch |
| Lead time | 7 days for prototypes, 12 days for production |
We use 5-axis CNC turning centers for the taper and bore. Slots are cut with wire EDM to avoid tool deflection. Heat treatment is done in-house in a vacuum furnace, so we control the hardness curve, not a subcontractor.
1. Batch-traceable quality. Every collet gets a heat treatment lot number. We record the furnace cycle, the material heat number, and the final hardness reading. If you have a problem at tool #47, we can pull the exact batch record and tell you the hardness, the taper measurement, and the operator. No guesswork.
2. Inspection report per batch. You do not have to ask for it. Each shipment includes a dimensional report with actual measured values for taper angle, bore diameter, slot width, and concentricity. We use a Zeiss CMM and a calibrated air gauge. The report is signed by QC, not generated by software.
3. One factory for CNC, stamping, springs, and heat sinks. This is precision manufacturing with no middlemen. Your collet chuck assembly might need a spring, a stamped retainer, or a heat sink for the spindle drive. We make all of them under one roof. You send one drawing package, get one quote, one set of QC reports, and one shipment. Fewer vendors, fewer tolerance stack-ups, fewer arguments.
ER20 collets are the workhorse of high-speed machining centers and CNC lathes. Typical applications:
We also make custom ER20 variants: longer noses for deep reach, slotted versions for coolant-through, and hardened steel versions for high-clamping-force applications. If your drawing says "ER20 but different," we can make it.
Looking for a different part? We also machine Custom CNC Machined ER40 Spring Collet Chuck for End Mill Milling in the same Dongguan factory.
Q: What is the MOQ? A: No MOQ. We quote and make one piece. The per-piece price for a single collet is higher than for 100 pieces, but the process is identical. We do not batch small orders with other customers' work.
Q: How do you guarantee tolerance and quality? A: The taper angle is measured with an air gauge, not a comparator. The bore is measured with a bore gauge calibrated to NIST standards. Each batch gets a written inspection report. If any dimension is out of spec, we scrap the part, not ship it.
Q: What is the lead time for a custom CNC collet chuck? A: Prototype (1–5 pieces) is 7 days. Production (50+ pieces) is 10–12 days. Heat treatment adds 2 days, but it is included in those numbers. We do not quote "up to 4 weeks" to be safe. We quote what we can deliver.
Q: Can you provide material certificates? A: Yes. We supply mill certificates for the raw material, heat treatment reports with actual hardness curves, and a certificate of conformity. All documents are in English. We can also provide third-party inspection (SGS or BV) at your cost.
Email your PDF or STEP file to sc@bquq.com. Include the material, hardness, and quantity if you know them. If you do not, we will recommend based on your application.
We reply with a firm quote in 12 hours. Not a "budget range." A fixed price per piece, tooling cost (if any), and delivery date.
For urgent projects, WhatsApp us at +86 13713157787. We answer 7 days a week, 8:00–22:00 Beijing time.
Custom CNC collet chuck, made in China, with no MOQ and no surprises. Send the drawing. Get the quote.
| Parameter | Capability |
|---|---|
| Materials | AL6061/7075, SUS303/304/316, 45# steel, T2 copper, H59 brass, POM, PEEK, nylon |
| Tolerance | ±0.005mm standard, ±0.003mm on request |
| Machines | 3/4/5-axis CNC, turn-mill, Swiss lathe |
| Surface | Anodizing, nickel, zinc, passivation, sandblast, polish |
| Size Range | Max 400 x 300 x 200 mm |
| Prototype | 72 hours, no MOQ on samples |
| Inspection | Full report per batch, CMM data on request |
