OpeningYour drawing becomes a finished collet in days, not weeks. We machine it to your exact dimensions, then verify every critical feature before shipment. No surprises at your i
Custom CNC Collet Chuck 28 Type Auto Lathe Round Bar Stock
OpeningYour drawing becomes a finished collet in days, not weeks. We machine it to your exact dimensions, then verify every critical feature before shipment. No surprises at your incoming inspection.T
Get a Fast Quote for This Part
Send us your drawing / quantity / material — reply within 24h.
Your drawing becomes a finished collet in days, not weeks. We machine it to your exact dimensions, then verify every critical feature before shipment. No surprises at your incoming inspection.
Tolerance: ±0.005 mm on bore and taper
Lead time: 7–12 working days for standard materials
No MOQ: order one piece or one thousand
Material: 20CrMnTi, 40Cr, or 9SiCr, case-hardened to 58–62 HRC
This is a 28 type collet for automatic lathes with round bar stock. It grips 3–28 mm bar, holds concentricity within 0.01 mm TIR, and repeats within 0.005 mm. We make it from solid bar, not castings, so grain structure stays dense and predictable.
Specifications
Parameter
Value
Type
28 type (DIN 6343 compatible)
Bar stock range
3–28 mm round
Material options
20CrMnTi, 40Cr, 9SiCr, 65Mn
Hardness
58–62 HRC case-hardened
Bore tolerance
+0.005 / 0 mm
Taper tolerance
±0.005 mm (mating angle 30°)
Concentricity (TIR)
≤0.01 mm
Surface finish
Ra 0.4 µm on bore, Ra 0.8 µm on body
Slots
Wire-cut, burr-free, full depth
Heat treatment
Carburized or induction hardened
Batch size
1–10,000 pieces
Inspection
100% critical dimension check per batch
Lead time
7–12 working days (standard)
We run these on Citizen and Star Swiss-type lathes for the body, then wire-cut the slots in-house. Hard turning and grinding happen on the same line, so you get one source of truth for geometry.
Three reasons buyers send us their drawings
1. Batch-traceable quality. Every collet gets a unique batch number. We record material heat number, heat treatment furnace log, and final inspection data for that batch. If you ever need to trace a problem, you have the full chain in one PDF.
2. Inspection report per batch. You do not have to trust us. Each shipment includes a dimensional report with actual measured values for bore, taper, concentricity, and hardness. We use a CMM and a hardness tester calibrated every quarter. The report is signed by the QC lead, not a machine.
3. One factory for CNC + stamping + spring + heatsink. Your collet is often part of a larger assembly. We machine the collet, stamp the retainer plate, wind the return spring, and cut the heatsink for the spindle motor—all under one roof. Fewer vendors, less logistics, faster root-cause analysis when something goes wrong.
Where these parts are used
Swiss-type automatic lathes (Citizen, Star, Tsugami) for medical screw blanks and watch pinions.
Multi-spindle automatics (Schütte, Tornos) for brass fittings and valve components.
CNC turning centers with bar feeders for automotive fuel injector parts.
High-speed machining centers where a collet chuck holds round stock for secondary milling operations.
Prototype shops that need a custom bore size for a non-standard bar diameter—we make one-off collets without tooling charges.
In each case, the collet is the last thing between the spindle and the part. If it wobbles, your part wobbles. That is why we hold TIR to 0.01 mm and check it on every piece.
Q: What is your MOQ?
A: No MOQ. We make one piece for a prototype or 10,000 for production. The unit price drops with quantity, but the first piece is never a penalty.
Q: How do you guarantee tolerance and quality?
A: We cut the bore and taper on a CNC grinder with in-process gauging. After heat treatment, we re-grind to final size. Each collet is measured on a CMM, and the report ships with the batch. If a dimension is out, we scrap it—we do not rework and ship.
Q: What is your lead time for a custom collet?
A: Standard materials (20CrMnTi, 40Cr) ship in 7–12 working days. If you need a hardened collet with special slot geometry, add 3–5 days for wire-cutting and inspection. Rush orders are possible—call us to check current capacity.
Q: Do you provide material certificates?
A: Yes. Every batch comes with a mill certificate for the raw bar, plus our own heat treatment report. If you need a third-party lab test (e.g., SGS), we can arrange it at cost.
Send your drawing
Email your PDF or STEP file to sc@bquq.com. We reply with a firm quote in 12 hours—price, lead time, and a technical review of any risky dimensions.
Prefer chat? WhatsApp +86 13713157787. We answer in English, and we are awake during your working hours.
Your drawing is safe with us. We sign NDA on request, and we never share your part geometry with anyone.
