OpeningYour drawing defines the bore. We machine the rest to match. This is a 20-type square bore spring collet, built for auto lathes that demand concentric grip and repeatable release. We cut it fro
Your drawing defines the bore. We machine the rest to match. This is a 20-type square bore spring collet, built for auto lathes that demand concentric grip and repeatable release. We cut it from solid stock, heat-treat it for spring memory, and verify the square bore geometry before shipment.
No guesswork. No off-the-shelf approximations. You send the print; we hold the tolerance.
At a glance: ±0.005 mm on bore dimensions, 10-15 working days lead time, no MOQ, material certs included with every batch.
| Parameter | Value |
|---|---|
| Material options | Spring steel 65Mn, 60Si2MnA, alloy steel 20CrMnTi, stainless 17-4PH |
| Hardness (after heat treat) | 40-52 HRC, per drawing requirement |
| Bore tolerance | ±0.005 mm on square width and corner radius |
| Concentricity (bore to taper) | ≤0.01 mm TIR |
| Surface finish | Ra 0.4 µm on bore, Ra 0.8 µm on taper |
| Process | CNC turning, CNC milling, wire EDM for square bore, heat treatment, OD/ID grinding |
| Square bore size range | 3 mm to 20 mm width (per 20-type collet standard) |
| Taper angle | 30° or 45°, per your drawing |
| Batch size | 1 piece to 10,000 pieces |
| Inspection | 100% dimensional check on bore, sample CMM report per batch |
| Lead time | 10-15 working days for standard materials, 20 days for stainless |
| Country of origin | Made in China, Dongguan factory |
All collets are stress-relieved after rough machining and before final grinding. This prevents distortion when the collet is clamped and released thousands of times per shift.
1. Batch-traceable quality, not just a one-off sample. Every collet gets a unique batch number. We record material heat number, heat treatment furnace log, and final inspection data against that number. If you need to trace a problem in your production line, you can go back to the exact batch and the exact machine cycle. This matters when you run 24/7 auto lathes and a bad collet stops a line.
2. Inspection report per batch, included free. You get a dimensional report for every batch we ship. It lists bore width, corner radius, concentricity, hardness, and surface finish. We do not ask you to trust us. We give you numbers. If a dimension is out of spec, we catch it before packing, not after you mount it on your spindle.
3. One factory for CNC, stamping, springs, and heat sinks. Your collet is not an isolated part. It works inside a chuck that may also use springs, stamped retainers, or a heat sink for thermal stability. We make all of those in the same facility. You send one drawing package, deal with one quality team, and receive one consolidated shipment. Fewer suppliers, fewer handoff errors, shorter total lead time.
A 20-type square bore spring collet is not a general-purpose tool. It is specified for auto lathes and Swiss-type machines that feed square or rectangular bar stock. Typical applications:
The square bore prevents rotation of the workpiece under cutting torque. Unlike a round bore collet with a set screw, the square geometry transmits torque directly through the collet body. This reduces wear on the collet and improves positional repeatability for cross-drilled or milled features.
Looking for a different part? We also machine Custom CNC Collet Chuck 3 Jaw Through Hole Auto Lathe | BQUQ Precision in the same Dongguan factory.
Q: Is there really no MOQ? A: Yes, no MOQ. We machine a single prototype collet to your drawing, or we run 5,000 pieces. The unit price drops with quantity, but the first article is always inspected the same way. Many buyers start with one piece to verify fit and concentricity on their actual spindle.
Q: What tolerance can you hold on the square bore? A: ±0.005 mm on the square width and corner radius. Concentricity between the bore and the taper is held to ≤0.01 mm TIR. If your drawing calls for tighter, we can discuss grinding processes, but ±0.005 mm is our standard for 20-type collets.
Q: How long until I get parts? A: 10-15 working days for standard spring steel or alloy steel. Stainless steel adds 5 days. If you need a rush order for a line-down situation, call us. We can sometimes split the batch and air-ship the first pieces.
Q: Do you provide material certificates? A: Yes, every batch ships with a mill certificate for the raw material and our own heat treatment report. We keep records for 10 years. If your customer requires full traceability, we can provide it in PDF or hard copy.
Stop adapting your design to a catalog collet. Send us your print and get a part that fits your spindle, your stock, and your tolerance.
Email your drawing to sc@bquq.com or message us on WhatsApp at +86 13713157787.
Precision manufacturing is not a promise. It is a verified dimension on an inspection report. That is what we ship.
| 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 |
