OpeningYour drawing defines the part. Our CNC machines cut it. Every collet chuck extension bar is verified for concentricity and taper angle before it leaves our Dongguan factory. We do not ship gues
Your drawing defines the part. Our CNC machines cut it. Every collet chuck extension bar is verified for concentricity and taper angle before it leaves our Dongguan factory. We do not ship guesswork.
We make custom CNC collet chuck bodies, extension bars, and long-reach variants from bar stock or your forging. Taper accuracy is held to AT3 or better. Surface finish down to Ra 0.4. Standard lead time is 15-20 days for machined parts. No MOQ applies—one piece or one thousand, same process control.
At a glance: Tolerance ±0.005 mm on critical diameters, runout ≤0.005 mm TIR, hardness 58-62 HRC (option), lead time 15-20 days, no MOQ, inspection report with every batch.
| Parameter | Value |
|---|---|
| Material | 20CrMnTi, 40Cr, 42CrMo, 65Mn, or per your spec |
| Material condition | Hardened and tempered, or case-hardened |
| Taper accuracy | AT3 or AT2 per ISO 15488 |
| Runout (TIR) | ≤0.005 mm at nose, ≤0.01 mm at 100 mm reach |
| Surface finish | Ra 0.4 – 0.8 µm on taper, Ra 1.6 on body |
| Hardness | 58-62 HRC (case), 28-32 HRC (core) |
| Thread class | 6H / 6g per ISO metric |
| Keyway / drive slots | Milled, ±0.02 mm width |
| Balancing | G2.5 optional for high-speed use |
| Process | CNC turning, CNC milling, internal grinding, lapping |
| Inspection | CMM, taper gauge, hardness tester, surface profilometer |
| Batch size | 1 to 10,000 pieces |
| Lead time | 15-20 days standard, 7 days for sample |
| Documentation | Material cert, inspection report, batch traceability |
We grind the internal taper after heat treatment. That is the only way to hold AT3. We do not grind from soft stock. If you need a longer reach, we machine the extension bar as one piece—no welded joints, no press-fit sleeves. One piece means predictable stiffness and no runout drift.
1. Batch-traceable quality. Every part gets a unique batch number. We record material heat number, machine operator, tool offsets, and inspection results. If a problem appears in your assembly line, we trace it to the exact batch and date. No ambiguity.
2. Inspection report per batch. You do not have to ask. Every shipment includes a dimensional report with actual measured values—not just a pass/fail stamp. Taper angle, runout, hardness, surface finish. We measure what matters for a collet chuck.
3. One factory for CNC + stamping + springs + heat sinks. Your collet chuck is not the only part you buy. We also make metal stampings, precision springs, and aluminum heat sinks under the same roof. One purchase order, one quality system, one shipping point. Fewer suppliers, fewer surprises.
Custom CNC collet chuck extension bars are not shelf items. They go into machines that need reach without sacrificing rigidity.
In every case, the buyer needs the same thing: a chuck that holds the tool straight, does not vibrate, and does not add runout. That is what we deliver.
Q: Do you really have no MOQ? A: Yes. We machine one prototype or a full production run. The per-piece price changes, but the process control does not. Many buyers start with one sample, test it, then order 500.
Q: What tolerance can you guarantee on the taper and runout? A: Taper angle to AT3 (or AT2 if you specify). Runout at the nose is ≤0.005 mm TIR. For long-reach bars, we hold ≤0.01 mm TIR at 100 mm from the nose. We verify every part on a CMM and a precision taper gauge.
Q: What is your standard lead time? A: 15-20 days for machined parts from stock. If you need a sample for fit testing, we can ship in 7 days. For high-volume orders with repeat orders, we can set up a blanket schedule.
Q: Can you provide material certificates and inspection reports? A: Yes. Every batch ships with a material certificate (EN 10204 3.1 or 3.2 if required) and a dimensional inspection report. We keep records for 10 years.
Send us your PDF or STEP file. We will check the taper, the reach, the material, and the thread. You will get a firm quote in 12 hours—price, lead time, and a clear statement of what we can hold.
Email: sc@bquq.com WhatsApp: +86 13713157787
Precision manufacturing, made in China, with no MOQ and no excuses. Your drawing is the only thing we need to start.
| 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 |
