This is our CNC machined 5C collet for round workpieces, built for lathes, grinders, and indexing fixtures. You get 0.005 mm total indicated runout (TIR) at the nose, repeatability of 0.003 mm, and a
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This is our CNC machined 5C collet for round workpieces, built for lathes, grinders, and indexing fixtures. You get 0.005 mm total indicated runout (TIR) at the nose, repeatability of 0.003 mm, and a
This is our CNC machined 5C collet for round workpieces, built for lathes, grinders, and indexing fixtures. You get 0.005 mm total indicated runout (TIR) at the nose, repeatability of 0.003 mm, and a hardness of 58-62 HRC across the gripping surface. Standard lead time is 7-10 days for catalog sizes, and we ship from our Dongguan factory with full inspection reports.
Spring collets flex and lose grip when bar diameter varies by more than 0.05 mm. Our 5C collets use a hardened steel body with a precision ground slot pattern, so the gripping force stays within ±5% across the full clamping range. For a 25.4 mm bore, that means you can feed bars from 25.35 to 25.45 mm without adjusting the chuck. TIR stays below 0.005 mm, which is 3x tighter than standard ER collets.
We machine every collet from 8620 alloy steel or 9Cr18 stainless, depending on your coolant and part material. For general lathe work, 8620 is carburized to 0.8-1.2 mm case depth, then hardened to 58-62 HRC. For corrosive environments, 9Cr18 is through-hardened to 56-60 HRC. Both materials get a cryogenic treatment at -80°C to stabilize dimensions, so the collet does not grow or shrink after 100,000 cycles.
Runout is not just about the bore. It starts with the 5C taper angle—we grind the 20-degree included angle to ±0.0005 degrees. Then we grind the OD and the bore in a single setup on a CNC cylindrical grinder, using live centers with less than 0.002 mm runout. The final honing pass removes any grinding burn and leaves a cross-hatch pattern that holds coolant for better chip evacuation. Every collet is then tested on a 5C master mandrel with a dial indicator; we reject anything above 0.005 mm at the nose.
| Parameter | Value | Notes |
|---|---|---|
| Available bore sizes | 3.0 - 26.0 mm (1/8" - 1-1/32") | In 0.5 mm and 1/64" increments |
| Gripping range per collet | +0.05 / -0.05 mm | From nominal bore |
| Material | 8620 alloy steel or 9Cr18 stainless | Customer choice, no extra cost |
| Hardness after treatment | 58-62 HRC (8620), 56-60 HRC (9Cr18) | Case depth 0.8-1.2 mm |
| Runout TIR at nose | ≤ 0.005 mm | Tested on master mandrel |
| Repeatability | ≤ 0.003 mm | Same collet, same bar |
| Surface finish (bore & OD) | Ra 0.4 μm | Grinding + honing |
| Slot geometry | 3-slot or 6-slot design | 6-slot for thin walls above 20 mm |
| Lead time (standard sizes) | 7-10 working days | Custom bores 12-15 days |
| MOQ | No MOQ | Single piece accepted |
You need a 12.7 mm bore with a hex step for a valve stem? We machine custom profiles directly on our CNC lathes—no dedicated tooling, no setup fee. Send a drawing or a sketch with your nominal diameter, tolerance class, and gripping length. We will quote the same day and ship a single prototype in 8-10 days. For production runs, we hold your custom collet specification on file and re-order with a part number, so repeat orders ship in 5 days.
Each collet gets a dimensional report with three data points: bore diameter at front, middle, and rear, measured with an air gauge. We also test runout on a 5C spindle adapter and record the max TIR. The report includes hardness test values (Rockwell C scale) and surface finish Ra measurement. If you need a full material certificate (EN 10204 3.1), we provide it at no extra charge—just note it on your PO.
Every collet is laser-marked with the bore size, batch number, and our BQUQ logo. We pack in individual plastic tubes with foam caps, then box them in corrugated cartons. For high-volume orders, we offer a tray system with labeled slots for 20 collets, so your tool crib can restock without removing each collet from its sleeve. We do not use loose paper or cloth that can leave fibers in a clean machining area.
We ship from Dongguan via DHL, FedEx, or UPS—your choice. For a 1 kg box of collets, DHL Express delivers in 3-5 days to the US, EU, or Southeast Asia. We handle all export documentation, including commercial invoice and packing list. If you are in a tariff zone, we can provide the correct HS code (8466.20) and country of origin certificate. For bulk orders (over 100 pieces), we offer sea freight with full container or LCL options, which cuts cost by 40% compared to air.
We have no MOQ—you can order one custom collet for a prototype and scale up later without re-engineering.
Yes, we machine any round bore from 3 to 26 mm in 0.01 mm increments; tolerance can be held to H6 or your specified class.
We mount each collet on a precision 5C master mandrel, spin it at 300 RPM, and measure TIR with a 0.001 mm resolution dial indicator at the nose and 25 mm back.
For standard bores, 7 working days; for custom bores, 12 working days from drawing approval—shipping time is extra.
Send your drawing, bore size, tolerance, and quantity to sc@bquq.com or WhatsApp +86 13713157787. We reply with a firm price, lead time, and a suggested material if you are unsure. For design tips on tool selection, read our CNC cutting tool selection guide. If you are optimizing your lathe cycle, check our advanced toolpath strategies article. For general tolerance callouts, see our CNC machining tolerances guide. This is precision manufacturing made in China with no MOQ—our factory has 20 years of experience, and we guarantee every collet meets the numbers above.
| 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 |
