What This Collet Does and Why It Matters for Your 52-Type Lathe This is a CNC Machined Auto Lathe 52 Type Round Bore Extended Collet. It grips round stock firmly in the spindle of a 52-type automatic
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What This Collet Does and Why It Matters for Your 52-Type Lathe This is a CNC Machined Auto Lathe 52 Type Round Bore Extended Collet. It grips round stock firmly in the spindle of a 52-type automatic
This is a CNC Machined Auto Lathe 52 Type Round Bore Extended Collet. It grips round stock firmly in the spindle of a 52-type automatic lathe, extending your reach without sacrificing accuracy. The concrete numbers: runout is held to 0.005 mm TIR, hardness is 58 HRC, and surface finish stays at Ra 0.4 µm. You get repeatable clamping force cycle after cycle, and we ship standard sizes in 7 days from our Dongguan factory.
The extended nose on this collet adds 25 mm of gripping depth compared to a standard 52-type collet. That extra length supports long bars and reduces deflection during heavy turning or threading. You can feed stock further out of the spindle, which means fewer passes and less vibration. For parts like shafts, pins, or valve stems, this extension directly cuts cycle time by up to 15% in our tests.
We start with AISI 4140 alloy steel. This grade gives a good balance of toughness and wear resistance. After CNC machining the bore and the slots, we harden the collet to 58 ± 1 HRC. Then we temper it to relieve stress, which prevents cracking during high-speed clamping. The final step is a black oxide finish on the outer body to resist rust and reduce friction against the spindle taper.
The round bore comes in standard diameters from 5 mm to 42 mm, in 0.5 mm increments. If your stock is metric or inch, we can machine the bore to your exact size with a tolerance of +0.005 / -0.000 mm. The internal surface is ground after hardening, not just turned, which is why we achieve Ra 0.4 µm. That smooth bore means less galling on soft materials like aluminum or brass.
Each collet is checked on a CNC coordinate measuring machine before packing. We measure the bore diameter at three depths, the taper angle, and the runout at the nose. Hardness is verified with a Rockwell tester on a test tab that is machined from the same bar as the collet. If any dimension is out of spec, the collet is scrapped, not reworked. You get a printed inspection report with every order.
Our factory has 20 years of experience in CNC machining and stamping. We run a bank of 20 CNC lathes dedicated to collet production, which lets us batch similar sizes together. That efficiency keeps our price per unit lower than European or Japanese alternatives. And because we are the manufacturer, not a trader, you talk directly to the engineers who make the parts. This is precision manufacturing made in China, but with German-style QC discipline.
This collet uses the standard 52-type taper with a 1:10 angle and an M55 x 2.0 pull-back thread. It fits most 52-type automatic lathes from brands like Citizen, Star, and Tsugami. The extended nose is solid, not split, which means the clamping force is applied only at the rear thread area. That design prevents the nose from flexing when you grip a long bar, keeping the workpiece concentric.
Standard bore sizes are stocked in our Dongguan warehouse and ship within 7 days. Custom bore sizes take 10 to 12 days because we need to machine and grind the bore after hardening. We have no MOQ — you can order a single piece for testing. Each collet is wrapped in anti-rust paper, placed in a foam insert, and boxed with the inspection report. Air freight to the US or Europe takes 3 to 5 days.
| Parameter | Value |
|---|---|
| Material | AISI 4140 alloy steel |
| Hardness | 58 ± 1 HRC |
| Bore diameter range | 5 mm to 42 mm (0.5 mm increments) |
| Bore tolerance | +0.005 / -0.000 mm |
| Runout (TIR at nose) | 0.005 mm |
| Surface finish (bore) | Ra 0.4 µm |
| Extension length | +25 mm vs standard 52-type |
| Taper angle | 1:10 (standard 52-type) |
| Pull-back thread | M55 x 2.0 |
| Lead time (standard) | 7 days |
| Lead time (custom bore) | 10-12 days |
| MOQ | No MOQ (1 piece accepted) |
There is no MOQ — order one piece to verify fit and runout on your own machine before committing to a larger batch.
Yes, we can machine any bore diameter between 5 mm and 42 mm, and we can extend the nose further than 25 mm, but the max extension is 40 mm to avoid bending under load.
We grind the bore and the taper in a single setup on the same machine, then we measure runout with a dial indicator while the collet is clamped in a master holder — this confirms the geometry is stable.
Custom bores take 12 days from drawing approval to shipment, because we harden first and then grind the bore to final tolerance, which adds two extra days compared to standard stock.
Send us your drawing or just the bore size and stock material you are running. Our engineers will reply within 12 hours with a firm quote, including the exact price per piece and the shipping cost. For quick reference, check our CNC cutting tool selection guide to verify your tooling setup, and review the CNC machining tolerances guide to align your print callouts with our capabilities.
Email your RFQ to sc@bquq.com or send a WhatsApp message to +86 13713157787. Attach your drawing in PDF or STEP format. We will confirm the bore tolerance, the coating option (black oxide or plain), and the quantity. You will have a firm price and a delivery date within 12 hours, Monday to Saturday, China time.
| 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 |
