What This Collet Collection Delivers: Tight Grip, Zero Runout, Fast Ship This is our complete CNC machined auto lathe collet full range collection — ER8 through ER50, plus 5C, R8, and custom auto lath
This is our complete CNC machined auto lathe collet full range collection — ER8 through ER50, plus 5C, R8, and custom auto lathe collets. Every unit is ground to a runout of ≤0.005 mm TIR at the nose, hardened to 58-62 HRC, and surface finished to Ra 0.4 µm. Standard sizes ship in 15 days; custom profiles in 20 days. No MOQ — order one piece or a thousand.
An ER collet grips the tool shank along its full tapered length, not just at three points. This distributes clamping force evenly, eliminating the wobble common in jaw chucks. Our auto lathe collets are slotted precisely — 8 slots for ER11 and smaller, 12 slots for ER16 and above — so the collet closes concentrically. The result: you can run at 20,000 RPM without vibration, and your tool life extends by up to 30% compared to standard chucks.
We machine all collets from AISI 8620 alloy steel. After CNC turning and milling, we through-harden to 58-62 HRC, then temper for dimensional stability. Case-hardened collets wear out fast — we don't use them. For corrosion-resistant applications, we offer 17-4 PH stainless steel at 45-50 HRC. Each collet is ID ground after heat treatment to hold bore tolerance to +0.005/-0.000 mm. This is precision manufacturing made in China, but to ISO 9001 standards, not "good enough" standards.
Our collection covers every standard size you'll need for CNC lathes and milling machines:
| Specification | Detail |
|---|---|
| Collet Series | ER8, ER11, ER16, ER20, ER25, ER32, ER40, ER50, 5C, R8 |
| Clamping Range | Ø1.0 mm to Ø34.0 mm (ER50); Ø1.0 mm to Ø26.0 mm (ER40) |
| Material | AISI 8620 alloy steel (standard); 17-4 PH stainless (optional) |
| Hardness | 58-62 HRC (through-hardened) |
| Runout (TIR) | ≤0.005 mm at nose, ≤0.010 mm at 4× diameter from nose |
| Bore Tolerance | +0.005 / -0.000 mm |
| Surface Finish | Ra 0.4 µm (ground), Ra 0.8 µm (turned) |
| Grip Torque | Up to 90 Nm at ER40 with standard nut |
| Lead Time | 15 days standard, 20 days custom (CNC machined) |
| MOQ | No MOQ — single piece accepted |
We don't spot-check. Every collet in this full range collection is inspected individually. First, we measure bore diameter with an air gauge to 0.001 mm resolution. Then we mount the collet in a test holder and check runout with a dial indicator at the nose and at 25 mm from the nose. Finally, we verify slot geometry and taper angle (8° for ER series) on an optical comparator. A signed inspection report ships with each order. If a collet fails any check, it's scrapped, not reworked.
Standard collets grip round stock. But your part might be hex, square, or an irregular profile. Send us your drawing and we'll CNC machine a custom collet profile to match your part exactly. We hold the same tolerance — ≤0.005 mm runout — and the same hardness. Lead time is 20 days for custom profiles. We've made collets for Swiss-type lathes, sliding head machines, and multi-spindle automatics. No tooling charge for profiles under 50 mm diameter.
Before you order, check three things on your machine: the collet taper angle (ER standard is 8°), the thread size on your drawbar or nut (e.g., M12 for ER16, M16 for ER25), and the maximum bar diameter you'll feed. If you're unsure, our engineers will help you match — just send your spindle drawing or machine model. This is the same logic we explain in our CNC cutting tool selection guide, where we break down collet vs. chuck decisions. For tolerance limits on the parts you'll make with these collets, check our CNC machining tolerances guide.
We are BQUQ, a 20-year-old factory in Dongguan, China. We machine, stamp, and grind in-house — no trading company middleman. This means you get factory pricing (typically 20-30% lower than distributor prices), direct engineering support, and full traceability of material certificates. Our collets are used by automotive, aerospace, and medical device manufacturers worldwide. And because we're the factory, we can adapt any collet to your machine without minimum order constraints.
No MOQ — we accept orders for a single collet, though pricing improves slightly at 10+ pieces per size.
Yes, send your drawing or sample; we CNC machine custom profiles (hex, square, spline) within 20 days and hold the same ≤0.005 mm runout.
We use SPC (statistical process control) on every batch — hardness is tested on 5% of units, and 100% of units go through air gauge bore measurement.
Standard ER collets ship in 15 days from order confirmation; custom profiles ship in 20 days; express air freight is available for urgent orders.
Stop guessing if a collet fits. Send us your spindle drawing, part profile, or just your machine model. We'll reply with a firm quote — price, lead time, and recommended collet size — within 12 business hours. Email your drawing to sc@bquq.com or message us on WhatsApp at +86 13713157787. For standard sizes, you can also order directly from this full range collection — no drawing needed, just the ER number and bore size.
| 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 |
