What This 36 Type Collet Actually Does on Your Auto Lathe This is a CNC machined Auto Lathe 36 Type Collet With Pin Slot, built for high-speed Swiss-type and sliding-headstock lathes. It grips bar sto
This is a CNC machined Auto Lathe 36 Type Collet With Pin Slot, built for high-speed Swiss-type and sliding-headstock lathes. It grips bar stock from Ø3 mm to Ø36 mm with a concentricity runout of ≤0.005 mm TIR. That means your finished part roundness stays inside 5 microns, cycle after cycle. We hold the slot width and pin bore to ±0.003 mm, so the collet locks into your spindle nose without shimming or hand fitting. Made in China by BQUQ, 20 years of precision manufacturing, and we ship standard sizes in 7 working days.
Most collet failures start with rotation. The pin slot on this 36 type is not a cosmetic groove—it is a hardened locating feature. We mill the slot to a width of 4.0 mm ±0.005 mm and depth of 2.5 mm, matching the drive pin in your spindle. When the collet closes, the pin engages the slot flanks, not the slot bottom. This distributes torque evenly and eliminates the "jump" you get with round collets. The slot edges are deburred to 0.05 mm radius, so the pin slides in clean without catching on burrs. If your machine uses a different pin size, tell us the drawing—we will cut the slot to your spec.
We do not use free-cutting mild steel. The body is 20CrMnTi alloy steel, carburized to a case depth of 0.6–0.8 mm. Core hardness is 35–40 HRC for toughness; surface hardness is 58–62 HRC for wear resistance. The bore is ground after hardening, not before. That is the difference between a collet that lasts 6 months and one that lasts 2 weeks. We also offer a full-hard version in 9Cr18MoV stainless for corrosive coolant environments—same geometry, same tolerance. For spring-loaded variants, we use 65Mn spring steel, tempered to 44–48 HRC, with the slot cut after tempering to avoid distortion.
Runout is not a single operation—it is a sequence. We rough turn the OD, then heat treat, then grind the bore to Ø36.000 mm +0.005/-0.000. Next, we press the collet onto a precision mandrel (the mandrel itself is ground to 0.002 mm TIR) and grind the OD taper to 1°30' ±2'. The pin slot is cut last, using a wire EDM, so the slot does not distort the bore. Every collet is checked on a Marposs gauge station: bore diameter, taper angle, slot width, and TIR. We keep a Cpk of ≥1.33 on all critical dimensions. If you need a copy of the inspection report, it ships with the box—no extra charge.
Every single collet gets a full dimensional check, not a batch sample. We measure: bore diameter at three depths, slot width and depth, pin slot position relative to the bore axis, taper angle on a sine plate, and TIR on a 0.0001 mm indicator. Surface finish is verified with a Mitutoyo SJ-210 profilometer—Ra 0.4 µm on the bore, Ra 0.8 µm on the taper. Hardness is tested on a Rockwell C scale at two points on the OD. If any reading is out of spec, the collet is scrapped, not reworked. We also do a 100% visual check for edge break and surface defects under 5x magnification.
This collet follows the standard ER-36 and 36 type cross-reference dimensions. The taper angle is 1°30', the threaded pull-back section is M36 x 1.5, and the overall length is 60 mm. It fits machines from Citizen, Star, Tsugami, and most Chinese auto lathes that accept the 36 type. If your spindle uses a 35 mm or 38 mm pull-tube, the OD can be adjusted—just send your drawing. We keep 12 standard sizes in stock (Ø3, Ø4, Ø5, Ø6, Ø8, Ø10, Ø12, Ø14, Ø16, Ø20, Ø25, Ø32) for same-day dispatch. Non-standard bores (e.g., Ø7.5 mm) are machined in 3 days.
No MOQ. That is a standing policy for all BQUQ collets, not a promo. Standard sizes ship in 7 working days. Custom bore diameters with the same slot geometry ship in 10 working days. For a full custom collet (different material, different slot position, different taper), lead time is 15 working days after drawing approval. Price depends on material and quantity. For 1–10 pieces, unit price is around $18–$25. For 100+ pieces, price drops to $9–$12. We use CNC turning and grinding in-house, so there is no outsourcing markup. Freight is DHL or FedEx, door-to-door, 3–5 days to the US or EU.
| Specification | Value |
|---|---|
| Product Name | CNC Machined Auto Lathe 36 Type Collet With Pin Slot |
| Material | 20CrMnTi (carburized) or 9Cr18MoV stainless |
| Hardness (Surface) | 58–62 HRC (carburized case) |
| Hardness (Core) | 35–40 HRC |
| Bore Diameter Range | Ø3 mm to Ø36 mm (custom bore available) |
| Bore Tolerance | +0.005 mm / -0.000 mm |
| Slot Width Tolerance | ±0.003 mm |
| Concentricity (TIR) | ≤0.005 mm |
| Surface Finish (Bore) | Ra 0.4 µm |
| Surface Finish (Taper) | Ra 0.8 µm |
| Taper Angle | 1°30' ±2' |
| Overall Length | 60 mm |
| Lead Time (Standard) | 7 working days |
| MOQ | No MOQ (1 piece accepted) |
Yes, we can rotate the slot position to any angle (0°–360°) relative to the collet's orientation mark—just specify the degree on your drawing.
Yes, we offer TiN or TiAlN coating on the bore and taper, which raises surface hardness to 85 HRC equivalent and reduces friction—ideal for aluminum or brass without coolant.
We wire EDM the slot, then use a ceramic brush to break edges to a 0.05 mm radius, and inspect under 5x magnification—burrs are rejected, not shipped.
Yes, we ship single samples via DHL Express within 24 hours of confirmation—sample price is the same as unit price for 10 pieces, but the cost is refunded on your first bulk order.
Send us your part number, drawing, or just a photo of your current collet. We will confirm the bore size, slot position, and taper within 4 hours, and a firm quote with freight within 12 hours. For engineering questions about collet gripping force or material selection, read our CNC cutting tool selection guide and CNC machining tolerances guide. Email your drawing to sc@bquq.com or WhatsApp +86 13713157787. We reply in English, Chinese, or Spanish—no MOQ, no minimum order value, just precision manufacturing from Dongguan.
| 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 |
