This is a CNC machined auto lathe 52 Type collet with a front-view hexagonal bore, built for sliding-head and fixed-head automatic lathes that use the 52 series spindle nose. The hex bore grips hexag
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This is a CNC machined auto lathe 52 Type collet with a front-view hexagonal bore, built for sliding-head and fixed-head automatic lathes that use the 52 series spindle nose. The hex bore grips hexag
This is a CNC machined auto lathe 52 Type collet with a front-view hexagonal bore, built for sliding-head and fixed-head automatic lathes that use the 52 series spindle nose. The hex bore grips hexagonal bar stock and hex-shaped tool shanks without crushing corners, and we hold the bore tolerance to +0.005/-0.000 mm with a total indicated runout (TIR) of 0.005 mm or less. You get a collet that repeats within 0.003 mm across 10,000 cycles, and our standard lead time is 7 business days for any quantity—including a single piece.
A round bore collet only touches the six corners of a hex bar, which deforms the material under clamping force and causes vibration during high-speed turning. Our front-view hex bore matches the full flank of each hex face, distributing clamping pressure evenly across 120° arcs. This reduces workpiece deflection by up to 40% compared to a round bore at the same clamping torque, and it eliminates marring on finished hex surfaces. For hex sizes from 3 mm to 32 mm across flats (AF), we cut the bore with a single-pass wire EDM then finish with a carbide reamer, giving you a true geometric hex with no corner radius over 0.05 mm.
The 52 Type collet follows the DIN 6341 / ISO 15488-B standard for the 52 mm spindle nose, which is common on Citizen, Star, Tsugami, and Hanwha sliding-head lathes. Our collet body is 52 mm OD, 34 mm long, with a 1:10 taper angle on the seating face—matching the original manufacturer’s geometry so you can drop it into your existing chuck without re-tuning. The front-view hex bore is concentric to the taper within 0.005 mm TIR, verified on a Zeiss CMM before shipment. We also offer the same collet with a rear pilot bore of 20 mm or 25 mm, depending on your bar feeder setup, and we can add an internal thread (M16x1.5 or M20x1.5) for a pull-back mechanism.
| Specification | Value |
|---|---|
| Material (body) | SAE 8620 case-hardened steel or 17-4PH stainless (option) |
| Hardness (effective case depth) | 58–60 HRC, case depth 0.8–1.2 mm |
| Hex bore size range | 3 mm to 32 mm across flats (AF), custom on request |
| Bore tolerance | +0.005 / -0.000 mm |
| Total indicated runout (TIR) | ≤ 0.005 mm at bore and taper |
| Surface finish (bore) | Ra 0.4 µm (mirror polish on request) |
| Taper angle | 1:10 (seating face), ground to 0.002 mm per 100 mm |
| Body OD / length | 52 mm / 34 mm |
| Repeatability (10,000 cycles) | ≤ 0.003 mm |
| Lead time | 7 business days (standard), 3 days (express) |
| MOQ | No MOQ — single piece accepted |
We start with SAE 8620 alloy steel (case-hardening grade) because it gives a tough core that resists bending under heavy clamping force, while the case-hardened surface reaches 58–60 HRC. The case depth is 0.8–1.2 mm, which is enough to withstand repeated opening and closing cycles without spalling. For corrosive coolants or food-grade applications, we offer 17-4PH stainless hardened to 44–48 HRC—slightly softer but fully rust-proof. Every collet is through-hardened in a vacuum furnace (no decarb layer), then deep-frozen at -80°C for 2 hours to stabilize the microstructure, which prevents dimensional drift over time.
We cut the hex bore in three steps. First, we turn the collet body on a CNC lathe and grind the 1:10 taper to final size. Second, we wire-EDM the hex shape from solid, leaving 0.2 mm stock on each flank. Third, we finish with a carbide form reamer on a jig grinder, holding the flank-to-flank tolerance at +0.005 mm. The EDM step avoids the cutting forces of a broach, which can push the thin wall (minimum 3 mm) out of round. After reaming, we deburr both front and back edges with a 0.1 mm chamfer, so hex bar stock slides in without catching. We also laser-engrave the hex size and date code on the OD—no ink that washes off.
Each collet goes through a 5-point inspection with a Zeiss CONTURA CMM. We measure the hex bore’s three pairs of opposite flanks (flatness and parallelism within 0.003 mm), the taper’s angle and straightness, the TIR between bore and taper, and the surface roughness with a Mitutoyo SJ-210. The CMM report is included in every shipment—even for a single-piece order. We also run a functional test: we clamp a matching hex bar at 30 N·m torque and measure the pull-back force on a load cell; the collet must hold the bar without slippage for 5 minutes. If any value is out of spec, we scrap the part, no rework.
This collet is designed for 52 Type auto lathes with a spindle speed up to 8,000 RPM. At that speed, the hex bore’s radial runout stays under 0.008 mm due to the balanced body (we dynamically balance to G2.5 grade). Do not use it for round stock—the hex corners will mark round bar and reduce clamping area by 30%. For round stock, order our standard round bore collet (same body, same taper). The max clamping force is 12 kN; exceeding that will deform the collet’s fingers permanently. For hex bars with sharp corners (less than 0.1 mm corner radius), we recommend a 0.2 mm corner relief on the bore—tell us and we’ll add it at no extra cost.
We have reverse-engineered the 52 Type collet to match the exact taper and bore depth of these machines: Citizen L20/L32, Star SR-20/SR-32, Tsugami B020/B032, Hanwha XD20/XD32, and Tornos MultiSwiss. If you have a different brand, send us a worn sample or a drawing—we will measure it and match the profile. The collet also works in standard ER-32 collet chucks if you use a 52-to-ER32 adapter sleeve, but the grip length is shorter (12 mm vs 20 mm), so we recommend the native 52 Type chuck for best rigidity.
No MOQ—we ship one collet or one thousand, with the same 7-day lead time and the same CMM inspection report.
Yes, we machine any hex size from 3 to 32 mm AF, and we can also make a square bore, a triangular bore, or a hex with a larger corner radius for soft materials—just send a sketch or a DXF file.
Every collet, prototype or production, is 100% inspected on the CMM and the report is sent with the part; we do not use sampling or skip-lot inspection.
Standard is 7 business days, but for an urgent line-down situation we can deliver a single collet in 3 business days by air express—just mark it “RUSH” in your email subject.
This collet is a direct result of our precision manufacturing capabilities in Dongguan, where we run 20 CNC lathes and 5 wire EDM machines. We are a made in China factory with 20 years of experience producing collets, springs, and heat sinks for automotive and medical customers. Before you finalize your design, check our CNC cutting tool selection guide to confirm the hex bore geometry and our CNC machining tolerances guide to understand how we hold +0.005 mm on a hardened part.
Send us your drawing or a worn sample for a firm quote within 12 hours—no design fees, no MOQ. Email sc@bquq.com or WhatsApp +86 13713157787. If you need a different hex size, a different material, or a special relief, include that in your first message and we will quote the exact machining 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 |
