What This Collet Chuck Does and Why the 0.005 mm Runout Matters This is a CNC machined auto lathe 700 type round bore spring collet chuck, built for high-speed turning and Swiss-type automatic lathes
Get a quote
-
English
- sc@bquq.com
What This Collet Chuck Does and Why the 0.005 mm Runout Matters This is a CNC machined auto lathe 700 type round bore spring collet chuck, built for high-speed turning and Swiss-type automatic lathes
This is a CNC machined auto lathe 700 type round bore spring collet chuck, built for high-speed turning and Swiss-type automatic lathes. It grips round stock from 3 mm to 42 mm with a guaranteed concentricity of 0.005 mm TIR (total indicated reading) at the nose. That means your machined parts come off the spindle with consistent wall thickness, no taper, and no chatter marks—even at 6,000 RPM. We harden the gripping surface to 58–60 HRC, so you get 3x longer wear life than standard 45 HRC chucks. Every unit is made in China at our Dongguan factory, and we ship standard sizes in 7 days with no MOQ.
The 700 series uses a full-length round bore with a single axial slot, not a segmented collet. This design distributes clamping force evenly around 360 degrees of the workpiece. You avoid the three-point pinch marks you get with ER or TG collets. The spring temper in the bore—heat-treated to 58 HRC—allows the collet to close 0.5 mm radially and still spring back to its exact original diameter. We grind the bore after heat treatment, not before, so the roundness holds within 0.002 mm even after thousands of open-close cycles. For bar stock feeding, the round bore self-centers the material as it advances, reducing vibration and extending your insert life.
We start with either 8620 alloy steel or 65Mn spring steel, depending on your application. For general turning, 8620 gives you a tough core with a hard, wear-resistant case after carburizing. For high-cycle spring applications—over 100,000 open-close actions—we use 65Mn, which offers superior fatigue resistance. Both materials go through a three-step heat treatment: quench, temper, and cryogenic stabilization. The cryogenic step is key. It converts retained austenite to martensite, which prevents the bore from growing or distorting during your production run. Final hardness is 58–60 HRC on the gripping surface, 48–52 HRC on the body. We finish with a black oxide coating that resists rust and reduces friction when the collet slides in the chuck body.
Every single collet chuck goes through a 12-point inspection before it leaves our floor. We measure the bore diameter with an air gauge to 0.001 mm resolution. We check concentricity between the bore and the taper using a precision mandrel and a dial indicator—the max runout at the nose is 0.005 mm, and we reject anything above that. Hardness is verified on a Rockwell tester at three points: the nose, the middle, and the tail. We also test the spring-back force by compressing the bore 0.5 mm and measuring the return to zero. Each part gets a serial number, and we keep the inspection data on file for 10 years. If you get a bad part, we replace it within 48 hours—but in the last five years, our rejection rate is 0.3%.
Below is the dimensional and performance data for our standard line. Custom bore diameters, slot widths, and taper angles are available—just send your drawing.
| Parameter | Value |
|---|---|
| Bore diameter range | 3 mm – 42 mm (in 0.5 mm increments) |
| Collet body OD | 42 mm (700 type standard) |
| Total length | 80 mm / 100 mm (optional) |
| Taper angle | 16° included (custom 20° available) |
| Material | 8620 alloy steel or 65Mn spring steel |
| Hardness (gripping surface) | 58–60 HRC |
| Hardness (body) | 48–52 HRC |
| Concentricity (TIR at nose) | 0.005 mm |
| Bore roundness | 0.002 mm |
| Surface finish (bore) | Ra 0.4 µm |
| Max clamping force | 12 kN (at 6 bar hydraulic) |
| Max spindle speed | 6,000 RPM |
| Lead time (standard) | 7 days |
| MOQ | No MOQ (single piece accepted) |
The 700 type is a universal standard for Japanese and European auto lathes, including Citizen, Star, Tsugami, and Tornos. The external taper matches the spindle nose, so you don’t need a custom adapter. The round bore accepts ground bar stock directly—no need for a feed finger or guide bushing. We machine the back face flat to 0.005 mm, which ensures the collet seats square against the spindle face. If you are using a hydraulic or pneumatic actuator, the chuck body has a standard thread pattern (M20 x 1.5) for the draw tube. For existing machines with a worn spindle, we can regrind the taper to match your actual spindle angle—just send us a print or a sample of your current chuck.
Standard sizes (3 mm to 42 mm in 0.5 mm steps) are stocked and ship in 7 days. For non-standard bores—like 4.2 mm or 17.8 mm—we machine them to your exact dimension in 10 days. The process is simple: send your drawing or just state the bore diameter and workpiece tolerance. We will recommend the correct slot width (standard 1.5 mm, but we can go down to 0.8 mm for small bores) and spring temper. We also offer a drawbar thread customization at no extra cost if you order more than 10 pieces. For prototyping, we accept a single piece order—no MOQ, no tooling fee. Just email the drawing and we will confirm the price and lead time within 12 hours.
There is no MOQ—you can order a single piece for prototyping or a full set of 20 different sizes for your machine shop.
Yes, we machine any bore from 3 mm to 42 mm in 0.1 mm increments, and we also adjust slot width and taper angle per your drawing.
We grind the bore and taper in a single clamping setup on a 5-axis CNC, and every unit is individually inspected with an air gauge and dial indicator before shipment.
Standard sizes ship in 7 days, custom bores in 10 days, and bulk orders (over 50 pieces) in 15 days—all from our Dongguan factory.
Stop guessing on tolerances and lead times. Send us your part drawing or your spindle specifications, and we will confirm the exact price, bore size, and ship date within 12 hours. We are a precision manufacturing company with 20 years of CNC machining experience, and we back every collet chuck with a 100% inspection report. For more on how to match your tooling, read our CNC cutting tool selection guide. If you need to set your own tolerances, check the CNC machining tolerances guide.
Email us your drawing at sc@bquq.com or message us on WhatsApp at +86 13713157787. We will respond with a firm quote, not a range. All our collet chucks are made in China under strict ISO 9001 control, and we ship worldwide via DHL or FedEx.
| 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 |
