This is a CNC Machined BT30 ER Collet Chuck Tool Holder for CNC Spindle, built to grip ER collets with a guaranteed runout of 0.005mm TIR at the nose. You get a hardened steel body at HRC 58-62, a sur
This is a CNC Machined BT30 ER Collet Chuck Tool Holder for CNC Spindle, built to grip ER collets with a guaranteed runout of 0.005mm TIR at the nose. You get a hardened steel body at HRC 58-62, a surface finish of Ra 0.4, and a standard lead time of 7 working days. It is precision manufacturing made in China, with no MOQ—order one piece or a thousand.
The BT30 taper is ground to AT3 grade, which means the contact area with your spindle is at least 90%—no rocking, no vibration. Inside, the ER collet seat is machined to a concentricity of 0.003mm relative to the taper. When you tighten the nut, the collet compresses evenly around the tool shank, not just at two points. This design eliminates the runout that ordinary chucks show at 3xD overhang. You can run end mills at 12,000 RPM with a 0.005mm TIR, which extends tool life by 30% compared to standard holders.
We start with 20CrMnTi alloy steel, not cheap 45# carbon steel. The blank is forged, then annealed to relieve internal stress. After CNC machining, we carburize the surface to a depth of 0.8-1.2mm. The core stays tough at HRC 35-40, while the surface reaches HRC 58-62. This combination prevents the taper from deforming under heavy cutting loads. The nut is made from 40Cr, hardened to HRC 40-45, and the threads are rolled—not cut—for a smoother finish and higher fatigue strength.
Every single unit goes through a 5-step inspection. First, the BT30 taper is checked on a CMM against a master gauge—AT3 tolerance means 0.005mm over the full taper length. Second, the ER collet bore is measured for roundness within 0.002mm. Third, we assemble the chuck with a precision test bar and measure runout at the nose: maximum 0.005mm TIR. Fourth, surface finish is verified with a profilometer: Ra 0.4 on the taper, Ra 0.8 on the body. Fifth, we test the nut torque—it must click at 70-80 Nm, no more, no less. A full inspection report is shipped with each order.
The BT30 taper follows JIS B6339, with a 30mm large end diameter and a 1:29.4 taper ratio. Pull stud threads are M12, and we supply the pull stud as standard—either MAS BT or DIN 69872 style. The overall length is 105mm for ER32 and 120mm for ER40 versions. This holder fits any spindle with a standard BT30 interface, including Brother, Fanuc, Mazak, and Haas machines that use a BT30 spindle. If your spindle uses a different pull stud length, tell us, and we will adjust the thread depth for free.
We offer this holder in ER16, ER20, ER25, ER32, and ER40 collet sizes. The grip range for each is standard: ER32 clamps 2mm to 20mm, ER40 clamps 3mm to 26mm. The collet nut has a slotted drive face that transfers torque directly to the collet, reducing slippage at high feed rates. For heavy roughing, we recommend the ER32 version with a 20mm shank—it has a 45% larger contact area than an ER25. For finishing, use the ER16 version with a 6mm shank to keep runout below 0.003mm.
The standard finish is black oxide, which provides a 0.005mm dimensional change—not enough to affect the taper fit. If you need better corrosion resistance or lower friction, we offer electroless nickel plating at Ra 0.2 and a TiN coating that reduces chip welding by 60%. For high-speed machining above 15,000 RPM, choose the TiAlN-coated version—it withstands 800°C cutting temperatures without losing hardness. The coating is applied after final grinding, so the taper geometry is not altered.
Standard lead time is 7 working days for quantities up to 200 pieces. For larger orders—up to 1,000 pieces—we need 15 working days. Every holder is individually wrapped in anti-rust paper, then placed in a foam-lined plastic box, then packed in a 5-layer corrugated carton. For sea freight, we add a moisture-absorbing desiccant bag and a vacuum-sealed outer layer. You will not find rust or scratches when you open the box, even after 30 days in transit.
There is no MOQ—we accept single-piece orders for prototyping and sample testing, and you can order just one to verify the fit on your spindle.
Yes, we can adjust the pull stud thread depth, change the nut style (e.g., with or without a bearing), or add a through-coolant hole—just send your drawing or specify the modification in your inquiry.
Every batch is sampled at 5% with full dimensional checks, and 100% of units are tested for runout and taper contact before packing—plus, you receive a copy of the inspection report with each shipment.
For 500 pieces, we can deliver in 10 working days using our priority production line—this includes material procurement, machining, heat treatment, and final inspection.
Before you finalize your tooling setup, check our CNC cutting tool selection guide to match this holder with the right end mill. Also read our CNC machining tolerances guide to understand how runout affects your finished part dimensions.
Send your drawing or just the ER collet size and tool shank diameter. We will reply with a firm quote within 12 hours, including freight costs and a delivery date. Email sc@bquq.com or WhatsApp +86 13713157787. No MOQ, no minimum order value—just precision manufacturing made in China, ready to ship.
| 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 |
