Why This HSK63A ER Chuck Delivers 0.005 mm TIR on Your Spindle This is a CNC machined HSK63A ER collet chuck tool holder built for one job: holding your cutting tool rigidly so the edge stays exactly
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Why This HSK63A ER Chuck Delivers 0.005 mm TIR on Your Spindle This is a CNC machined HSK63A ER collet chuck tool holder built for one job: holding your cutting tool rigidly so the edge stays exactly
This is a CNC machined HSK63A ER collet chuck tool holder built for one job: holding your cutting tool rigidly so the edge stays exactly where the CAM path says it should be. We machine the taper and the collet pocket in the same setup on a 5-axis Mazak, which holds the total indicated runout (TIR) at the nose to ≤ 0.005 mm. The body is hardened to 58–62 HRC, ground to Ra 0.4 µm on the critical diameters, and we ship standard sizes in 7 days. For a 20-year-old Dongguan precision manufacturing shop, this is routine work, not a special project.
The HSK63A shank is not a steep taper like BT or CAT. It uses a 1/10 hollow taper that pulls tight against the spindle face with two points of contact. That dual-contact design gives you higher bending stiffness and better repeatability at 10,000+ RPM. Our chuck mates that shank to an ER collet pocket machined to a 8° included angle. The ER collet collapses evenly when you torque the nut, gripping the tool shank on three lines of contact. We grind the pocket after heat treatment, so the collet seats without wobble. If your spindle runs above 15,000 RPM, ask us about the G2.5 balance option—we can balance to 25 g·mm or better.
We start with 8620 alloy steel for the body, not cheap 4140. The HSK taper and the ER pocket need case hardness for wear resistance, but the core must stay tough to absorb vibration. We carburize the blank to a case depth of 0.8–1.2 mm, then harden and temper to 58–62 HRC. After that, we grind the taper and the pocket. The thread on the nut is a separate part—we use 40CrMo and nitriding to 65 HRC surface hardness so the threads don’t gall after 500+ tool changes. The ER collet itself is not ours—you supply it or we source a brand you specify. The chuck body, nut, and retaining screw are all made in China by our own precision manufacturing line.
No chuck leaves our Dongguan floor without a full inspection report. We check the HSK taper with a CMM against the DIN 69893 standard—that means the taper angle is within AT3 tolerance. We mount the chuck on a test mandrel and measure TIR at 3 positions: at the nose, 50 mm out, and 100 mm out. The reading must be ≤ 0.005 mm, 0.008 mm, and 0.012 mm respectively. We measure the surface finish on the taper with a profilometer—target Ra 0.4 µm. For balanced units, we run a G2.5 balance test at 20,000 RPM on a Schenck machine. Each unit gets a serial number laser-marked on the flange, and the report is PDF-signed.
| Parameter | Value / Range |
|---|---|
| Shank type | HSK63A (DIN 69893) |
| Collet type | ER16, ER20, ER25, ER32, ER40 |
| Clamping range | 1.0 – 26.0 mm (depends on ER size) |
| Body material | 8620 alloy steel, carburized |
| Hardness (body) | 58 – 62 HRC |
| Hardness (nut threads) | ≥ 65 HRC (nitrided) |
| TIR at nose | ≤ 0.005 mm |
| TIR at 100 mm | ≤ 0.012 mm |
| Surface finish (taper) | Ra 0.4 µm |
| Balance option | G2.5 @ 20,000 RPM (25 g·mm) |
| Lead time (standard) | 7 days |
| MOQ | No MOQ (single piece accepted) |
| Country of origin | Made in China (Dongguan) |
You can have a perfect 0.005 mm TIR chuck, but if you tighten the nut with a wrench instead of a torque wrench, the collet shifts. We machine a torque spec into the nut body—use it. For ER32, that is 90–110 N·m. For ER16, it is 35–45 N·m. Over-torquing distorts the collet pocket. Second, if your spindle runs above 12,000 RPM, order the balanced version. Unbalanced chucks create synchronous vibration that wrecks surface finish and kills spindle bearings. Our standard chuck is balanced to G6.3; the option is G2.5. For high-speed milling of aluminum or graphite, this is not optional.
To get an accurate quote, send us three numbers: the ER size, the tool shank diameter, and the projection length from the spindle face. If you need a specific nut type (e.g., slim nut for deep pockets), say so. If you need a through-coolant version, we drill the center hole to 5 mm or 7 mm depending on ER size. If you need a retention knob or a different thread on the pull stud, tell us the exact drawing number. We also make non-standard projection lengths—that is the beauty of CNC machining. We charge the same for a custom length as for a standard one up to 150 mm total length. Beyond that, we add 2–3 days to the lead time.
Zero—we accept single-piece orders for any HSK63A ER collet chuck, and the price reflects the setup cost, not a volume discount.
Yes, any projection length from 50 mm to 150 mm is standard, and we drill axial coolant holes up to 7 mm on any ER size.
We use a CMM for the HSK taper geometry and a test mandrel with a 0.001 mm dial indicator to verify TIR at the nose and at 100 mm.
Standard 7 days, 9 days with G2.5 balancing; for rush orders with 100+ pieces, we can compress to 5 days.
Stop guessing whether a cheap holder will pass your inspection. Send us your drawing or a simple sketch with the ER size and projection length. We will reply within 12 hours with a firm price, a lead time, and a DFM note if your drawing has any potential issues. For a quick reference on cutting tool selection, read our CNC cutting tool selection guide, and for tolerance stacking questions, check our CNC machining tolerances guide. Email us at sc@bquq.com or send a WhatsApp message to +86 13713157787. We ship worldwide via DHL or FedEx, and every unit is made in China with a full inspection report.
| 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 |
