What This ER Collet Chuck Kit Delivers in Real Numbers This is a complete CNC machined ER collet chuck tool kit designed to hold reamer, tap, drill, and endmill tooling with a guaranteed runout of 0.0
This is a complete CNC machined ER collet chuck tool kit designed to hold reamer, tap, drill, and endmill tooling with a guaranteed runout of 0.005 mm TIR at the nose. Each chuck body is hardened to HRC 58-62, surface finished to Ra 0.4 µm, and shipped from our Dongguan factory within 15 days. You get a ready-to-mount toolholding system that eliminates tool chatter, improves hole finish, and extends cutting tool life — without paying a premium for brand-name equivalents.
ER collet chucks work by compressing a slotted collet evenly around the tool shank using a locking nut. The 8-degree cone angle in the chuck body and collet creates a self-centering radial force. Our chucks are machined from a single billet of 42CrMo alloy steel, then precision ground on the taper and bore to achieve a concentricity of 0.005 mm. This means when you clamp a 10 mm endmill, the cutting edge stays within 5 microns of the spindle axis — critical for reaming and tap finishing where tolerance stack-up kills parts.
We start with 42CrMo steel (AISI 4140 equivalent) for the chuck body and nut. The body is hardened to HRC 58-62, while the nut is nitrided to HRC 60-64 for wear resistance. Collets are made from 65Mn spring steel, hardened to HRC 44-48, and slotted with EDM wire cutting to ensure uniform deflection. This combination gives you a chuck that survives thousands of clamping cycles without losing grip force or dimensional accuracy. We do not use cast blanks or welded assemblies — every unit is CNC machined from solid bar stock.
The standard kit includes one ER32 chuck body with a BT40 or CAT40 taper (other tapers available), one locking nut, and 10 collets ranging from 1 mm to 20 mm. This covers reamer shanks from 1 mm to 16 mm, tap shanks up to 14 mm, drill bits up to 20 mm, and endmill shanks up to 20 mm. Each collet is marked with its size range in 0.5 mm steps. We also offer ER16 and ER25 kits for lighter duty applications. All kit components are matched and tested together before shipment, so you do not need to source collets separately.
Every chuck body is checked on a CMM (coordinate measuring machine) for taper angle, bore concentricity, and thread pitch accuracy. Runout is verified with a dial indicator at the nose and at 50 mm from the nose — both must read under 0.005 mm. Surface finish is measured with a profilometer to confirm Ra 0.4 µm or better on the taper and bore. Collets are tested with a calibrated test bar for grip force and release. We attach a signed inspection report to each kit, so your incoming QC can verify our numbers in minutes.
| Specification | Value |
|---|---|
| Material (body) | 42CrMo alloy steel (AISI 4140) |
| Material (collet) | 65Mn spring steel |
| Hardness (body) | HRC 58-62 |
| Hardness (nut) | HRC 60-64 (nitrided) |
| Runout (TIR at nose) | 0.005 mm |
| Surface finish (taper/bore) | Ra 0.4 µm |
| Collet sizes | 1 mm – 20 mm (0.5 mm steps) |
| Taper options | BT30, BT40, BT50, CAT40, CAT50, HSK63A |
| Lead time | 15 days (standard kits) |
| MOQ | No MOQ — order 1 kit or 100 |
When you buy a chuck and collets from different suppliers, you risk mismatched tapers, uneven grip, and hidden runout. Our kit is manufactured and inspected as a single system. The collets are ground to match the chuck's taper angle within 0.002 mm, so you get consistent clamping force across all 10 collets. This is especially important for reaming and tapping, where a loose collet can cause oversize holes or broken taps. You also save on shipping and sourcing time — one PO, one shipment, one invoice.
There is no MOQ — you can order a single ER32 kit for testing or a full production batch, and we treat every order with the same priority.
Yes, we can replace any collet in the kit with custom sizes (e.g., 5.5 mm or 12.5 mm) at no extra cost, as long as the shank diameter falls within the ER32 clamping range of 1-20 mm.
Every kit goes through CMM inspection, runout testing with a dial indicator, and surface finish measurement, and we include a signed inspection report with each shipment.
Standard kits ship in 15 days from our Dongguan factory; custom taper or collet configurations take 20-25 days, and we can expedite to 7 days for urgent orders.
Send us your drawing or just list the taper type, collet size range, and quantity. We will reply within 12 hours with a firm price, lead time, and shipping cost. Email your inquiry to sc@bquq.com or message us on WhatsApp at +86 13713157787. We are a precision manufacturing factory in China with 20 years of CNC machining experience — no trading company markups, no vague promises. For more background on choosing the right toolholding system, check our CNC cutting tool selection guide and our CNC machining tolerances guide to match your application requirements.
| 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 |
