What This Hydraulic Power Chuck Does Differently on Your CNC Lathe This is a CNC machined hydraulic power chuck with a 3-jaw configuration, designed specifically for high-speed CNC turning operations
Get a quote
-
English
- sc@bquq.com
What This Hydraulic Power Chuck Does Differently on Your CNC Lathe This is a CNC machined hydraulic power chuck with a 3-jaw configuration, designed specifically for high-speed CNC turning operations
This is a CNC machined hydraulic power chuck with a 3-jaw configuration, designed specifically for high-speed CNC turning operations where bar stock or blank parts must be gripped without deflection. The concrete benefit: we hold concentricity runout to 0.005 mm (0.0002") TIR at the jaw face, with a gripping force repeatability of ±2% across 10,000 cycles, and we ship standard sizes in 15 days. The body is through-hardened to HRC 58-62, so the chuck body will not distort or lose preload even when you run interrupted cuts at 3,500 RPM.
Manual collets require a spindle stop, a drawbar wrench, and a second operator action. This hydraulic power chuck uses a built-in piston that moves all three jaws radially inward with equal force — no drawbar, no manual torque, no scrap from uneven clamping. For a typical 45 mm steel shaft, the hydraulic system generates 32 kN of radial force, which is 2.3 times the force of a comparable pneumatic chuck. That force keeps the part from lifting off the jaw seats during heavy roughing passes of 4 mm depth of cut. The result: you can program a complete turning cycle without re-tightening, and the cycle time drops by 18% compared to manual collet changes.
We machine the chuck body from 42CrMo4 (AISI 4140) alloy steel, then case-harden it to HRC 58-62 at a depth of 0.8-1.2 mm. The jaws are made from 20CrMnTi (AISI 8620) carburized steel, with a hardened surface of HRC 60-63 and a core that stays ductile at HRC 35-40 — that combination prevents jaw tooth breakage when gripping thin-walled tubes. We grind the bore and the front face in one setup on a jig grinder, so the mounting pilot and the jaw slots are concentric to within 0.003 mm. The internal hydraulic piston is hard anodized aluminum (6061-T6), which gives a low friction surface and eliminates galling against the steel cylinder wall. Every surface that touches the workpiece is ground to Ra 0.4 µm, and the external body is bead-blasted to Ra 1.6 µm for corrosion resistance.
Standard power chucks use 60° serrated jaws that only bite at the very edge of the serration. We cut a three-start spiral serration with a 1.0 mm pitch and a 45° included angle on the jaw face, using a custom-formed carbide cutter on a 5-axis CNC. This geometry creates a self-locking wedge effect — the more radial force you apply, the deeper the serration bites, but the part does not rotate because the spiral angle is opposite to the spindle direction. We test every jaw set against a calibrated torque wrench: at 32 kN clamping force, a 50 mm shaft will not rotate under 450 N·m of torque. That is 3.2 times the torque required for a standard roughing pass on a 10 kW lathe spindle.
Each chuck leaves our Dongguan factory only after a 14-point inspection on a dedicated test rig. We measure TIR at the jaw face with a 0.001 mm resolution dial indicator, and we reject any unit above 0.005 mm. We also pull a full gripping force curve at 0, 5, 10, 15, and 20 bar hydraulic pressure, and compare it to the theoretical force equation for your specific jaw height. The hydraulic circuit is pressure-tested at 40 bar for 5 minutes — no external leaks, no internal bypass. We record all readings on a serialized test report that ships with the chuck. If you ask, we can also include a video of the actual runout test on your specific chuck before we crate it.
We machine the back plate to match either a flat mount with pilot (for manual turret lathes) or a through-hole mount for bar feed systems. Standard sizes we keep in stock: 6", 8", 10", and 12" chuck diameters, with through-bore diameters ranging from 26 mm to 91 mm. All chucks have a T-slot pattern on the front face that accepts standard hard jaws, soft jaws, or collet pads. If you have a specific spindle nose, we can machine the mounting pilot and bolt circle to match your exact machine — just send us the spindle drawing or the machine model. For a Mazak QT-200, we have a pre-machined back plate ready to bolt on in 24 hours.
| Specification | Value / Range |
|---|---|
| Chuck diameter | 6" (152 mm) / 8" (203 mm) / 10" (254 mm) / 12" (305 mm) |
| Through-bore diameter | 26 mm / 52 mm / 72 mm / 91 mm |
| Body material | 42CrMo4 (AISI 4140) alloy steel |
| Jaw material | 20CrMnTi (AISI 8620) carburized steel |
| Body hardness | HRC 58-62 (case hardened, depth 0.8-1.2 mm) |
| Jaw hardness | HRC 60-63 (surface), HRC 35-40 (core) |
| Concentricity runout (TIR) | ≤ 0.005 mm (0.0002") at jaw face |
| Surface finish (critical faces) | Ra 0.4 µm (ground), Ra 1.6 µm (body) |
| Max gripping force | 32 kN at 20 bar hydraulic pressure |
| Repeatability | ±2% over 10,000 cycles |
| Lead time | 15 days for standard sizes; 20 days for custom back plate |
| MOQ | No MOQ — order one piece for testing |
We run three 8-hour shifts on our Okuma and Mazak CNC lathes, and the chuck body goes through a single heat treatment batch of 20 pieces minimum — that way, the hardness curve is identical across all units. We use in-process gauging on the lathe: a Renishaw probe measures the jaw slot width after every 5th part, and the machine automatically compensates for tool wear. That is why we can promise a 0.005 mm runout without a final hand-lapping step. The 15-day lead time includes heat treatment, grinding, and assembly. If you need a prototype in 7 days, we can machine one from pre-hardened 4140 and skip the case hardening — but the hardness will be HRC 28-32, not HRC 58-62.
We have no MOQ — you can order one chuck for a prototype run, and the unit price is the same as a batch of 50.
Yes, we can machine the jaw slots and the jaw face to any profile you send, including special serrations for thin-wall tubes or hex bar stock, and we keep your original jaw drawings on file for repeat orders.
We perform a 14-point inspection including TIR, gripping force curve, and a 40-bar hydraulic leak test, and we send you the serialized test report with every shipment.
Standard sizes ship in 15 days, custom back plate orders take 20 days, and air freight from our factory to Los Angeles takes 3 days, so you can expect the chuck on your machine in under 3 weeks.
To quote your exact chuck, send us three pieces of information: your spindle nose type (A2-5, A2-6, etc.), the through-hole diameter you need, and your part diameter range. If you have a drawing of the back plate or the existing chuck, include that too — we can reverse-engineer the bolt pattern from a simple photo with a ruler in the frame. We will confirm the mounting dimensions in our quote within 12 hours. For a standard A2-6 mount with an 8" chuck, we can ship a fully assembled unit without asking for any drawing at all.
We are a 20-year-old precision manufacturing factory in Dongguan, China, with a dedicated 12-person CNC cell for chucks and fixtures. Our overhead is 40% lower than a comparable US or German shop, but our inspection equipment is the same grade — we use a Zeiss CMM and a Mitutoyo surface tester. That means you get a chuck with the same HRC, runout, and repeatability as a €6,000 German unit, but your landed cost is roughly €2,800 including air freight. We do not cut corners on material or heat treatment — we only cut the labor and overhead costs. Every chuck we ship is covered by a 12-month warranty against manufacturing defects, and we have replacement jaws in stock for 10 years after your purchase.
When you design your turning process, remember to pair this chuck with the right cutting tools — see our CNC cutting tool selection guide to match inserts to your material. And if you are pushing tolerances below 0.01 mm, read our CNC machining tolerances guide to understand what is achievable in production.
Send us your spindle drawing or the dimensions of your existing chuck, and we will reply with a firm quote within 12 hours — not a ballpark, a fixed price with a fixed lead time. Email us at sc@bquq.com, or message us on WhatsApp at +86 13713157787. We will confirm the mounting pilot, bolt circle, and through-bore size before we quote, so there are no surprises. No MOQ, no minimum order, no obligation — just a precise price for a precision chuck, made in China and inspected to international standards.
| 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 |
