These are CNC machined threaded fasteners—bolts, screws, and studs cut from solid bar stock on 5-axis mills and Swiss lathes, not rolled or cold-headed. You get ±0.005 mm thread pitch accuracy, 0.01 m
These are CNC machined threaded fasteners—bolts, screws, and studs cut from solid bar stock on 5-axis mills and Swiss lathes, not rolled or cold-headed. You get ±0.005 mm thread pitch accuracy, 0.01 mm total runout on the shank, and a 10-day lead time from drawing approval to shipment, with hardness up to 48 HRC for high-clamp-load joints. This is precision manufacturing for engineers who need a fastener that is also a precision component—not a commodity part from a bin.
Rolled threads compress the grain structure; machined threads cut it clean. For your application, this means no work-hardening cracks at the thread root and no micro-tears that propagate under cyclic load. We single-point thread on CNC lathes for pitches down to M1.6, or thread-mill on our DMG MORI 5-axis centers for blind holes and interrupted cuts. Runout is held to 0.01 mm on the pitch diameter—that is 50% tighter than DIN 13 class 6g allows. If your assembly uses a torque-to-yield strategy, machined threads give you a more predictable friction coefficient because the surface finish is consistent at Ra 0.8 µm, not the random peaks of a rolled thread.
We stock 12.9-grade alloy steel (AISI 4140), 17-4 PH stainless, and Inconel 718 for high-temp or corrosive environments. For aluminum fasteners, we use 7075-T6, not 6061, because it gives you 572 MPa yield strength and holds threads better under repeated assembly. Heat treatment is done in-house in a vacuum furnace: 4140 is quenched and tempered to 36-40 HRC for general duty, or 44-48 HRC for shear-critical joints. 17-4 PH is aged to H900 condition (40-44 HRC). Every batch gets a hardness test on three samples per furnace load—we log the curve, not just the peak.
We do not rely on a single ring gauge. Each CNC machined threaded fastener is checked three ways: a thread micrometer for pitch diameter, a functional go/no-go gauge per ISO 1502, and a profile projector for flank angle at 20× magnification. For critical aerospace or medical fasteners, we add a coordinate measuring machine (CMM) scan of the full thread profile—30 points per flank—and send you the report as a PDF. If you are designing for a press-fit or interference thread, we can hold pitch diameter to ±0.005 mm, which is tighter than any standard class. That is why engineers who need a bolt to also act as a locating dowel come to us.
Bare machined steel at Ra 0.8 µm is standard. For corrosion resistance, we offer zinc-nickel plating (1200-hour salt spray per ASTM B117) or trivalent passivation. But if your fastener sees cyclic bending, we recommend shot peening at 8-10 A intensity, which compresses the surface layer and raises fatigue limit by 30-40% compared to unpeened parts. For stainless fasteners, we offer electropolishing to Ra 0.2 µm—this removes the free-iron contamination that causes rust streaks on 304 parts. Each option is applied after heat treatment, so the coating does not affect hardness.
Our standard lead time is 10 business days for quantities up to 5,000 pieces. If you need a prototype or a bridge-tooling run, we can ship 50 pieces in 72 hours—but only if the material is in stock (we keep 4140, 7075, and 17-4 PH bar in 12 common diameters). For production runs above 5,000 pieces, we add 3 days for dedicated tooling and first-article inspection. Here is the honest part: if you want 10,000 M6×20 bolts in 5 days, we will tell you no on day one, not day nine. We give you a firm date in the quote, and we hit it 98.7% of the time (tracked over the last 200 orders).
Standard hex heads are easy. But your design might call for a tamper-proof 12-point star, a socket-head cap screw with a deeper-than-standard drive, or a flange head with a specific bearing surface angle. We machine all of these from solid, so there is no die cost and no minimum shape restriction. We have cut heads with 0.5 mm hex socket widths for miniature optics mounts, and we have made 300 mm long shoulder bolts with a 0.005 mm concentricity between the shoulder and thread. If you can draw it in SolidWorks or STEP, we can quote it—even if it is not in any fastener catalog.
| Specification | Value Range | Notes | | --- | --- | --- | | Material options | AISI 4140, 17-4 PH, Inconel 718, 7075-T6 | Custom alloys on request | | Thread size range | M1.6 to M64 | Unified (UN/UNF) also available | | Length range | 3 mm to 400 mm | Longer on special fixture | | Hardness | 36-48 HRC (steel), 40-44 HRC (17-4 PH) | Vacuum heat treated | | Thread pitch tolerance | ±0.005 mm | 50% tighter than class 6g | | Total runout | 0.01 mm | On shank and thread axis | | Surface finish | Ra 0.2 µm to Ra 1.6 µm | Electropolish or shot peen options | | Lead time | 72 hours (prototype), 10 days (standard) | Firm date in quote | | MOQ | 1 piece (no MOQ) | Prototype to 50,000 pcs | | Inspection report | CMM thread profile, hardness log | PDF included with shipment |No MOQ—we accept a single prototype piece for validation, and you keep the same tolerances as a 10,000-piece run because the process is identical.
Yes, any head geometry that is machinable from solid bar is possible; just send a STEP file or PDF drawing, and we will confirm tool access within 24 hours.
We use a 3-level plan: first-article full CMM inspection, in-process SPC on pitch diameter every 50 pieces, and a final functional go/no-go gauge check on 100% of the batch.
72 hours for up to 50 pieces in stocked materials (4140, 7075, 17-4 PH), including heat treatment and a hardness report; this is a firm commitment, not a target.
For the full picture on tool selection and tolerance design, read our CNC cutting tool selection guide and our CNC machining tolerances guide. These are the same internal standards we apply to every threaded fastener we cut.
Send your drawing (STEP, IGES, or PDF) and your target quantity. We will return a firm quote with a confirmed lead time within 12 hours—not a generic range. Email sc@bquq.com or WhatsApp +86 13713157787. If you are sourcing from a made in China precision manufacturing partner, you want one that answers fast and ships on time. That is BQUQ. No MOQ, no minimum, just machined fasteners that fit your tolerance stack.
| 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 |
