If you’re shortlisting wire bolts suppliers, here’s the on-the-ground perspective from a journalist who’s spent way too many hours in bolt mills. Double end stud bolts—threads on both ends, solid shank in between—quietly hold together engines, pumps, and structural steel. The difference between a good stud and a great one often comes down to heat-treatment discipline and thread geometry. Sounds nerdy, but it’s what keeps flanges sealed and turbines calm.
Demand is steady in oil & gas, power gen, and construction. Actually, the post-2023 trend is toward traceability—lot-coded studs, MTRs, and coatings that survive coastal air. Many buyers also want fast-turn custom lengths. In Yongnian (Handan, Hebei, China)—the world’s fastener capital—capacity has scaled up, and that’s where this product is made: Southwest of Road Taibai, Yongnian District. It’s a hub where you can get prototypes in days, not weeks.
| Product | Double end stud bolts |
| Standards | ASME B18.31.2; ASTM A193/A194 (B7, B8, B8M); ISO 898-1 (8.8/10.9) |
| Material | 35CrMo/4140 (B7), 304/316 (B8/B8M), carbon steel Q235/45#, alloy steel |
| Diameter | M6–M48 (¼"–2") |
| Length | 40–1200 mm (custom cut to ±0.5 mm ≈ real-world) |
| Thread | Metric coarse/fine; UNC/UNF; 2A/6g; rolled or cut |
| Coatings | Black oxide, zinc, HDG, Geomet/Dacromet, PTFE for anti-galling |
| Mechanical data | 8.8 ≈ 800–830 MPa TS; 10.9 ≈ 1040–1100 MPa; B7 proof 720 MPa (typ.) |
Flange joints in pipelines, pump/motor mounting, wind tower segments, chemical vessels, and structural splice plates. Customers tell me B7 with PTFE washers reduces galling on hot flanges—small tweak, big win.
Service life? Around 10–25 years in normal industrial atmospheres; coastal/offshore varies wildly with coating and maintenance cycles.
| Vendor type | MOQ | Lead time | Price (index) | Certs/Testing | Customization |
|---|---|---|---|---|---|
| Factory, Yongnian (origin above) | ≈ 200–500 pcs | 7–15 days | Low | ISO 9001; MTRs; tensile/salt spray | High (odd lengths, coatings) |
| Trading company | Flexible | 10–25 days | Medium | Depends on partner mills | Medium |
| Overseas distributor | Box/stock | Ex-stock or 2–5 days | High | Local QA; quick replacements | Low–Medium |
Options include stepped shanks, double chamfer, partial threads, left/right combos, and PTFE nuts for anti-seize. One EPC client said their flange leak rate dropped after switching to rolled threads and matched hardness nuts—simple pairing, big reliability bump. Many customers say packing matters: foam separators prevent thread dings and save rework time.
Ask for heat charts (quench/temper), proof-load data, and a salt-spray report for your exact coating. Verify to ASME B18.31.2 and ASTM A193 grade callouts. If a vendor hesitates on MTRs—walk. For urgent turnarounds, wire bolts suppliers near raw-material sources (like Yongnian) usually win on speed.
A coastal wastewater plant shifted to 316 studs with Geomet and PTFE nuts; maintenance intervals stretched from 9 to ≈ 18 months, and galling incidents basically disappeared. Not magic—just matching material to environment.