Product Overview
Huaxia-Steel supplies carbon steel hexagonal bars (hex bar) — six-sided solid bar specified across flats (A/F) — in hot-rolled and cold-drawn conditions. Hex bar is the standard feedstock for hex fasteners: nuts, bolts, and set screws are turned or cold-headed from it, and the hex profile grips naturally in collets and chuck jaws, reducing machining time versus round stock.
We stock sizes from 10 mm to 100 mm across flats in grades 1018, 1045, S45C, 12L14, and 1144, with cold-drawn (CD) condition standard and tight tolerance for CNC feedstock users.
Size and Weight Table
Theoretical weight per meter for carbon steel hex bar (density 7.85 g/cm³):
| A/F (mm) | Weight (kg/m) | A/F (mm) | Weight (kg/m) |
|---|---|---|---|
| 10 | 0.68 | 36 | 8.81 |
| 13 | 1.15 | 41 | 11.44 |
| 17 | 1.97 | 46 | 14.39 |
| 19 | 2.45 | 55 | 20.63 |
| 22 | 3.29 | 65 | 28.80 |
| 24 | 3.91 | 75 | 38.27 |
| 27 | 4.95 | 90 | 55.11 |
| 30 | 6.12 | 100 | 68.03 |
Custom A/F sizes and imperial equivalents (1/2″ to 3″) produced to order; minimum rolling quantities apply for non-stock sizes.
Dimensional Tolerances
| Parameter | Hot Rolled | Cold Drawn |
|---|---|---|
| Across flats, 10–30 mm | ±0.5 to ±0.8 mm | −0.05 / +0.15 mm (h11 window) |
| Across flats, 30–60 mm | ±0.8 to ±1.2 mm | ±0.15 mm |
| Across flats, >60 mm | ±1.5 mm | ±0.25 mm |
| Straightness | ≤4 mm/m | ≤1.5 mm/m (precision ground: ≤0.5 mm/m) |
| Twist | — | ≤1° per meter |
| Length tolerance | +50/0 mm | +15/0 mm standard; exact ±3 mm on request |
Available Grades
| Grade | Condition | Hardness (Typical) | Best For |
|---|---|---|---|
| 1018 / Q235 | CD | HB 126 max | Low-strength fasteners, general machining |
| 1045 / S45C | CD or Q&T | HB 170–220 (CD); 28–32 HRC (Q&T) | Nuts, bolts, shafts, couplings |
| 12L14 | CD | HB 163 max | High-speed automatic screw machining |
| 1144 | CD | HB 217–248 | Stress-proof shafting, induction hardening |
| 4140 / 42CrMo4 | Q&T | 26–32 HRC core | High-strength fasteners, tooling |
Manufacturing Standards
- Material: GB/T 699 (quality carbon), ASTM A29/A108, EN 10277-2/3, JIS G4051
- Hex dimensions: GB/T 699 hex rolling schedule; DIN 1015 equivalence for European projects
- Production routes: hot-rolled (+AR), cold-drawn (+C), quenched-and-tempered (+QT) for 1045/4140
- Certification: EN 10204 3.1 with per-heat chemistry and mechanical results
Applications
- Hex nuts, hex bolts, set screws, and threaded rod stock (cold-heading or machining routes)
- Valve stems, pump shafts, and fittings on CNC lathes
- Hand tool components, clamps, and machine hardware
- Fastener bar stock for automatic screw machines (12L14) and cold headers (1018/1045)
- Induction-hardened wear components (1144)
Quality Assurance
- Across-flats and twist measurement on sampled bars; go/no-go hex gauges for CD sizes
- Chemistry verified per heat; free-machining grades checked for lead/sulfur distribution
- Hardness testing on 2–3 bars per lot, results on the 3.1 certificate
- Decarburization limit (≤1.5% of A/F) for Q&T grades destined for threading
- Surface: no seams, laps, or die marks beyond drawing-grade limits; ultrasonic testing (SEP 1927) available on request
Packaging and Shipping
- Bundles 1–2 tonnes, plastic-wrapped for CD finish bars (surface protection); heat tags per bundle
- 20ft container ~25 tonnes; 12 ft (3.6 m) and 20 ft (6 m) standard lengths; custom cut lengths available
- Moisture-barrier paper + VCI options for sea freight to humid destinations
- FOB, CFR, CIF, DAP; ports: Tianjin, Qingdao, Shanghai
Why Buy Hex Bar from Huaxia-Steel
- Cold-drawn quality suited to automatic lathe feeding — consistent A/F, low twist, straight bars
- Free-machining and standard grades from one supplier for mixed fastener programs
- Small MOQ: 500 kg per size for stock sizes, mixed-size containers accepted
- 15+ years export experience with fastener industry buyers across SEA, Middle East, and South America
Request a Quote
Send us your A/F sizes, grades, and lengths — we quote within 24 hours with current pricing. Sample bars for machining trials available on request. Email [email protected] or use the inquiry form below.
