Carbon Steel Hex Bar — Factory Direct Supplier | Huaxia-Steel
Carbon steel hex bar is a versatile profile used extensively in the production of fasteners, fittings, valve components, and machined parts. The hexagonal cross-section provides natural wrench flats for assembly and eliminates the need for secondary machining operations to create grip surfaces. Huaxia-Steel supplies hot-rolled and cold-drawn carbon steel hex bar in a comprehensive range of sizes and grades, with tight dimensional tolerances and full material certification.
Product Specifications
| Parameter | Hot-Rolled | Cold-Drawn |
|---|---|---|
| Size Range (AF) | 13-100 mm | 8-65 mm |
| Length | 4-6 meters (standard); cut-to-length available | 3-4 meters (standard); 6m on request |
| AF Tolerance | ±0.4 mm to ±0.8 mm | h11 (±0.09 mm to ±0.19 mm) |
| Straightness | ≤4 mm/m | ≤1 mm/m |
| Surface Finish | As-rolled with mill scale | Bright drawn (Ra ≤3.2 µm) |
| Corner Radius | ≤0.3 × AF | Sharp (≤0.15 mm) |
| Packing | Bundled with steel straps | Bundled, VCI paper + PE film for export |
Available Grades
| Grade | Standard | Carbon % | Typical Hardness | Best For |
|---|---|---|---|---|
| SAE 1018 | ASTM A108 | 0.15-0.20 | 126-143 HB | General machining, low-stress fasteners |
| SAE 1045 | ASTM A108 | 0.43-0.50 | 170-210 HB | Medium-strength shafts, heat-treatable |
| S45C | JIS G4051 | 0.42-0.48 | 167-229 HB | Precision machined components |
| 12L14 | ASTM A108 | ≤0.15 | 121-163 HB | High-speed automatic machining |
| AISI 1144 | ASTM A108/311 | 0.40-0.48 | 190-240 HB | Stress-proof quality, high-strength |
Manufacturing Standards
- ASTM A108: Standard specification for cold-finished carbon steel bars (all grades)
- ASTM A29/A29M: General requirements for hot-rolled and cold-finished bars
- JIS G4051: Carbon steels for machine structural use (S-C grades)
- EN 10277: Bright steel products — technical delivery conditions
- DIN 176: Hexagon bar tolerances (withdrawn but still referenced)
Hex Bar Size Chart (Common AF Sizes)
| AF (mm) | Weight (kg/m) | Common Wrench Size | Typical Application |
|---|---|---|---|
| 8 | 0.44 | 8 mm | Small set screws, grub screws |
| 10 | 0.68 | 10 mm | Small bolts and fittings |
| 13 | 1.15 | 13 mm | Standard hex bolts |
| 17 | 1.96 | 17 mm | M10 hex bolts, fittings |
| 19 | 2.45 | 19 mm | M12 hex bolts |
| 22 | 3.29 | 22 mm | M14 hex bolts, hydraulic fittings |
| 24 | 3.92 | 24 mm | M16 hex bolts |
| 27 | 4.96 | 27 mm | M18 hex bolts, valve stems |
| 32 | 6.97 | 32 mm | M22 hex bolts, large fittings |
| 36 | 8.83 | 36 mm | M24 hex bolts, pump shafts |
| 41 | 11.45 | 41 mm | M27 hex bolts, hydraulic cylinder rods |
| 46 | 14.41 | 46 mm | M30 hex bolts, large valve stems |
| 50-100 | 17.05-68.21 | Custom | Heavy machinery, custom fittings |
Weight calculated using formula: W = 0.866 × AF² × 7.85 / 1000 (kg/m)
Typical Applications
- Fastener production: Hex bar is the preferred feedstock for CNC-turned hex bolts, studs, set screws, and threaded rods — the hexagonal profile eliminates first-operation milling
- Valve components: Stem blanks, bonnet nuts, and packing gland components machined directly from hex bar, reducing machining time by 30-50% vs. round bar
- Hydraulic fittings: Adapters, plugs, and connector bodies for hydraulic and pneumatic systems at pressures up to 420 bar (6,000 psi)
- Pump shafts: Medium-carbon heat-treated hex bar for pump drive shafts where the hex profile serves as the coupling interface
- General machining: Standoffs, spacers, bushings, and custom components where the hex profile provides anti-rotation or assembly features
Quality Assurance
- Mill Test Certificate (EN 10204 3.1): Chemical composition, tensile strength, yield strength, elongation, and hardness
- Dimensional inspection: AF (across flats) measurement at both ends and middle of each bar; straightness check with feeler gauge and surface plate
- Surface quality: 100% visual inspection for seams, laps, and surface defects; optional eddy current testing
- Heat number traceability: Bar ends color-coded or stamped with heat number corresponding to MTC
- Third-party inspection available: SGS, Bureau Veritas, or TUV at mill or during loading
Packaging and Shipping
Standard export packaging:
- Cold-drawn hex bars bundled in 500-1,000 kg lifts with 3-4 steel strapping bands
- Each bundle wrapped in VCI paper + polyethylene film for corrosion protection during ocean freight
- Hot-rolled hex bars bundled without individual wrapping; desiccant bags placed in container
- Wooden dunnage between bundles to prevent surface damage
- Loading into 20ft or 40ft containers; typical load 22-26 tons per 20ft container
- Custom cut-to-length packaging available (crated for precision-machined dimensions)
Request a Quotation for Carbon Steel Hex Bar
Contact Huaxia-Steel with your hex bar requirements — grade, AF size, length, tolerance (hot-rolled or cold-drawn), quantity, and destination port. We respond with competitive FOB/CIF pricing within 24 hours, including lead time and shipping details.
