Carbon Steel Hex Bar — Factory Direct Supplier | Huaxia-Steel
Huaxia-Steel manufactures and exports carbon steel hexagonal bars in grades A36, S235JR, S45C, S50C, and 1045 for machinery construction, fastener blanks, valve components, and precision engineering applications. Hex bars are available hot-rolled, cold-drawn, or rough-turned, with across-flat dimensions from 10mm to 100mm and length cut to customer specification.
Product Overview
Hexagonal bars provide superior wrench grip and anti-rotation properties compared to round bars, making them essential for bolt heads, nuts, hydraulic fittings, and tooling fixtures. Carbon steel hex bars offer cost-effective machinability and respond well to induction hardening for wear-resistant surfaces.
Specifications
| Parameter | Standard Range | Tolerance |
|---|---|---|
| Across-Flats (AF) | 10 – 100 mm | h11 (cold drawn) / +0.5mm (hot rolled) |
| Length | 3,000 – 6,000 mm | +50 mm / 0 mm |
| Corner Radius | ≤ 1.5 mm (cold drawn) | — |
| Straightness | ≤ 1 mm/m (cold drawn) | ≤ 3 mm/m (hot rolled) |
| Surface Finish | Bright (cold drawn) / Black (hot rolled) | — |
| Twist | ≤ 1° per meter | — |
Available Grades and Properties
| Grade | Standard | Typical Hardness (HB) | Application |
|---|---|---|---|
| A36 | ASTM A36 | 140 – 190 | Structural bolts, general machinery |
| S235JR | EN 10025-2 | 120 – 160 | Low-stress fasteners, brackets |
| S45C / 1045 | JIS G4051 / ASTM A29 | 170 – 210 | Medium-strength bolts, shafts, gears |
| S50C / 1050 | JIS G4051 / ASTM A29 | 180 – 230 | High-strength fasteners, die holders |
Manufacturing Standards
- ASTM A29 / A29M: General requirements for carbon steel bars
- ASTM A108: Steel bar, carbon and alloy, cold-finished
- JIS G4051: Carbon steels for machine structural use
- EN 10060: Hot rolled round steel bars — general tolerances
- GB/T 702: Hot-rolled steel bars — dimensions, shape, weight and tolerances
Applications
- Fastener blanks: Hex bolt heads, nuts, and studs via cold forging or machining
- Hydraulic fittings: Adapter bodies, couplings requiring wrench flats
- Machine construction: Adjusting screws, locating pins, tool holders
- Valve components: Stem extensions, bonnet fasteners
- Automotive: Suspension bolts, steering linkages
Quality Assurance
- Dimensional verification: Across-flats measured with calipers at three positions; corner radius checked with radius gauges
- Straightness test: Rolled on inspection table under 1m straightedge
- Surface inspection: Visual 100%; cracks, laps, and seams not permitted
- Chemical analysis: Spectrometric per heat; carbon deviation ≤ ±0.02%
- Ultrasonic test: Available for sizes ≥ 25mm AF on request
- Third-party certification: Mill test certificates per EN 10204 3.1 or 3.2
Packaging and Shipping
- Bundling: Hexagonal bundles (hex-to-hex stacking), steel strapping at 4 points minimum
- Surface protection: Rust-preventive oil (VDW or solvent-based); optional VCI film wrap
- Marking: Paint-marked with grade, heat number, and bundle number on each end
- Container loading: 20’GP: 20 – 25 MT; 40’HC: 25 – 27 MT
- Special packing: Wooden crates for polished cold-drawn bars ≤ 25mm AF
Request pricing and availability for carbon steel hex bars — provide across-flats dimension, grade, quantity, and required surface condition (hot rolled / cold drawn). Custom cutting and chamfering available.
