Our ASTM A307 Carbon Steel Bolts are the workhorse fasteners construction and infrastructure crews rely on. Made from Grade A carbon steel (per ASTM A307), they deliver 60,000 PSI tensile strength - that's 15% stronger than basic hardware store bolts. We cold-forge the hex heads for tighter grain structure, proven in third-party tests to handle 30% more torque before rounding. These are your go-to bolts for structural connections in non-corrosive environments: bridge scaffolding, transmission towers, or heavy equipment assembly. Compared to stainless alternatives, you'll save 50-65% per thousand pieces while getting ASME B18.2.1-compliant reliability.
Every ASTM A307 Carbon Steel Bolts get precision finishing:
1.Cold-forged from continuous-cast billets (reduces porosity vs. scrap metal)
2.Thread-rolled to ASME B1.1 Class 2A fit (lasts 2x longer than cut threads in vibration tests)
3.Zinc-plated per ASTM B633 Type II (48-hour salt spray certified)
4.100% magnetic particle inspected (catches sub-surface flaws cheaper suppliers miss).We chamfer thread ends - stops binding during installation and reduces worker injuries.
Running 16 automated lines with:
1.25 million-piece monthly capacity (handles infrastructure booms)
2.Real-time PMI checks (XRF guns verify carbon content on the spot)
3.Laser-etched grade markings (won't fade like paint stamps)
Barcode-tracked batches from wire coil to crate
Need volume yesterday? Our UK warehouse stocks 15M+ Grade A carbon steel bolts (1/4"-4" sizes) - all CE marked and ready for 48hr EU delivery.
For wholesale partners
1.Volume power: Orders >100,000pcs get 10% discount + free RoHS certs
2.On-time promise: 98% ship in 7 working days (delayed? We cover 50% air freight)
3.Strength guarantee: Shear below 45,000 PSI? Full replacement + $300 compensation
4.Compliance ready: Free CE/UKCA/REACH docs - clears customs in <24hr
ASTM A307 (Specification for Carbon Steel Externally Threaded Fasteners)
Carbon steel (low to medium carbon content; typically C ≤ 0.30%)
Type A: General-purpose fasteners for light to moderate loads.
Type B: Higher tensile strength variant for applications requiring greater load-bearing capacity.
Type C: Historically used for structural anchoring (now superseded by F1554 Grade 36).
Mechanical Properties
Tensile Strength: Type A: Min. 60 ksi (414 MPa); Type B: 60–100 ksi (414–690 MPa).
Yield Strength: Not specified (depends on material ductility).
Elongation: Min. 18% (for bolts ≤ 1 inch diameter).
Thread Standards
Unified National Coarse (UNC) threads as per ASME B1.1; available in other thread types on request.
Diameter: 1/4 inch to 4 inches (6.35 mm to 101.6 mm).
Length: Typically 10 mm to 800 mm (custom lengths available based on application).
Plain (uncoated), zinc-plated (for corrosion resistance in mild environments), or other coatings (e.g., hot-dip galvanized) as required.
Applications
Construction: Wood/light steel structural connections, concrete formwork, and general building fixtures.
Machinery: Assembly of light equipment, pumps, and non-critical mechanical components.
Piping: Joining non-high-pressure flanges and low-stress pipe systems.
Key Features
Cost-effective: Economical due to low carbon steel composition.
Easy to machine: Good ductility and machinability for threading and forming.
Versatility: Suitable for non-high-stress, general-purpose fastening.
Frequently Asked Questions
Q: Do you offer discounts for bulk orders?
A: Yes, we have tiered pricing for bulk orders. The larger the quantity, the more competitive the price.
Q: Can you share some of your customer references or case studies?
A: Sure, we can share case studies of customers in your industry (e.g., oil & gas, construction) while protecting their privacy.
Q: What is your policy for product returns or replacements?
A: If products have quality issues caused by us, we'll arrange replacements or refunds within 30 days of receipt.
