Complete range of structural fasteners for steel building assembly: high-strength friction grip bolts (HSFG), hex bolts, anchor bolts, self-drilling screws, nuts, and washers. Manufactured to international standards (ASTM, GB, DIN, ISO) with full material certification and batch test reports.
| Product Type | Grades / Standards | Sizes | Applications |
|---|---|---|---|
| HSFG Bolts (Friction Grip) | Grade 8.8, 10.9, 12.9; ASTM A325, A490; GB 1228; DIN 6914 | M12-M36 (1/2"-1-1/2") | Primary frame connections, moment joints, beam-column connections |
| Tension Control (TC) Bolts | Grade 10.9; ASTM A325TC, A490TC; GB 3632 | M16-M30 | Fast installation, calibrated tension, no torque wrench needed |
| Hex Bolts (Bearing Type) | Grade 4.6, 5.6, 8.8; ASTM A307, A325; DIN 931/933; GB 5782 | M6-M36 | Secondary connections, purlins, girts, bracing, general assembly |
| Anchor Bolts (Hold-down) | Grade 4.8, 5.8, 8.8; ASTM F1554 Gr.36/55/105; DIN 529 | M12-M48, length 100-1000mm | Column base plates, equipment anchoring, foundation connections |
| Self-Drilling Screws | Class 10.22, 12.9; ASTM C1513; DIN 7504 | M4.2-M6.3, length 13-125mm | Sandwich panel fixing, purlin-to-sheeting, cladding installation |
| Nuts & Washers | Grade 8, 10, 12; ASTM A563; DIN 934/125/127; GB 6170/97.1 | M6-M48 | Matching all bolt types, flat/spring/structural washers |
| Property | Grade 8.8 | Grade 10.9 | Grade 12.9 |
|---|---|---|---|
| Tensile Strength (min) | 800 MPa | 1000 MPa | 1200 MPa |
| Yield Strength (min) | 640 MPa | 900 MPa | 1080 MPa |
| Material | Medium carbon steel (40Cr, 35CrMo) | Alloy steel (42CrMo, 35CrMo) | Alloy steel (42CrMo4, SCM440) |
| Surface Treatment | Black oxide, zinc plated, hot-dip galvanized, Dacromet | Black oxide, zinc plated, Dacromet, PTFE coated | Black oxide, zinc plated, Dacromet |
| Preload (M20 example) | 110 kN | 155 kN | 185 kN |
| Typical Use | Standard connections, moderate loads | Heavy connections, moment frames, cranes | Ultra-heavy, seismic, special structures |
90° bent end for concrete embedment. Most common for steel column bases. Sizes M12-M36, embedment 200-600mm.
Hooked end for higher pull-out resistance. Used for heavy columns and dynamic load equipment. Sizes M16-M48.
Anchor bolt with welded bearing plate at embedded end. Maximum pull-out capacity for heavy structures and crane runways.
Chemical anchors and mechanical expansion bolts for retrofitting existing concrete. ETA/ICC certified for seismic and cracked concrete.
A: Friction grip bolts (HSFG) are preloaded to create clamping force that transfers load through friction between connected plates — no slip occurs under service loads, making them ideal for moment connections and fatigue-critical joints. Bearing type bolts transfer load through direct bearing of the bolt shank against the hole wall — they are cheaper and simpler to install but allow some slip and are used for secondary connections. HSFG bolts require Grade 8.8+ and controlled preloading; bearing bolts can be Grade 4.6-8.8 and are tightened to snug-tight only.
A: Bolt sizing is based on: (1) applied load (shear, tension, combined), (2) connection type (friction vs bearing), (3) bolt grade, (4) plate thickness and material, (5) edge distance and spacing per code. Our structural engineers provide bolt schedules with every project — including bolt mark, size, grade, quantity per connection, and installation torque. For custom projects, we provide connection design calculations per AISC 360, Eurocode 3, or GB 50017.
A: Typical installation torque for Grade 10.9 HSFG bolts (preload = 70% of proof load): M16 = 185 N·m, M20 = 365 N·m, M22 = 490 N·m, M24 = 630 N·m, M27 = 900 N·m, M30 = 1200 N·m. These are approximate values — actual torque depends on: nut factor (K-value, typically 0.12-0.18 for lubricated bolts), bolt condition, coating type, and calibration of torque wrench. We provide project-specific torque charts and recommend calibrating torque wrenches before installation. For critical connections, tension control (TC) bolts eliminate torque uncertainty by twisting off at calibrated tension.
A: Yes, we offer custom marking and packaging for projects: (1) Bolt head marking with project logo, grade, and manufacturer code; (2) Color-coded packaging by bolt size/grade for easy site identification; (3) Per-connection kit bags labeled with connection mark (e.g., "B1-C1", "Rafter-Joint-3") for fast erection; (4) Custom packing lists organized by erection sequence or building zone. This reduces on-site sorting time by 40-60% and minimizes installation errors. Minimum order for custom packaging applies.
A: For a typical single-story portal frame warehouse (10-20m span, 6-8m eave height), column base plates typically use: 4 pieces of M20-M24 Grade 5.8/8.8 anchor bolts, embedment length 300-450mm, with 100x100x10mm base plate. For heavier frames (crane buildings, >20m span, high wind/seismic zones), use M24-M30 Grade 8.8 anchor bolts with 500-700mm embedment and thicker base plates. Anchor bolt sizing depends on: column uplift force (wind), shear force, base plate size, concrete strength, and anchor edge distance. We provide anchor bolt schedules with every project, including exact size, embedment, and template drawings for foundation contractor.
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