Steel Structure High Strength Bolts for Bridge Construction
-- Steady & Reliable Manufacturer --
Introduction
Steel structure high strength bolts are heavy hex bolt, nut and washer sets used in friction-grip and bearing connections of bridges, towers and buildings. Chinese standards GB/T 1228 to 1231 cover the 8.8S and 10.9S grades, and twist-off sets follow GB/T 3632. Each bolt set is tested for torque coefficient so that the preload is consistent when the joint is tightened.
Shanghai Soverchannel Industrial Co., Ltd. produces high strength bolt sets in M16 to M30 at its Nantong Jinzhai Hardware plant, with alloy steel heat treatment, torque coefficient reports and matching nuts and washers packed as sets.
Specification
Specification
| Standard | GB/T 1228, GB/T 1231; ASTM A325 and A490 on request |
| Grade | 8.8S or 10.9S |
| Material | Alloy steel such as 20MnTiB or 35VB |
| Size range | M16 to M30 (most common) |
| Length | 40 mm to 300 mm |
| Set | Bolt, nut and washer(s) |
| Surface finish | Plain oiled, hot-dip galvanized, Dacromet |
| Test | Torque coefficient and preload |
| Packing | Wooden cases or pallets |
| Note | Confirm design code and bolt set specification before ordering |
Advantages
- Full-length thread: gives flexibility on grip length and allows fastening into tapped holes without cutting the bolt down.
- Interchangeable dimensions: head size and pitch follow DIN and ISO tables, so bolts match existing nuts and tools.
- Coating choice: a finish can be matched to indoor, outdoor or marine exposure without changing the bolt design.
- Traceable batches: heat numbers and test data can be tied to each production lot.
- Mixed-size loading: several sizes can be combined in one shipment to reduce stock risk.
Applications
Machinery Assembly
Frames, gearbox housings, motor mounts and guards where a full thread gives maximum engagement.
Equipment Maintenance
Replacement bolts for pumps, conveyors and crushers, ordered by standard number and class.
Steel Framing
Brackets, base plates and light structural connections.
Automotive Chassis
Cross-members, subframe brackets and suspension mounts where class 8.8 is specified.
Agricultural Machinery
Implement frames and hitch assemblies exposed to dirt and vibration.
Core Features
- Hex head: standard wrench sizes allow fast tightening with common tools.
- Quenched and tempered core: delivers the 800 MPa tensile level required for class 8.8.
- Rolled thread: improves fatigue performance compared with cut threads.
- Gauge-checked threads: go and no-go gauges confirm fit before packing.
Frequently Asked Questions
EN 10204 3.1 MTC
Every batch comes with full traceability, including material certificates, tensile strength, and hardness test reports to ensure smooth project acceptance.
500+ Tons/Month Capacity
Direct supply from our Nantong Jinzhai Hardware plant. Standard sizes (M8-M24) are kept in stock for 3-7 days rapid dispatch.
100% Thread Gauge Check
Strict go/no-go gauge inspection after thread rolling guarantees perfect 6g tolerance fit, eliminating the risk of stripped threads.
OEM/ODM Flexibility
Support custom lengths, special head shapes, fine threads, and head marking (Logo/Grade) with fast CAD drawing confirmation.
Export-Standard Packaging & Logistics
We understand the harsh conditions of international shipping. Our packaging is designed to prevent rust, damage, and customs delays.
- ISPM 15 Fumigation-Free Wooden Pallets: Meets global customs quarantine requirements for hassle-free clearance.
- Heavy-Duty Cartons + Inner PE Liner: Double protection against high humidity and salt spray during ocean freight.
- Customized Shipping Marks: Clear, durable labels with your company info, item number, and quantity for easy warehouse counting.
- Transparent Packing Data: We provide exact CBM, GW, and carton dimensions in the quotation to help you calculate shipping costs accurately.
Related Tags
- Black Oxide Alloy Steel Hex Head Bolts
- Carbon Steel Self Tapping Screws for Sheet Metal
- DIN 933 Grade 8.8 Hex Head Bolts
- ASTM A193 B7 Threaded Rods for Flange Bolting
- Hot Dip Galvanized Grade 8.8 Hex Bolts
- Phosphate Coated Cylinder Head Flange Bolts
- Automotive Hex Flange Bolts Grade 10.9
- ISO 4762 Alloy Steel Socket Head Cap Screws
- ISO 7379 Alloy Steel Shoulder Screws
- ASTM A325 Heavy Hex Structural Bolts

中文简体
Português
Español
Deutsch
русский
عربى



