M24*200 Alloy Steel High-Strength Bolts for Steel Structure

The M24*200 specification (24mm diameter, 200mm length) accommodates thick connection packages involving multiple splice plates, gusset plates, and structural flange connections.
Grade 8.8 alloy steel provides a minimum tensile strength of 800 MPa with excellent toughness; Grade 10.9 (minimum 1040 MPa) is available for critical primary structural nodes and wind/seismic load-resisting frames. 
Phosphate surface treatment ensures consistent torque-preload relationships during controlled tightening with calibrated torque wrenches or hydraulic tensioners — essential for achieving specified preload in structural friction joints.
All products are manufactured and tested to GB/T 1228, GB/T 3632, DIN EN 14399, and ASTM A325/A490 standards, with full mill certificates and mechanical test reports available on request. Compatible with Grade 10H heavy hexagonal nuts and hardened washers per Chinese structural standards.
Available surface finishes include Black oxide, HDG, PTFE, and Dacromet for varied exposure conditions. OEM/ODM customization supported for non-standard lengths and material grades.