Q355B Steel Bailey Bridge

A Q355B steel bailey bridge starts with the right material. Q355B is a low-alloy high-strength structural steel. Yield strength is no less than 355 MPa. Tensile strength runs 470–630 MPa. That is roughly 30% more load capacity than Q235B, and about 30 MPa higher yield than Q345B. With Q355B, you either use less steel for the same span, or carry heavier traffic with the same sections. We run Q355B steel bailey bridges with incoming material verification per batch. No grade mixing. No substitutions.

Q355B's higher yield point shows up in two places on a bailey bridge: longer spans and heavier load classes. The truss panel takes bending. Chords handle tension and compression. Pin holes and web members resist shear. Q355B lets the chord carry more tension at the same cross-section. Stress distribution at pin and lug joints is less strained. Put simply, a Q355B panel does what a Q235B panel cannot. The section does not change. Only the material grade does. That is how the performance ceiling moves up.

A Q355B steel bailey bridge uses the same structural format as a standard bailey bridge. Panels are 3m × 1.5m. Pin holes and chord bolt holes are fully interchangeable. The only change is the steel grade. A standard panel weighs about 306 kg. The high-shear type runs 354 kg. Panel pins are 30CrMnTi, matched to Q355B chords. Transoms, sway braces, and chord reinforcements keep the same connection dimensions. Q355B components swap directly with Q345B or Q235B parts. Only the load-bearing members change grade.

Material standard: GB/T 1591-2018

Yield strength: ≥355 MPa (thickness ≤16mm)

Tensile strength: 470–630 MPa

Elongation: ≥22%

Impact test temperature: 0°C

International equivalents: ASTM A572 Gr.50 / EN S355JR-

Panel size: 3000mm × 1500mm × 176mm

Panel weight: 306 kg (standard) / 354 kg (high-shear)

Span range: 9m to 60m+

Load class: Auto-10 to Trailer-80

Surface treatment: Hot-dip galvanized / painted

A Q355B steel bailey bridge suits projects where load matters and weight is watched. Mining haul roads - repeated heavy traffic favors Q355B's fatigue performance over Q235B. Municipal river crossings - people and equipment work below, so redundancy matters. Cold-region temporary bridges - Q355B passes the 0°C impact test, so it resists brittle fracture in low temperatures. For export projects specifying ASTM A572 Gr.50, Q355B maps directly. No grade conversion needed.

Jiangsu Jiuzhou Bridge Engineering Co., Ltd. Bailey panels, pins, transom clamps, and chord reinforcements. Q355B available by rolling order. Send your drawings for a quote.