Steel structure manufacturer since 2009 · 8 fabrication bases in China
Floor & Envelope
Purlins, girts, stairs and platforms that arrive with the frame
Secondary steel is small per piece and large in count. Supplied with the main frame, it uses the same model, hole patterns and packing list. Stairs and guard rails also have to pass a safety inspection, so we build them to the dimensions in the standard.
C100–C300
C purlin range
Z100–Z300
Z purlin range
1.5–3.0 mm
Thickness
Z275
Galvanizing, g/m²
Purlins and girts
C or Z section?
| Item | C purlin | Z purlin |
|---|---|---|
| Typical use | Simple spans, wall girts, edges | Continuous multi-span roofs |
| Lapping | Not nested | Nested laps at supports |
| Span efficiency | Lower | Higher on long runs |
| Sizes | 100–300 mm deep | 100–300 mm deep |
Cold-formed design per GB 50018, EN 1993-1-3 or AISI S100.
From our engineers
Why purlins fail, and what prevents it
Wind uplift. Under suction the unrestrained bottom flange is in compression. Sag rods or bridging hold it; without them a purlin twists and buckles.
Sag rods and ties. Spacing comes from the design; they also keep purlins straight during sheeting.
Fixings to the panel. The roof sheet restrains the top flange only if fixed at the designed spacing.
Galvanizing on cut ends. Pre-galvanized Z275 is cut and punched after coating; cut edges are protected by the zinc nearby in mild sites. Coastal sites need hot-dip after forming or higher coating mass.
Access steel
Guard rail and stair dimensions we build to
From EN ISO 14122-3 (industrial access). Your local code may differ; we build to the one you name.
| Item | Requirement |
|---|---|
| Guard rail needed when fall height exceeds | 500 mm |
| Guard rail minimum height | 1,100 mm |
| Knee rail clear spacing | Max 500 mm |
| Toe plate | Where the gap to an adjacent structure exceeds 20 mm |
| Stair handrail height | 900–1,000 mm above the step nose |
| Handrail diameter | 25–50 mm, 75 mm hand clearance |
For US projects, OSHA 1910.25 and 1910.29 apply; for buildings, the local building code.
Stairs, handrails and platforms
Access steel for plants and warehouses
Steel stairs
Straight, dog-leg and spiral stairs with chequer plate or grating treads.
Industrial platforms
Equipment and maintenance platforms with grating floors.
Handrails and ladders
Guard rails, cage ladders and toe plates.
Are purlins galvanized?
Pre-galvanized Z275 as standard; hot-dip after forming on request.
Can you supply purlins only?
Yes, cut to length, punched and bundled by building zone.
Do your stairs meet our code?
We build rise, going and guard rail heights to the code you name.
Secondary steel
Send purlin, stair or platform schedules
We price per piece and bundle by zone for site.