The structural line — residential and commercial
Preview — not yet in production Preview — read this firstProGuard is specified but not yet in production. This page is the specification we are building to, published in advance so you can evaluate it, quote against it and tell us if it does not suit your project. It is not available to order today.
| Post, outer size | 50 × 50 mm (1.97 × 1.97 in) |
|---|---|
| Post wall | 2.0 mm (0.079 in) |
| Material | Galvanised carbon steel |
| Grade | Q355D (GB/T 1591) |
| Finish | 5-stage powder coat, matte black; HDG option after welding |
| Post weight | 3.01 kg/m |
| Guard heights | 36 in and 42 in |
| Guard rail top rail | 50 × 50 × 1.5 mm, 6 ft max span |
| Cable top rail | 2 × 1 in × 2.5 mm, 4 ft max span |
| Base plate | 115 × 115 × 10 mm, 4 × Ø11 mm holes at 3.25 in centres, 5/8 in edge distance |
| Height | Safety factor | Load case |
|---|---|---|
| 36 in | 3.16 × | 200 lb concentrated, any direction (IRC R301.5) |
| 42 in | 1.34 × commercial case | 50 lb/ft uniform = 300 lb per post at 6 ft spacing (IBC 1607.9.1) |
We hold no ICC-ES evaluation report and no Intertek CCRR. Every figure here is our own engineering against published code requirements and published material minimums. It is not a third-party rating. The full working, with a live calculator, is on our Engineering & Code Compliance page.
Everyone quotes the 200 lb concentrated load. But IBC 1607.9.1 also applies a 50 lb per foot uniform load along the top rail, and at a 6 ft post spacing that is 300 lb per post — half again more than the concentrated load. That is the case ProGuard is sized against, and it is the real line between a residential guard and a commercial one.
On Q355 at the tolerance-minimum wall, 2.0 mm carries 1.34× against that governing commercial case and 2.01× against the concentrated one. 3.0 mm would give 1.91× and weigh 4.43 kg/m instead of 3.01 — 47% more steel for margin the code does not ask for. We would rather pass honestly than over-build expensively.
Chinese cold-formed hollow section carries a −10% wall tolerance, so a 2.0 mm nominal may arrive at 1.80. Every safety factor on this page is computed at nominal × 0.90 — not at the wall the drawing says.