Fixed ladder specifications decide whether a climb passes an audit or fails it. Get the steel grade, load rating, coating, and rung spacing right, and the ladder outlasts the building. Get one figure wrong, and an inspector can stop the job. These are the numbers we quote every week from our 8,000 m² factory in Shijiazhuang, an ISO 9001:2015 plant shipping factory-direct to 50+ countries.
No trader markup. No rounded-off guesses. Every value below comes off a real shop drawing, backed by material certificates, weld reports, and load-test data.
1. Material Grades: Q235B, SS304, SS316
Three grades cover almost every fixed ladder we ship. The choice comes down to the site, not the budget alone.
- Q235B carbon steel — the workhorse. Yield strength 235 MPa, hot-dip galvanized for outdoor duty. Strong, affordable, right for most dry or sheltered jobs.
- SS304 stainless — for coastal air, food plants, and washdown areas. It resists rust with no coating.
- SS316 stainless — adds molybdenum for chloride and marine exposure. Chemical plants and offshore decks specify it.
In our workshop we cut Q235B for roughly of fixed ladder orders, and keep SS304 or SS316 for corrosive duty. Every batch is mill-certified, with the heat number traceable back to the coil. Still choosing a type? Our guide to fixed ladders compares configurations side by side.
2. Coating and Corrosion Protection
Coating thickness decides how long a carbon-steel ladder survives outdoors. We galvanize to EN ISO 1461.
- Standard hot-dip galvanizing (HDG): µm average zinc, inside the EN ISO 1461 band of about 70–85 µm for this section thickness.
- Coastal or aggressive exposure: we lift the spec to 85–115 µm for longer service life.
- Powder coat or duplex finishes go over the zinc when colour or extra protection matters.
Coating thickness is read with a magnetic gauge at several points on each ladder. The readings go into the QC log that travels with the order. Third-party checks by SGS, TÜV, or Bureau Veritas are available on request.
3. Load Rating and Structural Capacity
A fixed ladder is rated by the force a single rung and the stringers can carry. The headline figures:
- Each rung carries a 1.5 kN concentrated point load with no permanent set, per EN ISO 14122-4.
- OSHA 1910.23 expects every rung, cleat, and step to hold at least 250 lb (about 1.1 kN) as a single concentrated load.
- Stringers are sized so the stile assembly resists both climbing and fall-arrest reaction loads with a safety margin.
We pull a sample from each production batch and run a tensile and rung-load test before the lot leaves the floor. Anything that misses spec is scrapped, not shipped. For the full weight picture, see our note on fixed ladder weight capacity.
4. Rung Spacing and Geometry
Geometry is where compliance slips most often. Fixed ladder rungs and their spacing follow OSHA 1910.23 and EN ISO 14122-4, and the two standards line up closely.
- Fixed ladder rung spacing: 250–300 mm centre-to-centre, uniform top to bottom (EN ISO 14122-4; OSHA caps it at 12 in / 305 mm).
- Rung diameter: 20–30 mm round or square bar, slip-resistant on every step.
- Clear width between stringers: 400–600 mm; 400 mm is the practical minimum for a comfortable climb.
- Toe clearance behind the rung: at least 150 mm so a boot sits fully on the bar.
Keep the fixed ladder rung spacing uniform and the toe clearance right, and the rest of the layout tends to fall into place. We detail the climb-height geometry in our fixed ladder dimensions reference.
5. Standard Sizes and Cage Dimensions
Most projects land on a familiar set of fixed ladder standard dimensions. We build to these unless a drawing says otherwise.
- Ladder width: 400–600 mm between stringers.
- Standoff from wall: about 150–200 mm to the centre of the rung.
- Safety cage, where the climb height triggers one: hoops at roughly 1,200–1,500 mm vertical pitch, tied by vertical straps.
- Cage inside diameter: about 700 mm, keeping the climber within reach of the hoops.
- Walk-through rails at a landing extend 1,070 mm above the step-off.
Note one shift in the rules. Under OSHA 1910.23, new fixed ladders over 24 ft (7.3 m) must use a ladder safety system or personal fall arrest, not a cage. For tall climbs we usually fit a vertical fixed access ladder with a fall-arrest rail, so the fixed ladder standard dimensions then follow the rail maker's spacing as well.
6. Specification Quick-Reference Table
One sheet, all the fixed ladder specifications in a single view. Pin it to the drawing.
| Parameter | Typical Specification | Standard / Note |
|---|---|---|
| Material | Q235B / SS304 / SS316 | Mill-certified, heat-traceable |
| Rung load (EU) | 1.5 kN point load | EN ISO 14122-4 |
| Rung load (US) | 250 lb (~1.1 kN) | OSHA 1910.23 |
| Rung spacing | 250–300 mm | Uniform; ≤305 mm (OSHA) |
| Rung diameter | 20–30 mm | Slip-resistant |
| Ladder width | 400–600 mm | Between stringers |
| Toe clearance | ≥150 mm | Behind rung |
| HDG coating | µm (70–85 typical) | EN ISO 1461 |
| Cage hoop pitch | 1,200–1,500 mm | Where a cage applies |
| Walk-through rail | 1,070 mm above landing | Step-off safety |
One project to anchor the numbers. A client in ordered SS304 fixed ladders for a new line. They needed EN ISO 14122-4 sign-off and SGS-witnessed load tests. We supplied the full document pack — material certificates, weld maps, coating logs, and test reports — and the batch cleared the third-party audit on the first visit.
That is the point of nailing the fixed ladder specifications before steel is cut: the paperwork has to match the part. We welcome factory audits, and the certificates ship with every order. Send your height and local code, and our engineers return a drawing, load rating, coating spec, and factory-direct quote — no middleman. Start with our fixed ladder guide or our OSHA 1910.23 breakdown, then talk to our team.