Steel grating is an open grid of bearing bars and cross bars that carries foot traffic and equipment loads while letting light, air, water and debris pass through. Choosing the right one comes down to four questions: how the grid is assembled, how heavy the load is, what the walking surface must do underfoot, and what environment the installation faces.
What Steel Grating Is and Where It Is Used
Grating is manufactured by pressure locking, welding or riveting the cross bars to a series of parallel bearing bars. The bearing bars carry the load and the cross bars hold the pitch and spread the load between them, which produces a stiff panel from a relatively small amount of steel. Typical installations include industrial platforms and walkways, catwalks, stair treads, trench and drainage covers, mezzanine floors and ventilation grilles, where the open area gives airflow and drainage while the structure still carries people or equipment.
How the Three Manufacturing Methods Differ
Pressure-locked grating - the cross bars are pressed into notches cut in the bearing bars under high pressure, forming a permanent mechanical joint without any welding. It is the usual choice for platforms and walkways, and it suits installations where a clean, weld-free appearance matters.
Welded grating - the cross bars are resistance welded to the bearing bars, producing a rigid panel for industrial floors and higher load duty. The weld line stays visible, and this type is the stiffest of the three.
Riveted grating - pressed cross bars are held by rivets through the bearing bars, giving a strong assembly that can be repaired on site, used for heavy duty and long span applications.
Grating Types and Typical Configurations
| Type | Bearing bar | Typical use |
|---|---|---|
| Pressure-locked | Flat or serrated | Platforms, walkways, catwalks |
| Welded | Flat, heavier section | Industrial floors and high load duty |
| Serrated | Notched top edge | Slip resistance in wet or oily areas |
| Stair tread | Serrated bar with nosing | Stairs and access routes |
| Heavy duty | Thick bar, close pitch | Vehicle, trolley and pallet loads |
Serrated grating is produced by notching the top edge of the bearing bar, which gives a mechanical grip underfoot without adding a separate anti-slip layer. Stair treads combine a serrated bar with a solid nosing that protects the front edge and improves visibility of the step.
Bearing Bar Size, Pitch and Load Capacity
Load capacity is governed by the depth and thickness of the bearing bar, the clear span between supports, the bearing bar pitch and the way the panel is fixed down. In practice the bar size and pitch are read from the published load table for the actual span under the design uniform or concentrated load, and an appropriate safety factor is applied on top. As a working range, bearing bars run from roughly 20 x 3 mm for light walkways and covers up to 60 x 5 mm and larger for heavy duty service, with close pitch used where small wheels, pallets or point loads dominate. Cross bars are normally twisted square bar in 6 mm or 8 mm sections; the depth of the bearing bar, not the cross bar, does most of the load carrying work. Deflection often governs the design of a walkway before stress does, because an over-flexible panel feels unsafe even when it is strong enough.
Materials, Coatings and Verification
Carbon steel - bearing bars in a standard structural or forming grade; the most common and economical basis for industrial grating.
Hot dip galvanized finish - applied to ASTM A123 or EN ISO 1461, with the coating class and minimum local thickness specified for the service environment. It is the standard protection for outdoor walkways, platforms and trench covers.
Stainless steel - used for aggressive chemical, marine or hygienic areas where a zinc coating would not survive the service life.
Inspection - panel dimensions, bearing bar pitch, straightness and the quality of the weld or pressure lock are checked on the delivered lot against the approved drawing before the panels are fixed in place.
Packing and marking - panels are bundled and marked by type and size so that, on a site with several grating areas, the correct panels reach the correct opening without being mixed.
FAQ
Q: How do I choose between pressure-locked and welded grating?
Pressure-locked grating is the normal choice for walkways and platforms, while welded grating is used where higher loads or a more rigid floor are required. The load table for the actual span decides the point at which welded construction becomes the better option.
Q: When should serrated grating be used instead of plain grating?
Wherever the walking surface can become slippery. Wet, oily, greasy or icy conditions, ramps, and stair treads all call for serrated bearing bars or an applied anti-slip surface.
Q: What factors decide the load a panel can carry?
Bearing bar depth and thickness, the clear span between supports, the bearing bar pitch and the fixing detail. All four are entered into the load table together, because a short span with a light bar can outperform a longer span with a heavy one.
Q: Is a safety factor needed on the published load?
Yes. The design load is checked against the load table with the safety factor required by the governing design code, and deflection limits are usually applied as well so that the finished walkway feels solid underfoot.
Q: Is hot dip galvanizing suitable for outdoor grating?
It is the standard finish for outdoor work. The coating class and minimum local thickness are specified for the environment, and the zinc coating protects both faces and the cut edges of the bars.
Q: Can panels be supplied to match a drawing?
Yes. Grating is routinely supplied cut to size with nosing, cut-outs, hinged sections and fixing details, and the finished lot is checked against the approved drawing before it is packed.
