Grate-Lock® Stair Treads

grate-lock-safety-grating, crossover Grate-Lock® Safety Grating Stair Treads

Grate-Lock® safety grating stair treads have many benefits including versatility, fast and easy installation, economical and safer dimpled surface. Marco Specialty Steel supplies and fabricates Grate-Lock® stair treads for many industries including oil & gas, waste & sewage, mining, OEM and industrial plants.

Stair treads are available in standard and custom designs.


Grate-Lock® Stair Tread Design and Selection Table


U – Uniform Load (lb/sq. ft) C – Concentrated Load (lb)
(1) Intermediate stringer recommended for spans over 4

Grate Lock Plank Sections

Diagram Detail:


  • Widths: 3″, 4″(*), 6″, 9″, 12″
  • Heights: 1 1/2″ (**), 2 1/2″, 3″(*), 4″(*)
  • Gauges: 18, 16(*), 14
  • Lengths: 12-0″, 20′-0″ ,24′-0″
Note: 3″ & 4″ filler plank is solid. FM interlock.
(*) Special quote required.
(**) The 1 1/2″ product is available only in 12′-0″ length and differs in side channel detail and loading capability.











Click here to print Grate-Lock® Stair Tread Design and Selection Table

Contact Marco Specialty Steel today to learn more about our Grate-Lock® stair tread products.

Marco Specialty Steel: Quality. Speed. Reliability.