Designs and Specifications of Steel Grating for Stair Treads

Steel grating with weather resistance performance and solid structure is widely used in chemical, petroleum, sewage treatment plants and other fields for stair treads, platform and walkway applications. You can refer to the product page of stair tread steel grating to know more bout the gratings. Here, we will introduce the project design of steel grating used in the stair treads applications.

Length of steel grating stair treads

• Common length. 700 mm, 800 mm and 900 mm are the most widely used and popular width.
• Maximum length is 1200 mm. If there are several people passing at the same time in double direction or it is used as the escape line for workers, the stair tread width should choose 1200 mm.
• Minimum length is 600 mm. 600 mm width is suitable for the stair treads for single person passing.

Specifications of steel grating for stair treads

• Steel grating type: welded steel grating and press bar grating.
• Bearing bar type: flat bar and I bar.
• Bearing bar pitch: 20 mm, 30 mm or 40 mm.
• Cross bar pitch: 50 mm or 100 mm.
• Nosing type: checker plate, strip plate and hole plate.
• Surface treatment: galvanized or anti-corrosion painted.
• Bearing load: 1.5 kN.
• Deflection: no larger than 1/500 of span.
• Deflection testing method:
  • Span no larger than 1200 mm: press 1.5 kN load at the 100 mm × 100 mm area.
  • Span larger than 1200 mm: press 1.5 kN at the symmetrical 600 mm position.
• End plate size and hole size of bolted fixing grating: refer to Table 1.
• Flat bar detailed specifications: refer to Table 2.
• I bar detailed specifications: refer to Table 3.
• Press-locked steel grating specification: refer to Table 4.

STD-06: End plate size and hole pitch.

Tolerance of steel grating for stair treads

• Length tolerance: +0/-0.04 mm.
• Width tolerance: ± 3 mm.
• Vertical tolerance. Vertical tolerance angle is no larger than 25°.

Steel grating tolerance for stair treads.

Types of steel grating stair treads:

• Type 1. Weld fixing, banded ends without nosing.
• Type 2. Bolted fixing, holed end plates without nosing.
• Type 3. Welded fixing, banded ends with nosing.
• Type 4: Bolted fixing, holed end plates with nosing.

STD-01: Type 1: Weld fixing, banded ends without nosing.

STD-02: Type 2: Bolted fixing, holed end plates without nosing.

STD-03: Type 3: Welded fixing, banded ends with checker plate nosing.

STD-04: Type 4: Bolted fixing, holed end plates with nosing.

Connection of stair treads and ladder beam.

• Bolt connection. It adopts thickening end plate for welding and pre-holed on the end plate and fixed by bolts and nuts. It is recycled for other applications or places.
• Welded connection. It is difficult to uninstall but more economical and firmer than bolted connection.

STD-05: Welded and bolted connection of stair treads.

STD-07: Steel grating for indoor stair tread.

STD-08: Steel grating for outdoor stair treads.