SPEC-MM-BG01Industrial Standard

Bar Grating Specifications

Technical specification reference for bar grating systems

Reference Scope
ProfilesWelded & Press-Locked
ComplianceNAAMM Standards
Engineering Parameters

Standard bar grating specifications

Review standard bar dimensions, spacing designations, surface types, and NAAMM load design parameters for industrial floor grating.

Structural
Bearing bar
Primary load-carrying member

The main rectangular or I-bar running parallel to the span length that supports the design load.

Standard notation: 19-W-4 Designation

Notation indicates 19/16" (1-3/16") bearing bar spacing, welded construction (W), and 4" cross bar spacing. Available in heights from 3/4" to 2-1/2" and thicknesses from 1/8" to 1/4".

Lateral Stability
Cross bar
Perpendicular alignment member

Transverse twisted square or round bars forged or hydraulically locked perpendicular to the bearing bars.

Standard material: Twisted square / round rod

Maintains exact bearing bar alignment and transfers lateral forces without contributing to structural span load capacity.

Stock & Custom
Panel size
Stock and custom dimensional boundaries

Standard mill run panels or factory fabricated panels cut, banded, and shaped to project drawings.

Standard dimensions: 2'x20', 2'x24', 3'x20', 3'x24'

Stock widths of 24" and 36" with standard 20' or 24' lengths in the bearing bar direction. Custom cutting and banding available.

Center-to-Center
Bearing bar spacing
Center-to-center bar distance

Determines percentage of open area, pedestrian accessibility (ADA compliance), and unit weight.

Common centers: 19-space (1-3/16") & 15-space (15/16")

Available in 19-space (1-3/16"), 15-space (15/16"), 11-space (11/16"), and 7-space (7/16" close-mesh for high-heel and ADA walkways).

Centers
Cross bar spacing
Transverse spacing options

Standardized spacing intervals along the length of the bearing bar to fix open grid apertures.

Spacing standard: 4" center-to-center (2" optional)

4" on center is standard for welded industrial grating; 2" on center is applied for close-mesh or high-traffic pedestrian specifications.

Finish Profile
Serrated / smooth surface
Traction and slip-resistance profiles

Surface texture configuration engineered for workplace safety or smooth rolling equipment.

Options: Serrated (Anti-slip) / Plain (Smooth)

Serrated surfaces provide aggressive slip resistance in wet, oily, or icy walkways. Plain smooth surface suits interior utility platforms and rolling carts.

Structural Standards

Load considerations & NAAMM MBG 531

Load ratings are verified using the National Association of Architectural Metal Manufacturers (NAAMM) MBG 531 Bar Grating Manual. Capacities vary based on bearing bar geometry, clear span, and distribution method.

Bearing bar depth & thickness

Governs the section modulus and moment of inertia. Increased depth dramatically multiplies permissible load capacity across open spans.

Center-to-center spacing

Closer bearing bar centers (such as 15-space or 11-space) distribute concentrated point loads and vehicular wheel traffic more effectively.

Clear span distance

Load capacity decreases inversely with span length. Deflection limits are calculated under standard L/200 or 1/4" maximum service deflection.

NAAMM MBG 531 compliance

Manufactured strictly in accordance with the Metal Bar Grating Manual (NAAMM MBG 531) for uniform loads, concentrated loads, and fabrication tolerances.

Standard Welded Designation Example: 19-W-4 (1-3/16" Bearing Bar C-to-C, Welded, 4" Cross Bar C-to-C)
Explore welded grating options
Industrial Metal Solutions

Find the right bar grating for your project

Review standard bar spacing, bearing bar profiles, and load capabilities, or submit your architectural and industrial specifications directly to our fabrication team.