Load Capacity
Closer bearing bar spacing (e.g., 15-W-2) provides more bars per unit width and typically higher load capacity for a given bar size. Tighter cross bar spacing adds rigidity.
Product Spacing Guide
Understanding the 19-W-4, 15-W-2 notation and how spacing affects use and performance.
Spacing Notation Format
Bar grating is typically specified using a notation such as 19-W-4 or 15-W-2. This format indicates:
- First number (19 or 15): Bearing bar spacing in 1/16-inch increments. 19 = 19/16″ (≈ 30 mm) center-to-center; 15 = 15/16″ (≈ 24 mm).
- Letter (W): Indicates welded construction. Other codes may denote press-locked (P) or other fabrication methods.
- Second number (4 or 2): Cross bar spacing in inches. 4 = 4″ (≈ 100 mm) center-to-center; 2 = 2″ (≈ 50 mm).
Examples: 19-W-4 = 30 mm bearing bar spacing, welded, 100 mm cross bar spacing. 15-W-2 = 24 mm bearing bar spacing, welded, 50 mm cross bar spacing.
GB vs. US Notation
US (ANSI/NAAMM): Uses inch-based notation (19-W-4, 15-W-2). First number = bearing bar spacing in 1/16"; second = cross bar spacing in inches.
GB (YB/T 4001.1): Uses metric notation such as W255/30/100 (bearing bar width 25×5 mm, 30 mm bearing spacing, 100 mm cross bar spacing) or W323/40/50. Equivalent to US formats—we can quote to either standard.
How Spacing Affects Use and Performance
Drainage and Open Area
Wider spacing (e.g., 19-W-4) allows more open area for drainage and airflow. Useful for trench covers, walkways over water, and ventilation.
Slip Resistance
Closer spacing can improve foot grip and reduce the risk of small objects falling through. Serrated surfaces add further slip resistance.
Application Selection
Heavy traffic, industrial platforms, and stair treads often use 15-W-2 or closer. Light-duty walkways and drainage may use 19-W-4 or similar.
Check load capacity for your spacing
Use our Load Tables or Load Calculator to verify suitability.