40W4 Steel Grating Specifications (US & China Standard Comparison)

40W4 steel grating is a large-opening welded bar grating specification designed for maximum drainage and ventilation performance. Compared with standard 19W4 or 15W4 grating, 40W4 features much wider bearing bar spacing, making it ideal for light-duty industrial platforms and cooling systems.

As an experienced Steel Grating supplier, we manufacture 40W4 grating panels according to both ASTM/NAAMM standards and Chinese YB/T specifications for international engineering projects.

1. What Does 40W4 Mean?

• 40 = 40/16″ bearing bar spacing (2-1/2″ / 63.5 mm)
• W = Welded steel bar grating
• 4 = 4″ cross bar spacing (101.6 mm)
• Material: ASTM A36 carbon steel
• Surface: Plain, painted, or hot-dip galvanized (ASTM A123)

The 2-1/2 inch bearing bar spacing provides a significantly larger open area than 19W4 (1-3/16″) and reduces overall panel weight.

2. China Standard Equivalent

Under Chinese standard YB/T 4001.1, the closest metric equivalent is:

G303/60/100 (approximate match)

• 60 mm bearing bar spacing
• 100 mm cross bar spacing
• Material grade: Q235
• Galvanizing standard: GB/T 13912

Because China uses metric spacing increments, 63.5 mm is typically adjusted to 60 mm in practical production.

3. US vs China Specification Comparison

4. Key Advantages

• Maximum drainage capacity
• Excellent airflow performance
• Reduced weight and cost
• Suitable for light-load applications

5. Typical Applications

• Cooling tower platforms
• Water treatment walkways
• Industrial ventilation floors
• Non-pedestrian trench covers

Conclusion

40W4 steel grating is engineered for projects prioritizing ventilation and drainage rather than high structural load capacity. Engineers should confirm load and deflection requirements before selecting this large-opening specification.