Steel Bar Grating
Steel bar grating is manufactured from ASTM A-1011 mild carbon steel and is available in three distinct products: type “W” welded bar grating, type “SL” swage locked grating, and type “DT” dovetail pressure locked grating.
All products are available with bearing bar spacing ranging from 19/16” (1-3/16”) to 7/16” on center and cross bars at either 4” or 2” on center. Each product has a standard plain surface or may be specified with optional serrated or OnGrip™ slip-resistant surfaces.
Products are designed to service applications ranging from light pedestrian traffic to heavy duty vehicular loads. Finish options include bare steel, painted, hot dip galvanized, or specialty coatings.
Types of Steel Bar Grating
Type "W" Welded Steel Grating
Our most economical and durable products, type “W” welded steel gratings are manufactured by forge welding rectangular bearing bars and drawn cross bars. This welding process provides a positive, fused connection resulting in years of service under the most demanding conditions.
Spacing 19-W-4 is our most popular product and is recommended for most industrial flooring applications. With nearly 80% open area, 19-W-4 allows for the easy passage of dirt, debris, snow, and liquids and is essentially self-cleaning.
ADA conforming spacings 11-W-4 and 7-W-4 are commonly used in public areas. When specifying 11-W-4 products for ADA applications, 3/16” thick bearing bars must be specified.
Type "SL" Swage Locked Steel Grating
Type “SL” steel gratings are manufactured by inserting hollow tube cross bars into pre-punched holes in the bearing bars. The cross bars are then hydraulically compressed to form a positive mechanical connection. The cross bars are recessed below the top surface of the bearing bars providing a uniform and attractive architectural appearance.
Swage locking is a particularly efficient process for the production of ADA conforming gratings. Type 7-SL-4 with 3/16″ thick bearing bars provides a net 1/4″ clear opening between the bearing bars. This narrow opening is often preferred in public area applications where high heeled pedestrian traffic is likely and drainage is necessary.
Type "DT" Dovetail Pressure Locked Steel Grating
Type “DT” steel gratings have deep rectangular cross bars and are manufactured by inserting pre-punched bearing bars and cross bars into an “egg-crate” configuration and deforming the cross bars under intense hydraulic pressure.
The deep cross bars on type “DT” gratings make them popular for architectural applications such as sunshades and infill panels with the deeper cross bar serving as a distinct architectural accent.
Table of Spacings, Load Tables and How to Specify
About the Documents
The Steel Bar Grating Table of Spacings provides details and comparisons of standard 19 and 15 space grating panels as well as ADA compliant 11, 8, and 7 space gratings. The Table of Spacings is based upon a 3/16” thick bearing bar and .275” cross bars. Please contact us for details on custom bar thicknesses.
Steel bar grating load tables provide details about uniform loads, concentrated loads, and deflection for various spans related to supporting structures of the grating.
How to Specify Steel Bar Grating
1. Select type of Grating
• “W” for welded steel grating
• “DT” for dovetail pressure locked grating
• “SL” for swage locked grating
1. Select bar spacing from Table of Spacings
2. Select bearing bar size (consult load tables)
3. Specify grating surface: Plain, serrated, or applied grit
4. Specify banding or additional trim required
5. Specify finish options: no finish, painted, hot dip galvanized (per ASTM A-123), or other finish
6. Specify fasteners.
7. Specify cutouts if needed.
Surface Options
Plain Surface
Standard surface with excellent self-cleaning characteristics. Suitable for most applications.
Serrated Surface
Notched bearing bars provide increased slip resistance. Ideal for applications where moisture or fluids may be present on or near the walking surface.
OnGrip™ Surface
Applied grit surface for increased traction and slip resistance. Popular for applications in the public way.
Finish Options
Bare Steel
Mill finished carbon steel bars without additional coating. Will show discoloration from welding and fabrication. Subject to rusting.
Hot Dip Galvanized
Zinc coating applied in accordance with ASTM A123. Provides long lasting corrosion resistance.
Painted
One coat of manufacturer’s standard paint. Standard colors are black, red, and silver.
Other Finishes
Specialty coatings may be specified in a wide range of colors. Some options include powder coating, vinyl coating, enamel, or epoxy paints.
Banding
Banding is available to protect the open ends of the grating panel. During the banding process a metal flat bar is welded to the open ends of the grating panel. This process increases the transverse stiffness of the panel and provides a finished architectural appearance.
Banding should always be specified for the following applications:
- Removable grating panels – Banded ends provide additional worker safety during the handling of the panels.
- Vehicular load exposure – The band bar reduces impact stress by transferring loads to adjacent bearing bars thus increasing resistance to grating deformation caused by repetitive traffic.
Optional Load Banding is available and has welds at each bearing bar which helps distribute the load throughout the grating panel in addition to providing the uniform end finish(view details.)
Standard Trim Banding
The band bar that is welded to the end of the grating panel is the same height and thickness of the bearing bars. This provides a uniform appearance on all sides of the grating panel.
Trench Banding
The band bar is a smaller height than the bearing bars, and is therefore elevated above the bottom of the bearing bars. This banding application allows for greater drainage liquids will not be become trapped between the grating and the support structures.
Bar Grating Fabrication and Engineering
We offer complete engineering services from concept to production. This includes design consultation, technical manuals, CAD drafting, engineering certification, and custom design services.
Once your plans are approved, our fully trained production staff will transform stock panels into the custom components your project calls for. Our services include full layouts, saw cutting, flame or plasma cutting, welding, punching, banding, and finishing.
We also fabricate stair treads, frames, and install lifting devices as needed.
All panels are piece marked to match installation drawings that ship with your order.
Steel Bar Grating Welding & Fastener Information
Welding will provide a superior, permanent installation. Mechanical fasteners, also known as grating clips, are great options when steel bar grating will need to be removed or welding is not practical.
The recommended minimum weld pattern shown indicates the minimum fastener spacing for pedestrian applications. Vehicular applications typically require additional welding, size, and spacing as to be determined by the specifying authority.
Saddle Clips
Bent clips bridging two bearing bars are available in galvanized steel, stainless steel, or aluminum. Standard bolt holes are 5/16″. Bolts, screws, or other connecting hardware shall be supplied by others.
Countersunk Lands
The narrow spacing of close mesh grating allows for countersinking or milling of the bearing bars to support bolt shoulders. Flat head screws or self-drilling fasteners shall be supplied by others.
Weld Lugs
Plates, punched with holes and welded between the bearing bars, facilitate bolting to the supporting structure. Bolts, screws, or other connecting hardware shall be supplied by others.
“G” Clips
Mechanical fasteners installed from the top surface of the grating create a friction connection with the flange supporting the panel. “G” clips are easily installed without drilling or welding.
Countersunk Lands
The narrow spacing of close mesh grating allows for countersinking or milling of the bearing bars to support bolt shoulders. Flat head screws or self-drilling fasteners shall be supplied by others.
“J” Clips
Narrow formed clip captures one bearing bar when spacing is limited, frequently 11/16″ on center. Cap screws and other fastening hardware shall be supplied by others.
