Steel Washer
- Round steel flat washer for general bolted connections
- Spreads nut / head bearing where a square washer is not required
- Hot-dip galvanized to ASTM A-153
- Metric M12–M24 and imperial 1/2–3/4 in
- Flat and heavy-duty thicknesses
- For equipment, bracket and structural fixing
Technical Specifications
| Catalog | For Bolt | OD (mm) | Thickness (mm) | Hole (mm) | Surface |
|---|---|---|---|---|---|
| RAX-STW-M12 | M12 | 24 | 2.5 | 13 | HDG |
| RAX-STW-M16 | M16 | 30 | 3.0 | 17 | HDG |
| RAX-STW-M20 | M20 | 37 | 3.0 | 21 | HDG |
| RAX-STW-M24 | M24 | 44 | 4.0 | 25 | HDG |
| Custom | Other sizes / stainless / heavy-duty — send your bolt spec | ||||
Application & Installation
Where it is used
The round steel flat washer spreads the bearing of a hex bolt head or nut on general structural and equipment connections — the standard round washer used wherever the square pole-line washer is not specified. Supplied galvanized in metric and imperial sizes, flat and heavy-duty.
Installation sequence
- Select the washer for the bolt size.
- Place it under the head and / or nut.
- Run the nut up so the washer seats flat.
- Tighten so bearing spreads across the washer.
- Add a spring / lock washer where vibration is a concern.
Buyer’s Guide: Steel Washer
1. What a Steel Washer Does
A round steel flat washer sits under a bolt head or nut to spread the clamping load and protect the surface. It is the everyday washer for hex-bolt structural and equipment connections, where the square ANSI pole-line washer is not called for.
2. Round vs Square
Round washers suit hex bolts on steel structures and equipment; the square washer is for pole-line machine bolts on timber and arms. Use the form that matches the fastener and member.
3. Flat vs Heavy-Duty
Standard flat washers cover general fixing; heavy-duty (thicker) washers spread higher loads or bridge slotted / oversize holes. Pick the thickness for the bearing the joint needs.
4. Sizing to the Bolt
Match the hole to the bolt (M12–M24 / 1/2–3/4 in) and the OD to the bearing area. Pair with a spring or lock washer where vibration could loosen the nut.
5. Galvanizing
Hot-dip galvanized to ASTM A-153 to match the bolt; stainless options on request for severe environments.
6. Pairing
Used with hex bolts and nuts on towers, frames, equipment and brackets. Order with the bolts so sizes and coating match.
