Square Plate Washers

Why use a square washer instead of a round one?

A square plate washer offers a wider footprint than a round flat washer plus flat sides that seat against wood grain or channel edges, which adds stability and helps stop bolt heads and nuts from pulling into softer material. The broad, thick body distributes clamping load and torque over a large area and can act as a shim so the fastener does not crush or deform the workpiece. That makes square plate washers a staple of timber framing, sill plates, deck ledgers, and anchor bolt connections. Hot dipped galvanized gives a thick, durable coating for the outdoor and wet exposure common in this kind of construction.

Why choose square plate washers

• Broad footprint: spreads load and prevents pull-through in wood.
• Flat sides: seat against wood grain and channel edges for stability.
• Shim action: thick body protects the surface from crushing.
• Galvanized: durable coating for outdoor construction.

Common applications for square plate washers

• Timber framing and heavy wood construction
• Sill plates and anchor bolt connections
• Deck ledgers and structural wood joints
• Outdoor and treated-lumber fastening

For angled flanges, see square beveled washers, and browse every option on the main square washers category.

Square Plate Washers FAQ

What does a square washer do compared to a round flat washer?

It provides a wider footprint with flat sides that seat against wood grain or channel edges, helping reduce pull-through and rotation while spreading load.

Why are square plate washers used in wood construction?

Their broad, thick body spreads clamping load and acts as a shim, so bolts and nuts do not pull into or crush the timber.

Are galvanized square plate washers good outdoors?

Yes. The hot dipped galvanized coating is thick and durable, suited to the outdoor and treated-lumber exposure common in construction.