Square Plate Washers

A square plate washer is a large-format flat washer with a square profile and a central bolt hole, providing a significantly greater bearing area than a standard round washer under bolt heads and nuts in timber construction, fence and gate installation, and structural bolting applications. At the DIY Hardware Store, our square plate washers are available in the zinc-plated steel sizes most commonly used alongside coach bolts, hex bolts, and coach screws in outdoor and structural timber work.

The large bearing area of a plate washer is particularly valuable in timber connections where a standard round washer would pull into the soft grain under the clamping force of a tightened bolt. By spreading the load across a larger area, the plate washer reduces the contact pressure on the timber surface, preventing embedding and maintaining the clamping force of the connection over time as the timber dries and settles. They're the standard specification for structural connections in fencing, timber framing, and gate hardware.

Available in zinc-plated steel in the bolt hole sizes and plate dimensions most commonly used for M8, M10, and M12 structural bolting applications at the DIY Hardware Store.

  • Large square plate distributes bolt load across wide timber area
  • Prevents washer pull-through and embedding in soft timber
  • Maintains clamping force as timber dries and settles
  • Standard for fencing, timber framing, and gate connections
  • Zinc-plated steel for outdoor and structural use
  • Sizes for M8, M10, and M12 structural bolting