ROUND FLAT WASHERS

Plain flat round washers are the most common type of washer.

They are thin, flat discs with a central hole, used primarily to distribute the load of a threaded fastener (like a bolt or screw) across a wider surface area.

Key Functions

  • Load Distribution: They prevent the bolt head or nut from digging into and damaging the material being fastened.
  • Surface Protection: Washers provide a smooth bearing surface, which is crucial when working with soft materials like wood, plastic, or thin sheet metal.
  • Clearance Bridging: They can bridge holes that are slightly larger than the fastener head or nut.
  • Spacing: They can act as simple spacers in industrial or domestic assemblies.

Common Standards and Variations

Flat washers are typically manufactured according to specific international standards that define their exact dimensions:

  • DIN 125
  •  ISO 7089
  • BS4320

Material Choices

  • Steel (Zinc-Plated): The most common choice for indoor applications, offering basic corrosion resistance.
  • Stainless Steel (A2/304 or A4/316): Essential for outdoor, marine, or chemical environments where rust prevention is critical.
  • Nylon/Plastic: Used for electrical insulation or when a non-conductive, lightweight spacer is needed.
ROUND FLAT WASHERS
MILD STEEL

MILD STEEL
STAINLESS STEEL A2 (304)

STAINLESS STEEL A2 (304)
STAINLESS STEEL A4 (316)

STAINLESS STEEL A4 (316)
NYLON

NYLON