TABLE 4

Imperial mild steel round washers are flat, low-carbon steel washers sized in fractional inches to accompany traditional imperial thread forms like UNC, UNF, BSW (Whitworth), and BSF.

These are categorised according to BS 3410 where washers are divided into specific tables that govern their dimensional scope and intended utility:

  • Table 4 (Light & Heavy Series): Features tightly constrained outer edge radii. These are specified strictly for compact, narrow clearance housings where the washer must sit tucked closely against a flange or step.
TABLE 4