Imperial Washer dimensions

WHAT IS THE PURPOSE OF WASHERS AND WHY ARE THEY USED?

[cite: 3]

LOAD DISTRIBUTION

[cite: 3]

The primary purpose of washers is to reduce the risk of damage and distribute the load of the threaded fastener with which they are used[cite: 3].

Threaded fasteners stress the material that they are driven into. For example, driving a screw into a wooden surface may crack the surface and damage the internal grain structure[cite: 3].

Not all materials require washers, but for wood and other softer materials, it is generally safer to incorporate washers to spread the load over a larger area[cite: 3].

SPACING

[cite: 3]

Washers can also be used as spacers[cite: 3]. Dimensions shown are in Inches, if you wish to convert to mm, please use our universal converter[cite: 3].

We also have information on Metric Washers[cite: 3].

IMPERIAL - FLAT WASHER DIMENSIONS - BS3410

[cite: 3]

Nominal Size	Inside Dia (d1)	Outside Dia (d2)	Thickness (h)
1/4"	0.281	0.625	0.048
5/16"	0.344	0.750	0.064
3/8"	0.406	0.875	0.064
7/16"	0.469	1.000	0.080
1/2"	0.531	1.125	0.080
5/8"	0.656	1.375	0.104
3/4"	0.781	1.625	0.104

IMPERIAL - SPRING WASHER DIMENSIONS - BS3410

[cite: 3]

Nominal Size	Inside Dia (d1)	Outside Dia (d2)	Section Size (w x t)
1/4"	0.255	0.489	0.109 x 0.062
5/16"	0.318	0.587	0.125 x 0.078
3/8"	0.382	0.684	0.141 x 0.094
7/16"	0.445	0.784	0.156 x 0.109
1/2"	0.508	0.884	0.172 x 0.125
5/8"	0.634	1.099	0.219 x 0.156
3/4"	0.760	1.324	0.266 x 0.188