Product Description
Metric A4 Marine Grade Stainless Steel Form B Flat Washers
A4 marine grade stainless steel Form B flat washers for use beneath nuts and bolt heads. Their flat bearing surface helps distribute the clamping load and protect the component surface during tightening.
The thin Form B profile is useful where assembly space is limited or a thinner washer is required. Choose the nominal washer size to suit your bolt or screw.
Technical Specifications
| Product Type | Flat washers |
|---|---|
| Washer Form | Form B — thin profile |
| Material | A4 marine grade stainless steel |
| Size System | Metric |
| Dimensional Reference | BS 4320 Form B |
Sizes and Dimensions
| Nominal Fastener Size | Internal Diameter | Outside Diameter | Thickness |
|---|---|---|---|
| M5 | 5.3mm | 10mm | 0.8mm |
| M6 | 6.4mm | 12.5mm | 0.8mm |
| M8 | 8.4mm | 17mm | 1mm |
| M10 | 10.5mm | 21mm | 1.25mm |
| M12 | 13mm | 24mm | 1.6mm |
| M14 | 15mm | 28mm | 1.6mm |
| M16 | 17mm | 30mm | 2mm |
| M18 | 19mm | 34mm | 2mm |
| M20 | 21mm | 37mm | 2mm |
Dimensions are nominal and subject to manufacturing tolerances. The nominal fastener size identifies the matching bolt or screw diameter; the washer hole is slightly larger to provide clearance. Please check with us before ordering if dimensions are critical.
Fitting Information
Select a washer with sufficient clearance around the fastener and enough outside diameter to support the joint. Position it flat beneath the nut or bolt head before tightening to the requirements of the assembly.
