Simfix

M8 Flat Washer, Form C 25 Pack BS4320-C A4 Stainless Steel

SKU 125CA4084PK25-SIM
1000+ in stockReady to dispatch
£2.15
Pack size:
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M8 flat washer (Form C, large OD) in A4 stainless steel (316 marine grade) to BS4320-C. The large outer diameter spreads load over a wider area than a standard Form A washer - useful for oversized holes and soft parent materials. A4 (316) resists saltwater and chloride attack for coastal and marine use. Free next-day UK delivery on orders over £50.
£2.15

M8 flat washer (Form C, large OD) in A4 stainless steel (316 marine grade) to BS4320-C. The large outer diameter spreads load over a wider area than a standard Form A washer - useful for oversized holes and soft parent materials. A4 (316) resists saltwater and chloride attack for coastal and marine use. Free next-day UK delivery on orders over £50.
  • M8 flat washer Form C marine grade 316 BS 4320
  • BS 4320 Form C flat washer M8 A4 marine grade stainless steel, side profile
  • Flat washer face-on - M8 A4 stainless Form C BS 4320
  • Flat Washer, Form C in a real-life marine application. The broad outside diameter spreads load over softer surfaces.
  • Simfix product label - 125CA4084PK25-SIM
  • Simfix product label - 125CA4084PK100-SIM
M8 flat washer Form C marine grade 316 BS 4320
BS 4320 Form C flat washer M8 A4 marine grade stainless steel, side profile
Flat washer face-on - M8 A4 stainless Form C BS 4320
Flat Washer, Form C in a real-life marine application. The broad outside diameter spreads load over softer surfaces.
Simfix product label - 125CA4084PK25-SIM
Simfix product label - 125CA4084PK100-SIM
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M8 flat washer Form C marine grade 316 BS 4320 BS 4320 Form C flat washer M8 A4 marine grade stainless steel, side profile Flat washer face-on - M8 A4 stainless Form C BS 4320 Flat Washer, Form C in a real-life marine application. The broad outside diameter spreads load over softer surfaces. Simfix product label - 125CA4084PK25-SIM Simfix product label - 125CA4084PK100-SIM
M8 flat washer Form C marine grade 316 BS 4320 BS 4320 Form C flat washer M8 A4 marine grade stainless steel, side profile Flat washer face-on - M8 A4 stainless Form C BS 4320 Flat Washer, Form C in a real-life marine application. The broad outside diameter spreads load over softer surfaces. Simfix product label - 125CA4084PK25-SIM Simfix product label - 125CA4084PK100-SIM

This M8 Form C flat washer is manufactured to BS4320-C in A4 stainless steel (316 marine grade). BS4320 Form C specifies a large outer diameter washer, providing a significantly wider bearing surface than a standard DIN 125-A Form A washer for the same bolt size. A4 (316) grade gives superior resistance to chloride and saltwater attack compared with A2 (304), making this the correct choice for coastal, marine, pool, and chemical environments where load distribution and corrosion resistance are both critical.

Typical applications

  • Marine and coastal installations - boat fittings, pier fixings, jetty hardware
  • Swimming pool surrounds, water treatment plant, and pump assemblies
  • Timber decking and fencing in wet or coastal conditions
  • Chemical plant, food processing, and washdown environments

Available in packs of 25 to 100, with free next-day UK delivery on orders over £50 and 30-day no-quibble returns.

*Photos, diagrams and other images are for illustration only and may not show the exact item supplied. Simfix reserves the right to alter or replace any photo, diagram or image at any time at its sole discretion.

**Orders that cannot be split will be rounded up to the next full pack or box quantity.

Simfix reserves the right to change quantities, stock levels and prices at any time. We accept no liability for the accuracy of dimensional data, DIN/ISO references, technical data, customs tariff codes or EAN barcodes.

Fastener styleForm C flat washer
StandardBS4320-C
MaterialA4 stainless steel (316)
Property classA4-50/70
Thread sizeM8
Head typeN/A
Surface finishPlain (no plating)
HS commodity code7318220091
Recommended useMarine

RoHS and REACH compliant.

How do I choose between A2 and A4 stainless steel?

A2 (304) stainless steel suits most indoor, outdoor and workshop jobs. Choose A4 (316) marine grade for coastal, marine, poolside or other chloride-rich environments.

How do I make sure I order the right size?

Check the size in the product title and the standard, material and dimensions in the Product Specification tab. In M8 x 30, M8 is the thread diameter and 30 is the length in millimetres. See our size guide if you need more help.

When will my order arrive?

Orders placed before 4pm Monday-Friday are typically dispatched the same working day and every order is tracked. Next-day delivery is free over £50, or £5.50 below that threshold. Full options are shown at checkout.

What if I order the wrong item?

Email contact@simfix.com within 30 days of delivery with your order number. We will help arrange a refund or replacement. See our refunds information for the full process.

Is checkout secure?

Yes. Checkout is protected by SSL encryption and payments are processed through Shopify's secure checkout and supported payment providers. Simfix does not store your full card details.

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