M8 Coach Bolts Stainless Steel

M8 coach bolts DIN 603 have a thread diameter of 8mm and are commonly used in woodworking projects or when connecting timber to metal.

M8 Coach Bolt Dimensions

  • Thread Diameter: 8mm
  • Thread Pitch: 1.25mm
  • Head Diameter: 20.65mm (max)
  • Head Height: 4.88mm
  • Specification: DIN 603 

M8 Coach Bolts or M8 Carriage Bolts?

M8 coach bolts may also be known as M8 carriage bolts, dome head bolts, mushroom head bolts, or flat head bolts. They are ideal for use in the construction industry, for decking, and joist construction.

The square neck underneath the head acts as a compression locking device to prevent the bolt head turning during tightening of the nut. The domed head acts as partly a type of security device, because it only allows the bolt to be loosened from one side, and also as a decorative feature. When used on any outward facing area the smooth domed head prevents people catching themselves on the bolt head.

Stainless Steel M8 Coach Bolts 

We pride ourself on supplying stainless steel M8 coach bolts / M8 carriage bolts at highly competitive prices. If you can't find the length you are looking for, contact our team on our live chat for a quote for your desired size.

If you're not sure on size, browse our full range of stainless steel coach bolts.

Please Note: M8 coach bolts may come fully threaded or partially threaded depending on source of manufacture.

Not what you were looking for? Find stainless steel M8 coach screws DIN 571 here. 

16 products


M8 Coach Bolts – Stainless Steel (DIN 603 Carriage Bolts) | Fixabolt®

Secure from one side. Clean, round-head finish.

Fixabolt® M8 coach bolts (also known as carriage bolts) are a popular choice for builders, joiners, and landscapers who need reliable timber fixings with a neat appearance. Made to DIN 603 specifications, these bolts feature a rounded, low-profile head and a square neck that locks into the timber as the nut is tightened, making them perfect for applications where access is limited to one side.

Their 8mm thread diameter makes them ideal for medium-duty jobs where strength, corrosion resistance, and clean aesthetics are key.

Product Specifications

  • Thread Size: M8 (8mm diameter)
  • Standard: DIN 603 – mushroom head with square anti-rotation neck
  • Lengths Available: 40mm to 200mm

Material Grades:

A2 stainless steel (304) – excellent all-round protection against rust

Common Applications for M8 Coach Bolts

M8 coach bolts are perfect for:

  • Assembling timber frames and wall plates
  • Outdoor structures: pergolas, decking, sheds, and gates
  • Fixing metal brackets or hinges to wood
  • Garden furniture, fencing, and playground equipment
  • Anywhere you need a secure fixing with a smooth head finish

They’re designed to be installed into a pre-drilled hole; the square neck pulls into the timber to prevent spinning while the nut is tightened.

Shop related collections:

Stainless steel M6 coach bolts

Stainless steel M10 coach bolts

Stainless steel M12 coach bolts

Stainless steel M16 coach bolts

Why Order from Fixabolt®?

✔ High-quality stainless steel coach bolts

✔ Supplied with nuts – ready to use

✔ A2 for any environment

✔ Fast UK delivery and fair trade pricing

✔ DIN 603 compliant for consistent fit and strength

✔ Bulk quantity discounts for the trade

Fix it fast. Fix it right. Fix it with Fixabolt®.