M20 Hex Bolts (Part Threaded)

Crafted to surpass the demands of construction, machinery, and automotive applications, these M20 hex bolts feature a thread diameter of 20mm and a head diameter of 30mm. 

Download M20 Hex Bolt specification sheet

M20 Bolt Dimensions

  • Thread Diameter: 20mm
  • Thread Pitch: 2.5mm
  • Head Width/Socket Size: 30mm
  • Head Depth: 12.85mm (max)
  • Thread Length ≤125mm: 46mm (min)
  • Thread Length 125mm - ≤200mm: 52mm (min)
  • Thread Length >200mm: 65mm (min)
  • Head Type: Hexagon

20mm Hexagon Bolts DIN 931

Conforming to DIN 931 standard, 20mm hex bolts feature a threaded portion designed for seamless integration with a compatible M20 nut. With their shank construction, these bolts have an increased load-bearing capacity, enabling them to resist forces in demanding environments. 

A2 Stainless Steel M20 Hex Bolts

Precision-engineered from A2 stainless steel, our M20 hex bolts demonstrate exceptional corrosion resistance, making them an ideal choice for outdoor use and applications exposed to moisture. 

Browse our full range of stainless steel hex bolts.

M20 Hex Bolts Stainless Steel (DIN 931 Part Thread) | Fixabolt®

For when maximum strength is non-negotiable.

Fixabolt® M20 hex bolts are built for high-load, heavy-duty applications where strength, stability, and reliability are essential. With a 20mm diameter and a part-threaded shank, these bolts conform to DIN 931 and are designed to resist shear and vibration in structural fixings, machinery, steelwork, and large-scale timber construction.

These aren’t your average bolts, they’re made for serious structural jobs that demand confidence in every turn of the wrench.

Product Specifications:

  • Size: M20 (20mm)
  • DIN 931 (partially threaded)
  • Hex head – compatible with spanners and sockets
  • Sizes: From 80mm to 300mm

These bolts feature a precision-machined shank for extra strength and a rolled thread for easy, clean installation.

If you need a fixing you can trust under real pressure, M20 bolts are the smart choice.

Why Buy M20 Bolts from Fixabolt®?

✔ Stainless steel in A2 and A4 grades

✔ Bulk discounts available for trade orders

✔ Tracked UK delivery — fast, reliable, and fully stocked

✔ Trusted by builders, engineers, and fabricators across the UK

✔ Easily pair with M20 washers and nuts — all stainless, all on the same page

Fixings for the heavy end of the job. Fixings from Fixabolt®.