Special Offers
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6.3 X 25 Hex Head Self Drilling Screw DIN 7504-K A2 Stainless Steel
In stockRRP From £11.21 -
M8 Flat Washer, Form A DIN 125-A A2 Stainless Steel
In stockRRP From £2.69 -
M8 Nylon Insert Nut DIN 985 A2 Stainless Steel
In stockRRP From £3.23 -
M10 Hexagon Full Nut DIN 934 A2 Stainless Steel
In stockRRP From £3.99
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1" UNC X 4" Hex Bolt A4 Stainless Steel
In stockThis 1" UNC x 4" part threaded hex bolt is manufactured in A4 stainless steel (316 grade). The unthreaded shank sits in the bearing hole rather than the thread, locating the joint accurately and presenting a...RRP From £59.47RRP From £59.47 -
1" BSW X 4.1/2" Hex Head Bolt A2 Stainless Steel
Out of stockThis 1" BSW x 4.1/2" part threaded hex bolt is manufactured in A2 stainless steel (304 grade). The unthreaded shank sits in the bearing hole rather than the thread, locating the joint accurately and presenting a...RRP From £35.45RRP From £35.45 -
M8 X 95 Hexagon Head Bolt DIN 931 A2 Stainless Steel
In stockThis M8 x 95mm part threaded hex bolt is manufactured to DIN 931 in A2 stainless steel (304 grade). DIN 931 specifies a hex head bolt with a plain shank beneath the head and thread over...RRP From £7.77RRP From £7.77 -
M8 X 90 Hexagon Head Bolt DIN 931 A4-80 A4 Stainless Steel
In stockThis M8 x 90mm part threaded hex bolt is manufactured to DIN 931 in A4 stainless steel (316 grade). DIN 931 specifies a hex head bolt with a plain shank beneath the head and thread over...RRP From £14.10RRP From £14.10 -
M8 X 90 Hexagon Head Bolt DIN 931 A4-70 A4 Stainless Steel
In stockThis M8 x 90mm part threaded hex bolt is manufactured to DIN 931 in A4 stainless steel (316 grade). DIN 931 specifies a hex head bolt with a plain shank beneath the head and thread over...RRP From £13.13RRP From £13.13 -
M8 X 85 Hexagon Head Bolt DIN 931 A2 Stainless Steel
In stockThis M8 x 85mm part threaded hex bolt is manufactured to DIN 931 in A2 stainless steel (304 grade). DIN 931 specifies a hex head bolt with a plain shank beneath the head and thread over...RRP From £4.39RRP From £4.39 -
M8 X 85 Hexagon Head Bolt DIN 931 A4 Stainless Steel
In stockThis M8 x 85mm part threaded hex bolt is manufactured to DIN 931 in A4 stainless steel (316 grade). DIN 931 specifies a hex head bolt with a plain shank beneath the head and thread over...RRP From £13.98RRP From £13.98 -
M8 X 90 Hexagon Head Bolt DIN 931 A2 Stainless Steel
In stockThis M8 x 90mm part threaded hex bolt is manufactured to DIN 931 in A2 stainless steel (304 grade). DIN 931 specifies a hex head bolt with a plain shank beneath the head and thread over...RRP From £3.79RRP From £3.79 -
M8 X 80 Hexagon Head Bolt DIN 931 A4-80 A4 Stainless Steel
In stockThis M8 x 80mm part threaded hex bolt is manufactured to DIN 931 in A4 stainless steel (316 grade). DIN 931 specifies a hex head bolt with a plain shank beneath the head and thread over...RRP From £9.96RRP From £9.96 -
M8 X 75 Hexagon Head Bolt DIN 931 A4-80 A4 Stainless Steel
In stockThis M8 x 75mm part threaded hex bolt is manufactured to DIN 931 in A4 stainless steel (316 grade). DIN 931 specifies a hex head bolt with a plain shank beneath the head and thread over...RRP From £13.26RRP From £13.26 -
M8 X 75 Hexagon Head Bolt DIN 931 A4-70 A4 Stainless Steel
In stockThis M8 x 75mm part threaded hex bolt is manufactured to DIN 931 in A4 stainless steel (316 grade). DIN 931 specifies a hex head bolt with a plain shank beneath the head and thread over...RRP From £8.08RRP From £8.08 -
M8 X 75 Hexagon Head Bolt DIN 931 A2 Stainless Steel
In stockThis M8 x 75mm part threaded hex bolt is manufactured to DIN 931 in A2 stainless steel (304 grade). DIN 931 specifies a hex head bolt with a plain shank beneath the head and thread over...RRP From £4.08RRP From £4.08 -
M8 X 70 Hexagon Head Bolt DIN 931 A4-80 A4 Stainless Steel
In stockThis M8 x 70mm part threaded hex bolt is manufactured to DIN 931 in A4 stainless steel (316 grade). DIN 931 specifies a hex head bolt with a plain shank beneath the head and thread over...RRP From £6.47RRP From £6.47 -
M8 X 70 Hexagon Head Bolt DIN 931 A2 Stainless Steel
In stockThis M8 x 70mm part threaded hex bolt is manufactured to DIN 931 in A2 stainless steel (304 grade). DIN 931 specifies a hex head bolt with a plain shank beneath the head and thread over...RRP From £3.88RRP From £3.88 -
M8 X 70 Hexagon Head Bolt DIN 931 A4-70 A4 Stainless Steel
In stockThis M8 x 70mm part threaded hex bolt is manufactured to DIN 931 in A4 stainless steel (316 grade). DIN 931 specifies a hex head bolt with a plain shank beneath the head and thread over...RRP From £8.75RRP From £8.75 -
M8 X 65 Hexagon Head Bolt DIN 931 A4-80 A4 Stainless Steel
In stockThis M8 x 65mm part threaded hex bolt is manufactured to DIN 931 in A4 stainless steel (316 grade). DIN 931 specifies a hex head bolt with a plain shank beneath the head and thread over...RRP From £11.83RRP From £11.83 -
M8 X 65 Hexagon Head Bolt DIN 931 A2 Stainless Steel
In stockThis M8 x 65mm part threaded hex bolt is manufactured to DIN 931 in A2 stainless steel (304 grade). DIN 931 specifies a hex head bolt with a plain shank beneath the head and thread over...RRP From £6.50RRP From £6.50 -
M8 X 65 Hexagon Head Bolt DIN 931 A4-70 A4 Stainless Steel
In stockThis M8 x 65mm part threaded hex bolt is manufactured to DIN 931 in A4 stainless steel (316 grade). DIN 931 specifies a hex head bolt with a plain shank beneath the head and thread over...RRP From £8.51RRP From £8.51 -
M8 X 60 Hexagon Head Bolt DIN 931 A4-80 A4 Stainless Steel
In stockThis M8 x 60mm part threaded hex bolt is manufactured to DIN 931 in A4 stainless steel (316 grade). DIN 931 specifies a hex head bolt with a plain shank beneath the head and thread over...RRP From £8.10RRP From £8.10 -
M8 X 55 Hexagon Head Bolt DIN 931 A4-70 A4 Stainless Steel
In stockThis M8 x 55mm part threaded hex bolt is manufactured to DIN 931 in A4 stainless steel (316 grade). DIN 931 specifies a hex head bolt with a plain shank beneath the head and thread over...RRP From £7.58RRP From £7.58 -
M8 X 55 Hexagon Head Bolt DIN 931 A4-80 A4 Stainless Steel
In stockThis M8 x 55mm part threaded hex bolt is manufactured to DIN 931 in A4 stainless steel (316 grade). DIN 931 specifies a hex head bolt with a plain shank beneath the head and thread over...RRP From £6.87RRP From £6.87 -
M8 X 55 Hexagon Head Bolt DIN 931 A2 Stainless Steel
In stockThis M8 x 55mm part threaded hex bolt is manufactured to DIN 931 in A2 stainless steel (304 grade). DIN 931 specifies a hex head bolt with a plain shank beneath the head and thread over...RRP From £3.08RRP From £3.08 -
M8 X 50 Hexagon Head Bolt DIN 931 A4-80 A4 Stainless Steel
In stockThis M8 x 50mm part threaded hex bolt is manufactured to DIN 931 in A4 stainless steel (316 grade). DIN 931 specifies a hex head bolt with a plain shank beneath the head and thread over...RRP From £6.67RRP From £6.67 -
M8 X 50 Hexagon Head Bolt DIN 931 A4-70 A4 Stainless Steel
In stockThis M8 x 50mm part threaded hex bolt is manufactured to DIN 931 in A4 stainless steel (316 grade). DIN 931 specifies a hex head bolt with a plain shank beneath the head and thread over...RRP From £7.81RRP From £7.81 -
M8 X 45 Hexagon Head Bolt DIN 931 A4-70 A4 Stainless Steel
In stockThis M8 x 45mm part threaded hex bolt is manufactured to DIN 931 in A4 stainless steel (316 grade). DIN 931 specifies a hex head bolt with a plain shank beneath the head and thread over...RRP From £7.27RRP From £7.27
Part threaded hexagon head bolts to ISO 4014 and DIN 931 in A2 (304) and A4 (316) stainless steel. A2 runs from M5 to M45 and A4 from M5 to M48, in lengths up to 500mm, and many A4 sizes come in both property class A4-70 and the stronger A4-80.
The plain, unthreaded shank under the head gives cleaner shear behaviour where it passes through the joint, which makes these the usual choice for steelwork, heavy timber and timber-to-metal joints. Use a fully threaded hex set screw for blind holes or thin material.
Frequently asked questions
What is a DIN 931 hex head bolt?
A DIN 931 hex head bolt has a hexagonal head and a shank that is only partly threaded, leaving a plain section directly under the head. ISO 4014 is the corresponding ISO standard; check the specified dimensions when replacing a DIN bolt. It is the standard hex bolt for joints where a smooth shank should sit in the shear plane. Simfix stocks them in A2 (304) and A4 (316) from M5 to M48.
DIN 931 vs DIN 933: what's the difference?
DIN 931 (ISO 4014) bolts have a plain, unthreaded shank under the head and threads only on the lower section. DIN 933 (ISO 4017) bolts, also called hex set screws, are threaded along the full shank. Use DIN 931 where the plain shank needs to sit in the shear plane, typically steelwork and timber-to-metal joints; use DIN 933 for blind holes or thin material.
What does A2-70 mean on a bolt?
A2 is the stainless steel grade (equivalent to 304); 70 is the property class, showing a minimum tensile strength of 700 MPa. So A2-70 means a 304 grade stainless bolt rated to at least 700 MPa before failure. Class 80, as in A4-80, means at least 800 MPa. Many Simfix A4 hex head bolts come in both A4-70 and A4-80.
What sizes of hex head bolt does Simfix stock?
A2 (304) from M5 to M45 and A4 (316) from M5 to M48, in lengths up to 500mm. Not every length is listed at every size and grade; check each product for current availability.
Sizes, grades and pack quantities vary by product type. Check the individual product listing for the exact specification and current availability.