Size picker · Hex socket drive · DIN 7991
Countersunk socket screw sizes.
A 90° countersunk head with an internal hex drive, for a fastening that finishes flush with the surface. Pick a diameter and length for the head diameter, head height and key size.
1 Pick a diameter
2 Pick a length
Choose a diameter first.
Your browser could not draw the 3D view. The dimensions beside it are unaffected.
Drawn to proportion from the standard dimensions. Illustration, not a photograph of the item.
Selected
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| Sym | Dimension | Value |
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Job stopped? Ring 01327 877577 and we'll check the stock while you're on.
Read the full DIN 7991 size chart
| Size | 4 | 5 | 6 | 8 | 10 | 12 | 14 | 15 | 16 | 18 | 20 | 22 | 25 | 30 | 32 | 35 | 40 | 45 | 50 | 55 | 60 | 65 | 70 | 75 | 80 | 85 | 90 | 100 | 110 | 120 | 130 | 140 | 150 | 160 | 170 | 180 | 200 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| M3 | |||||||||||||||||||||||||||||||||||||
| M4 | |||||||||||||||||||||||||||||||||||||
| M5 | |||||||||||||||||||||||||||||||||||||
| M6 | |||||||||||||||||||||||||||||||||||||
| M8 | |||||||||||||||||||||||||||||||||||||
| M10 | |||||||||||||||||||||||||||||||||||||
| M12 | |||||||||||||||||||||||||||||||||||||
| M14 | |||||||||||||||||||||||||||||||||||||
| M16 | |||||||||||||||||||||||||||||||||||||
| M20 | |||||||||||||||||||||||||||||||||||||
| M24 |
The range shown is what fastener wholesalers commonly list — not a claim about what the standard mandates, and not a stock list. In-between lengths (85, 95, 170…), lengths past 300mm and odd diameters like M7 are made too, and availability varies by finish and grade — ask us for anything you can't see.
M22 and M24 have 60° heads, not 90°. Everything up to M20 in DIN 7991 is a 90° head; at M22 and above the standard switches to 60°. A 60° screw will not seat properly in a 90° countersink — check the countersink before ordering the big sizes.
DIN 7991 or ISO 10642?
They are the same family and the same 90° head, but the published tables print different figures — head height especially (an M12 is 6.5mm in DIN, 7.44mm in ISO, because ISO tabulates the theoretical sharp corner). The figures on this page are the DIN 7991 set, which is what UK trade stock is made and sold to. Do not mix the two tables when you are checking a countersink depth.
Where the head can stand proud, a button head or a cap screw gives more clamping strength for the same thread.
Not sure which you need?
Bring the old one in — Baird Close, Daventry.
More size charts
Every size, drawn to scale.
Hex setscrews
DIN 933 · full thread
Hex bolts
DIN 931 · part thread
Socket cap screws
DIN 912
Low head cap screws
DIN 7984
Button head screws
ISO 7380-1
Flanged button heads
ISO 7380-2
Grub screws
DIN 913–916 · five points
Nuts
DIN 934 · nyloc · thin · Stover · flange
Washers
ISO 7089 · BS 4320 · penny
Not sure what the markings on the head mean? Bolt grades explained covers 8.8, 10.9, 12.9, stainless A2 and A4, and the imperial SAE grades.
All of it comes off the shelf at Baird Close — see the full fasteners & fixings range, or every size guide.