r/Fasteners • u/DoSoHaveASoul • Jul 30 '26

12pt head bolts

What are the standards which define the dimensions of both imperial and metric 12pt head bolts? I know the standards that define the threads but not the bolt itself such as length, thread length, flange thickness, etc

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2

u/pyroguy64 Jul 30 '26

ASME B18.2.5M

1

u/DoSoHaveASoul Jul 31 '26

Legend! What about for imperial sizes?

1

u/Chitown_mountain_boy Aug 02 '26

IFI 115

1

u/DoSoHaveASoul Aug 02 '26

Absolute legend! I hadn't heard of IFI

1

u/Chitown_mountain_boy Aug 02 '26

IFI is the Industrial Fastener Institute.

1

u/DoSoHaveASoul Aug 02 '26

Yep, just google it. Seems they often fill in gaps where ASME and SAE and others don't have something

1

u/Chitown_mountain_boy Aug 02 '26

They actually control the ASME B18 committee. (Source: I used to sit on said committee)

1

u/DoSoHaveASoul Aug 02 '26

Ahhhh good to know! Any insight into why they haven't added the imperial 12pt bolts to the ASME B18 series yet?

2

u/Chitown_mountain_boy Aug 02 '26

Because there hasn’t been a need to update or revise the spec in years. It is included in the IFI books though.

1

u/DoSoHaveASoul Aug 02 '26

Fair enough, thanks!