Drilled Hole positioning query on threaded bolt
[COLOR=#333333]Hi All,[/COLOR];cool;
[COLOR=#333333]I've just joined and have a specific question, that I hope you can help with;[/COLOR]
[COLOR=#333333]I'm up-issuing a drawing at present, relating to a machined block with a machined bolt going through it.[/COLOR]
[COLOR=#333333]The bolt has an M12 Thread on it, but there is no indication of what pitch the threads are (I don't know much about that anyway). I don't have any thread gauges available, only a vernier caliper.[/COLOR]
[COLOR=#333333]On the existing 'assembly drawing', there is a note which states:- Screw bolt in to block face, hand tight only. Then back off 1/4 turn.[/COLOR]
[COLOR=#333333]Then drill a 1/8" hole on the center line (of the bolt), completely through the assembly.[/COLOR]
[COLOR=#333333]The threaded end protrudes through the other side of the block, and a cap nut is fitted to it, with the same instructions as above.[/COLOR]
[COLOR=#333333]The 2x 1/8" holes are then pinned with slotted roll pins.[/COLOR]
[COLOR=#333333]The crux of my query is;[/COLOR]
[COLOR=#333333]How can I determine the bolt length, and the positioning of the 2x holes on the bolt? (1 on the shank near the bolt head, and the other through the threaded end).[/COLOR]
[COLOR=#333333]I want to add reference dimensions for the benefit of the machinist who will manufacture these items.[/COLOR]
[COLOR=#333333]How do I work out what distance the head of the bolt is from the face of the block?, after turning it back a 1/4 turn, from being hand tight against the face of the block?[/COLOR]
[COLOR=#333333]I can only guess at this at present, but there should to be a way to work it out, should there not?[/COLOR]
[COLOR=#333333]I would appreciate any help, that any of you can provide.[/COLOR]
[COLOR=#333333]Thanks & regards,[/COLOR]