UNJF Thread

[artin51]

Hi guys,
I have an aerospace part that calls for a UNJF thread. Does anyone have any ideas as to where i could purchase a single point UNJF cutter? This will be done on a mill.

thx

[MoSHO93]

any tool catalog should have one such as j & l or msc. The only diff between a unjf and a standard unf is the root of the thread has a larger radius than standard. I used to work for a company that made aircraft parts we made alot of unjf threads.

[mc-motorsports]

What does the J stand for? Sorry, spent my years in the machine building industry, very little aerospace experience.

MC

[Delw]

the J thread has a very critical rad. on the root. ( I dont know what J stands for) I found that sandvik inserts work the best.

some oldschoool and good carbide grinders will cut mill cutters for J threads,

[artin51]

Hi guys,
Thanks for the input. An iscar sales rep told me that because the threads that i'm cutting are internal, i have to use a regular UN insert and modify the drill diameter only to give clearance for the radius on the UNJF bolt. So i checked an online thread calculator and for a 7/8-14 unjf thread i need a .810 hole, where as for a 7/8 unf thread the diameter required is .806.