8mm tap question?

[richirich]

I am going to attempt to tap out a stripped 6mm head bolt to 8mm.
I have a brand new 8mm x 1.25 tap but am unsure what size drill bit i need to drill the case before i try tapping it.
Thanks for the info

 

[GearNut]

Drill bit size K or I depending on the thread pitch.
Drill and tap size chart - Wikipedia, the free encyclopedia

Look about 2/3 the way down on the chart. Metric sizes are all in purple.

 

[richirich]

thanks for the info

 

[richirich]

actually the chart was incomplete. it had the size for the 8mm 1.00 thread pitch but not the 1.25 pitch. Ill keep looking

 

[Al.Fisherman]

actually the chart was incomplete. it had the size for the 8mm 1.00 thread pitch but not the 1.25 pitch. Ill keep looking

Bolt Depot - Metric Tap and Drill Size Table

Found in 10 seconds....It's amazing at how to look these things up.

GOOGLE... "drill for 8 X 1.25 bolt" 6.9mm or 11/64th

 

[richirich]

Thanks Al , that was exactly what i needed. Sorry, though sometimes we overlook the obvious.

 

[GearNut]

actually the chart was incomplete. it had the size for the 8mm 1.00 thread pitch but not the 1.25 pitch. Ill keep looking

Look 4 lines above the listing for M8x1.0.
It's a moot point now though, Al.Fisherman got it for you too.