What size tap and drill for m10x1.25 helicoil

[NeEmO6]

Just as title states, I have the m10x1.25 helicoil inserts just need to know size of drill and tap for it?

 

[ed1380]

M12x1.25 tap and 13/32 drill bit

 

[BogusSVO]

He is asking about a 10mm not a 12mm

for a 10mm or 3/8 heli-coil you need a 25/64 drill bit

You also need the custom tap for the heli-coil

 

[ed1380]

25/64= .3906
13/32= .4062

Required is 10.3mm which is .4055
http://www.thorintl.com/Drill-Sizes-HeliCoils-Metric.shtml

a m10 helicoil will need a larger tap than a 10mm. I always assumed it was a m12x1.25. I never checked the size

 

[turboglenn]

YEa heli-coils have their own taps that aren't to metric or SAE spec it's it's own thing.

Just a general piece of FYI, most metric threads (standard too but using as example) the hole is drilled about 1mm smaller than the thread spec size..for example, M6 x 1.0 is drilled 5.2mm, M8 x 1.25 is drilled about 7mm etc..etc.. this is for room to cut threads for the overall diameter with threads included, or to have meat to stick into the threads of the bolts

 

[ColtiXim]

M6 X 1mm is drilled 5mm
M8 x 1.25mm is drilled 6.75mm

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[turboglenn]

Yea i was just going off the top of my head after a night with no sleep , i always look it up on the chart in my tap set and then mic out what bit to use since most of mine are illegible any more