Quote:
Originally Posted by rrobson
Just as a side note, I wouldn't ever be worried about 1.6 microns on anything to do with cars 
I think you meant 1.6 thousandths of an inch in which case grab your pair of feeler gauges and look at the thickness of the thinnest one. Isn't going to make a dot of difference in a hole of any size when running a tap down. You'll loose more than that drilling free hand.
Maybe you were thinking of m5 which has a 4.2mm tapping drill?
7/32 would be a bit big looking at the old Zeus book, just over 5.5mm. If you had to use an imperial drill you'll get away with a 13/64, which is about 5.15mm.
I have used 3/16 drills in the past, they are 4.75mm and it is very difficult to get an m6 tap started but will get you buy on soft materials. |
There’s a word I haven’t heard of in 40 years, can’t even think what happened to my Zeus book