drill and tap

Hi, ready to mount my floor shifter(Mustang C-4). Going to use 1/4 x20 x3/4. What size drill bit should I use before the tap?

Thanks
Tony

 

see: http://www3.telus.net/public/aschoepp/tapdrill.html

(3/16" should be fine - depending on the application and materials you're tapping)

 

what are you tapping??

...

 

Going to mout the shifter to the trans tunnel. The Grabber had the auto shifter on the tree. Someware along the way it was move to the floor. But it kepts comming lose. So I want to drill and tap the trans tunnel and mount with some good screws.

LATER
TONY

 

Number 7 from the tap chart we have here.

 

Won't do much good to tap the sheet metal tunnel. The metal isn't really thick enough to put threads in. I am guessing it is held in with sheet metal screws right now. Just use bolts with nuts and a little locktite. You will need to ask a friend to help.

 

slap some rivit nuts on it
Robert

 

Thanks for info . I had to used some sheet metal screw for now. I like the idea to use rivit nuts. Where do I get some?

 

if you have a drill and tap kit, there should be a piece of paper that tells you what drill bit to use..

 

As mentioned above, a 1/4-20 screw needs at least 1/8" of metal thickness to really grab on to it. Sheet metal screws should work better on your application than the 1/4-20 screws.