F size drills

O

oldwolf

Joined
Dec 29, 2002
Messages
617
I don't know what's going on as I've purchased F size drills before, but ENCO and I have been going round and round trying to get some drills from them that will drill a slightly bigger hole than a quarter inch.
First ones I bought would not let a quarter inch rod go in without a hammer:grumpy: the return lady said it was probably because they came from China. I said OK give me some American made F drills. Returned the china ones and got the GOOD ones. Same darn problem. Won't fit. My micrometer says they are the same as my 1/4" drills. Lady in the return dept. said the china ones I returned were checked and were OK ???
What size do I need to order besides F? I'm getting old and brain is not as good as before, so is it me?

Ken
 
Not all quarter inch rods/pins are actually a quarter inch in diameter.

YOu could take a little off of your pins by sanding a bit. Many do. Personally F bits have worked well for me for quarter inch pinstock
 
I'd suggest looking at a sterret chart, then measuring your pins and but and seeing what is causing your issue
 
An F bit is .256". Thats what I use for my lanyard tube. Measure your pin stock and see what it is. If its 1/4" it should be .250" and a F bit will work great. If not your next size up is .26?which may be too big. Just sand your pins down a little if you have to.
 
Also.....Check that the pin stock/thong tubing is round...
 
Pin Stock varies and I will generally cut the stock long and spin it in the drill press and use 120 grit shop roll to rough up the pin and take it down some then test fit and cut to length save the grief of hammering and cussing undersize holes.
 
I use F bits from lakeshore carbide and even with that the tubes still will not fit most of the time. It's usually not a problem with G10, but micarta, terotuff, and especially wood all expand a little after they are drilled. For wood I usually end up using the next size up bit.
 
Well, looks like my mic is a little off. reads .250 when it's really .256. Found an old drill that was marked .256. Drilled a bunch of holes in wood and steel and I've got some clearance for my tubes. Not quite sure what made me think the drills were off.
Thanks for the response Guys.

Ken
 
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According to my chart, F drill is the next size up from 1/4". I use a F drill and it works fine. If the F drill is too small, the next size is the G drill, then the next larger size is the 17/64 drill. the E drill is the same size as the 1/4" drill. It could be you were sent E drills instead of F drills.
 
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