How do I drill square holes in a piece of stock?

Nelson

Nelson

Site Founder
Administrator
Joined
Sep 22, 2010
Messages
7,220
Using the drill press, lathe or millng machine, how do I drill square holes in stock?


Nelson
 
It depends on how much you want to spend. The easiest and cheapest is to drill the hole with a drill and then use a file to to square it out' The next step up is to drill the hole and broach out the square. Broaches can be made or purchased. Then come rotary broaches, EDMs and other expensive equipment. Blind holes are going to require the expensive stuff or very intricate hand crafting.

Randy
 
Depending on the nature of the product, there may be a way around it (so to speak). I have made crank handles by milling a slot, then welding a small plate in place to make up the 4th side. A little machining, or grinding....and you have a square hole suitable for a vise handle or some such. If you have a blind hole and have to rotary broach it, or hand work it, cut a relief groove at the bottom so you have a place for chips to go. A normal broach won't work in a blind hole. Too long.
 
You can buy square holes in the form of a shaft with a square hole in the center from most good supply houses. I keep a few around for making tool holders up and you usually you put a set screw in it so that holds it in place. ;) You can also lo-temp silver braze the sleeve in.:biggrin:
Also have a bunch of silver solder left over from my working days & sure am glad at the price today. You can achieve 60000 psi strength with the silver braze which is as good as 6011 welding rod;)
 
Look up Watts drill made near Pittsburgh, PA. They cost alot, but work good. Mill out 2 half pieces then weld together is a cheaper way if that will work for you.
Paul
 
+1 on the Watts Drill Chuck. They work great! I have two different sizes of them. I have done 3/8' and 1/2' square holes. With different drills and guide plates you can also do hexagon holes.
 
I remember my first boring bar a long time ago. I needed a 1/4 square I know I could have filed it, but I tend to do
things on the dark side. I drilled a hole where I wanted it slightly just under a 1/4 then I heated it cherry red and
with a 1/4 HSS blank I pressed it right through then drilled 1/8 for a set screw heated it up again & threw it in a
bucket of drain oil. I still use this mainly for internal threading. Funny that this subject came up because the other
day on modern marvels the story on Cromwell Tools it showed red hot blanks and a male form pressed it in the red hot
blank, theres ya socket, only probably 100 a minute then drops in a bucket then gets the hard treatment then to the
chrome shop. Suppose you could heat with propane and use a vise instead of a shop press.
 
I asked this question in another post and never got an answer. I thought somewhere I'd seen them in perusing catalogs but can't find again. Can you be more specific on a source?

bvd1940 said:
You can buy square holes in the form of a shaft with a square hole in the center from most good supply houses. I keep a few around for making tool holders up and you usually you put a set screw in it so that holds it in place. ;) You can also lo-temp silver braze the sleeve in.:biggrin:
Also have a bunch of silver solder left over from my working days & sure am glad at the price today. You can achieve 60000 psi strength with the silver braze which is as good as 6011 welding rod;)
Click to expand...
 
You must log in or register to reply here.
Back
Top