How can I make a square hole 4 in. deep in wood or metal?

  • Advertise with us

« back to Power Tools, Hardware and Accessories forum

Forum topic by blackthumb posted 04-24-2009 04:52 PM 9595 views 0 times favorited 11 replies Add to Favorites Watch
View blackthumb's profile


32 posts in 3691 days

04-24-2009 04:52 PM

I need to make a 1/4 inch hole about 4 in. deep in a wood handle I guess there are mortising bits, do I have to buy one of those or is there some other way? I also need to make the same size hole in metal, do I have to file it out by hand? Thanks.i

11 replies so far

View poopiekat's profile


4353 posts in 3727 days

#1 posted 04-24-2009 05:11 PM

For metal there are special toolholders for metalworking lathes which are round on the outside, square on the inside. I’d bore a round hole and press-fit one of these into it. Available at McMaster-Carr, they have a great catalog and website. I’ll help you find it if you are interested. I think Enco has the same thing in their catalog as well. Otherwise, maybe some metalworking hobbyist might have a broacher, I can’t think of any other way to get a square hole in thick metal like that.

-- Einstein: "The intuitive mind is a sacred gift, and the rational mind is a faithful servant. We have created a society that honors the servant and has forgotten the gift." I'm Poopiekat!!

View PurpLev's profile


8535 posts in 3641 days

#2 posted 04-24-2009 05:20 PM

you can also drill it with a 1/4” drill bit, and use a 1/4” (or smaller) chisel to square it off since most of the material will already have been removed in the drilling operation – use some scrap piece above the hole, to help you align the chisel straight down, and on the square line. take small bites.

for metal, filing I think would be the way to go – there are small rectangular/trignale files that can reach in and are thin

-- ㊍ When in doubt - There is no doubt - Go the safer route.

View polygon's profile


5 posts in 2521 days

#3 posted 06-24-2011 06:13 PM

For future reference, the metalworking tool here is called a broach, and the usual tool is a broaching machine, which will run the broach completely through the part and cut the square hole. However, if you have a blind hole then you may be able to use a rotary or wobble broach. The rotary broach is a polygon punch that looks like it wobbles from corner to corner. That said, these are not ideal tools for woodworking, the design is typically too aggressive for wood grain.

-- Peter, Fort Fyers - FL,

View Bertha's profile


13525 posts in 2686 days

#4 posted 06-24-2011 06:20 PM

For wood, how about after drilling (preferably on the lathe), complete the ends with a small chisel (the visible portions), then hit the innards with a small long corner chisel? Or how about a very small person with an even smaller chisel to climb within? Good luck! :)

-- My dad and I built a 65 chev pick up.I killed trannys in that thing for some reason-Hog

View ChrisForthofer's profile


150 posts in 3060 days

#5 posted 06-24-2011 07:12 PM

Wood broach’s

Just ran across them the other day hope it helps

-- -Director of slipshod craftsmanship and attention deficit woodworking

View philip marcou's profile

philip marcou

264 posts in 2590 days

#6 posted 06-25-2011 07:48 AM

For the metal side of your question there is A BROACHING tool just as Polygon has described and Very expensive….
Chris’s recommendation of that Beal wood broach looks like the ideal tool but if doing just a few holes you may not like the cost-so I suggest a 1/4” square coarse file would work if you drilled first then hammered the file through. File may not be the same again but a cheaper option….

View polygon's profile


5 posts in 2521 days

#7 posted 06-26-2011 11:30 PM

Nice option Philip. It usually really does come down to how many pieces you want to make to justify any cost. Also, 4” is pretty deep for rotary broaching, so that may be the best option anyway.

-- Peter, Fort Fyers - FL,

View Bertha's profile


13525 posts in 2686 days

#8 posted 06-26-2011 11:34 PM

Once Philip chimes in on these matters, I tend to tune out other commentary.
The broaching tool is uber-expensive

A mill file, however destroyed, not so bad.

-- My dad and I built a 65 chev pick up.I killed trannys in that thing for some reason-Hog

View mousejockey's profile


67 posts in 2935 days

#9 posted 06-27-2011 03:11 AM

For the wood you can make two pieces “L” shaped with the leg being 1/4 in. and glue them together then shape it as needed. I don’t know the purpose but it can be done pretty clean if you’re careful.

View philip marcou's profile

philip marcou

264 posts in 2590 days

#10 posted 06-27-2011 07:06 AM

Cr1: you failed to observe that the hole is 4 inches deep….
Mouse Jockey has come up with the best option for wood, which I completely forgot to mention! Just use a 1/4” straight router bit and cut a groove 1/8” deep along the centre line of two pieces each being half the thickness of the square billet required for the handle, then glue them together.That’s the way those long standard lamps etc are made.

View Chuck's profile


18 posts in 2519 days

#11 posted 06-28-2011 02:48 AM

Just a suggestion: A triangular bit (think of a triangle file) will drill a square hole. It’s an old (like 18th century) woodworking trick. You have to drill a round hole first. Try it out on some 3/4 wood. A hole with any number of sides can be drilled by using a bit with one less side (surface) than the desired hole. A square bit will drill a pentagonal hole for instance.

-- "And then there was a pile of wood for which I forgot him, and let his little fear, Carry him off the way I might have gone..." -- from The Wood-Pile by Robert Frost

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics