View Full Version : How To make a Square out of Angle Iron
02-24-2010, 03:36 AM
Hello all, I am of course new to this whole asking for help thing but I just can figure it out. I have looked on YouTube for an actual video and still have not found one that I could understand.
My problem (Grin OK ONE of my many problems) is that I I just can't figure out how to make a square with something as simple as 1/2 inch or even 3/4 inch angle iron.
Yes I DO get it about cutting the Iron at a 45 degree angle, but ever time I do this it still does not line up the way it should. Does ANYONE have a video or heck even images from start to finish on how this is done the proper way.
It's just sad to say that I have a hard time trying to figure out how to make a square out of Angle Iron.
BTW - It's the how to cut it that's the problem for me.
03-10-2010, 12:42 PM
Do you have a carpenter square and a triangle square? How are you cutting the angle - abrasive saw, cutoff wheel? The heat from the weld will pull the sides out of square if not clamped.
Of course you need to cut as exact as you can, then sometimes you have to grind to fit. Mark your 45 degree line, cut outside that line slightly if your saw is not aligned properly, then grind to the line. Check it with the triangle square. Adjust until you get very close to a good 90 degree fit up, using the large square.
Usually, I layout the pattern on my welding table with the square and soapstone. Then clamp each side with locking pliers, c-clamps, whatever. Tack in two places. Then do the opposite pair using the same pattern and technique. Put both halves together and check square with your carpenter square. Grind, hammer, stretch until you have a good fit up and square. Clamp and tack the opposite corners. Re-check the square and adjust if necessary.
At that point you should have a good square frame. Weld opposite corners with final welding, usually on the outside, not inside depending on how you are using the frame.
Good cuts and fitup are key. Clamping, tacking, checking, adjusting, and re-checking will result in a good square frame.
Other techniques are to measure to opposite corners, then compare to the other half. If it is square, they will measure the same.
Good luck, post more information about your saw/cutoff, etc. and post pictures.
03-10-2010, 01:09 PM
You are most likely not cutting your material at a true 45 degrees. If you are doing it with a abrasive cutoff saw, the numbers they give you are usually only somewhat close.
03-10-2010, 02:49 PM
http://www.amazon.com/Wolfcraft-3415405-Right-Angle-Clamp/dp/B000JCGYD6 a right angle clamp also works miracles for holding things square. I used to use them all the time to square about small tubling and angle iron and the likes.
Also a magnetic triangle clamp works well too.
here's the order
line them up dry to check fitup
if off tap with angle grinder to get it better. if it's small I just set it open as you want a root opening anyways
measure squareness using a frame square on the back end.
once it's in square clamp it to table or however you want to keep it square.
I usually go about 5 degrees past 90 so I set it at 95 degrees. Then I tack on the inside corner.
the heat shrinkage will bring it back into square.
hopefully it's just perfect or a little oversquare, I bend it by hand back to square checking with a framing square on outside corner.
Now I clamp it up again
tack outside corner
weld it up
check when I'm finished it should be dead nuts.
If you just clamp something up at 90 then do a full weld and unclamp it will distort usually to something other than 90 degrees. If I can get it tacked up at 90 and balance the heat input. It should stay at 90
03-10-2010, 08:52 PM
I have made alot of frames out of angle and I found notching the ends is much better for me and easier. For small angle I notch it right on my chopsaw. In my hand i'll turn the angle paralell with the saw blade and feed the stock into the blade and (cut in)the diameter of the angle. Then I'll turn the piece 45 degrees and set in the chopsaw and cut the rest out like this.
WARNING These stunts are performed either by professionals or under the supervision of professionals. I insist no one attempt, recreate, or re-enact any activities performed.
03-11-2010, 12:22 AM
Boykjo is dead on,notching is the best way to join these pieces. Take a look at his diagram; cut the horizontal notch to accomodate the perpendicular piece. But, there are times when you will have to miter the corner but this is a tougher weld, probably easiest with a mig, more gap, edges feather out... and alot tougher to fit. All the posters are giving you good advice, get a machinist square and make your cuts dead on. Use a larger carpenter square to measure your longer runs (compounding error and all) You can usually hammer things square if you've only tacked in a couple of places. Chop saws can be terrible at 45 degree cuts. Sometimes I use a sawsall with a metal cutting blade and another piece of steel clamped on top as a guide. Above all accuracy is the key and like most jobs the more time spent on prep the better the result.
I build build alot of mobile bases (angle) for my woodworking machinery and I do them all with the notch method.
Hope this helps
03-11-2010, 08:05 AM
I don't worry about accurate fit up, almost not at all. I leave some gap, clamp it to the dimension I want and weld it up. Very rarely cut a 45 on a chop saw, might cut to length but nip the corners with other method, on occasion cut notches with the saw.
03-11-2010, 08:49 AM
Are you trying to make a square as in a tool? or a 4 sided square? Or are you just not able to make a square corner?
Even if cut perfect it takes a few clamps to hold it exactly where you want it. Then when you weld on the inside of a corner it will pull it in, If you weld on the outside it will pull it out.
03-11-2010, 09:58 AM
Steel expands when heated and contracts as it cools. Welds as they cool pulling square corner out of square.
You can have joint of square so cooling weld will pull it into square.
Welding fixture can hold parts in position for welding and hold alignment as welds cools. Fixture can be large and heavy. Wedge in joint (flat screw driver) can resist contraction as tack weld cools.
Big hammer or hammer and punch can adjust cold joint alignment.
Heating spot at on end of weld joint will shrink as it cools adjusting alignment.
Order of weld placement can reduce problem to acceptable limits.
Dropped Carpenter Square is out of square. Adjust with hammer and center punch near inside corner or outside corner to make it square again.