Getting a good square line on sq. and rect. tubing

Date 11-26-2006 22:22

Many times you will need to draw a square line on sq. & rect. tubing. As the wall thickness increases on these, so does the radius on their edges, most squares will not extend far enough over the side to pick up the flat part of the other edge. A couple of methods that I have to found to deal with this are as follows: take a piece of 10GA. or so sheetmetal and shear/or cut it into a rectangular shape, at one end of this rectangle form up the edge to 90 degrees with the leg length being around 1 1/4" to 1 1/2". You can use this to lay the short formed leg against the edge of the tube and draw lines along the edge that is 90 degrees to the short formed edge to make your square lines on the face of the tube. Another method uses a modified version of carpenter's stair gage sets. These are the small brass set blocks that can be attached to carpenter's squares for laying out stairs. A modified version of these are much longer in their body length and can still be attached to one edge of the carpenter's square. They can then be laid against the edge of the tube steel and a line drawn across the tube along the other edge of the square. I'm sure there are many other methods, these are just a couple that I thought I'd throw out there. Regards, aevald

By CHGuilford (****)

Date 12-15-2006 22:45

I didn't really notice this until now.

Another way is to simply saw off a piece of angle iron, making sure you are getting a good square cut. Lay the inside of the angle over the outside of the tube and draw a line across the end. That will mark lines on 2 sides that are 90 degrees to the tube's length and will work for almost any size tube.

I still have a piece of 4 x 4 x 1/4 x 6" long aluminum angle in my tool box from a number of years ago that I used to layout structural HSS tubes.

By monsoon12 (**)

Date 12-25-2006 17:59

Where i work a major steel company went out of biz.They had an auction an the owner purchased a ton of squares.One of the squares was a combo an it was set up for laying out tube.Basically where the handle of the square was it had a piece of plate attached to it.Thrus all you have to do is butt the piece up to the side of the tube an extend the blade to the measurement you need an mark your line.They also purchased a lagerer square with a arm on it on the insde of the square.It sides the lenght of the one side of the square an stays put at the other.Thrus createing a right angle.Which in turn gives you a pitch for setting things on a pitch.Like if your putting clips on a beam at 1/2 x12 pitch.you just set the square for 1/2 inch the top of the square remains at 12 inches an you have your pitch.Butt it up to the clip an it will give you the pitch you need.
I dont know everything but what i do know im willing to share,

By roping welder Date 04-13-2007 04:13

SWANSON MAKES A SPEED SQUARE THAT IS WIDE ON ONE SIDE AND IS MAGNETIC. WORKS GREAT ON THE HEAVY WALL ROUNDCORNERED TUBING

By XPERTFAB (**)

Date 04-15-2007 05:20

Yup! But buy two! Use one at the normal size and cut the other down to a four inch leg on the opposite and adjacent sides of the hypotenuse (45 degree angle). This fits good in your pocket and is real handy on layout for the average size stuff.