Which would make a stronger joint on square tubing

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Making a square frame would you be better off to cut a 45 on each end and weld all around or would you be better off to cut a 90 in the tubing leaving the backside uncut and bending to the square and welding 3 sides? Attached Images
Reply:Bending the tube puts a great deal of strain in that uncut edge.  It's likely to split at the outside of the corner.  The chances of it splitting will depend on the wall thickness of the tube.  You may not see cracks in the material right away.  If you heat it cherry red before you bend it, it'll do much better.    Likely faster to simply mitre cut the pieces and weld all four sides.  The outside edge of the corner will likely be straighter if welded.Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:Full cut and weld will be quicker, easier, more accurate and at least as strong. Bending will difficult to do accurately and will need heat to be successful. Cheers Andrew
Reply:Heat & bend it and you get a radius on your outside corner, 45 it, flap disc your welds & you get a nicer looking corner, on thinwall strength is about equal either way.
Reply:What is the frame for?
Reply:Originally Posted by thejonn2524What is the frame for?
Reply:Miter to what you like and add gussets over the joints and weld. Just cut a triangle out of plate, lay over the joint and weld. Provided it will not interfere with the entire project.
Reply:Originally Posted by BD1Miter to what you like and add gussets over the joints and weld. Just cut a triangle out of plate, lay over the joint and weld. Provided it will not interfere with the entire project.
Reply:Originally Posted by j_sephIt will have plate for the bed. Why I thought about cutting the 90 and bending was to give it a smoother edge on outside.thanks all
Reply:I'd miter, and not bend.  If you cut, then bend, you'll be filling more gap.  You can grind / polish that outside corner weld to make it look the way you want.  Or, you can do straight cuts, and put caps on the ends.-Aaron-Edit.....  Not sure which would be stronger.  I'd think they'd be similar in strength.Jet 17.5" Drill Press1942 South Bend 16x84 Lathe1980s Miller 320A / BP --- 2013 Power Mig 2562012 Jet 7x12 Horizontal BandsawVictor O/A Setup
Reply:I believe whichever joint has the most amount of weld is the strongest.  So coping it would give you the most linear inches of weld.   It's much more difficult to approach, but that's why it's done.TA Arcmaster 300CM3XMT 304S22P12 suitcase feederX-Treme 12VSOptima pulserTA161SMaxstar 150STLHypertherm PM45OP setupStihl 020AVP, 039, 066 Magnum
Reply:Why not a 90° butt joint?
Reply:bending it will save a lot of fitup..no clamping needed..bend, tack the 2 inside corners and ready to weld
Reply:45 is a lot faster and more accurate fit up. You can cut it on a saw instead of hand cuting the Vee out and bending. After you have cut the miter and tacked up the joint you can use a grinder and remove some of hte outside edge before welding, then weld, the use a flapdisk and radius the outside corner.