How to MIG weld square tube with flat plate

Square tubing by using a welding process, always has been a matter of interest and importance to manufacturing and fabrication industries. Here is the demonstration on ‘How to join a sqaure tube with a flat plate, using the Metal Inert Gas (MIG) welding process?’ As MIG process is easy to operate as compared to other types of arc process and you can create many futuristic things by this square tube to plate weld joint for your school projects. So it is important to learn about the MIG square tubing basics.

In this case you are going to weld edges of square tube to a flat plate. On absorption of heat, thin edges may melt more quickly than sides of tube.  Keep the MIG gun at such an angle that will direct more heat to the flat plate rather than to edges of tube. Remember to weld tacks on all sides in order to prevent the assembly out of order. Listed below are the critical points that need to know about MIG welding in such kind of joints.

  • T-joint
  • Clamping
  • Tacking
  • Weld Run
1. T-joint Assembly

Assembly of square tube with flat plate gives T-joint. So you have to deal with the fillet weld. In other words edges of square tube are welded with the flat surface of plates. Align the square tube with plate according to the required dimensions. 
2. Clamping
Before tacking, clamping is an essential part to prevent any disorder in assembly. So fair clamping is required with the acceptable force. Commonly it is done by some sort of tool or manually by a welder. Clamp the assembly for tacking.
3.Tacking

Tacking is followed by clamping. Once you are successful to fix the assembly in shape, next step is to tack the joints at the middle. It is noticeable that tacking must be at opposite sides. Tacking on adjacent corners or sides may lead to warpage or any distortion.
4. Weld Run

It is usual practice to commence and pause welding at joint surface. Try to lay weld beads from the middle rather than corners. As corners offer weak linkage that turned into the possibility of cracking due to stress. Weld it around the corner to get a continuous weld run. If you don’t make it around the corner, it may result in a blow hole at the edge of square tube.

All Comments

  • Here is the demonstration for the MIG welding of square tube with plates. You can create many futuristic things by this square tube to plate weld … weldermig.blogspot.com

    Mig Welder March 25, 2015 2:41 pm
  • Ugly bead

    Patrick Waste April 20, 2015 12:36 am
  • Ugly bead

    Patrick Waste April 20, 2015 12:37 am
  • It's not always important to make clean welds. If the weld is good in strength and completely free from defects then it can be qualified according to the quality requirements.

    Mekaal April 26, 2015 11:14 am
  • Agreed

    Biill Featherman May 3, 2015 12:59 pm
  • Still, if this was a decorative piece such as a mounting plate for a staircase railing you'll want a pretty bead

    Unknown October 13, 2015 5:01 pm
  • I like the way you have described. It is really very important to make clean weld. Thank you it’s really appreciable.

    Rob Simpson March 10, 2016 12:02 pm
  • I'm trying to make a transition from AC arc welding to gas welding and I am having some problems with the process. . Any ideas on where to start?

    Ken May 25, 2016 6:31 pm
  • I'm trying to make a transition from AC arc welding to gas welding and I am having some problems with the process. . Any ideas on where to start?

    Ken May 25, 2016 6:32 pm
  • Well it's not that complicated as the gas welding process is quite similar to TIG arc welding. Holding the filler rod in one hand and feeding it into the joint by flaming it with the help of torch in the second hand.

    Adeel Rafique May 26, 2016 3:27 pm
  • For more information you can read two more articles in the same blog;
    Handouts for welding basics
    Use of Welding Angles to improve your weldment

    Adeel Rafique May 26, 2016 3:35 pm
  • Slag trapped in the weld is a defect I wouldn't call that a weld I've seen welds like that fail with no weight.

    Unknown September 20, 2016 12:48 am
  • Slag trapped in the weld is a defect I wouldn't call that a weld I've seen welds like that fail with no weight.

    Unknown September 20, 2016 12:49 am
  • Exactly! Apart from slag there are also some other solid materials which entrap during a welding process. All welding associates must be aware of all those weld solid inclusions as they are liable to fail massive structures.

    Adeel Rafique September 20, 2016 7:12 am
  • if you can't swim, don't teach swimming, if you are not a bird, don't try to fly, you are not a welder because your welds are bad,your advise on tack welding is out in left field.so just ask for help and be done with it.

    Anonymous October 8, 2016 5:53 am
  • Good job done. The article is not bad, but it may more informative.

    Coleman January 13, 2017 6:01 pm
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