Angle iron crossmember in an angle iron frame

I have a frame that was constructed with angle, 2"x2"x.25". The frame is 4'x3'. I want to add two 3' lateral supports made of 2.5"x2.5". Should these two supports bet notched, so they are flush with the existing frame, or should they go under the frame? I know there will be some material hanging over no mater which method I use because of the extra half inch.

It's going to need to be able to hold a lot of weight, around 300-600 lbs per end. It's holding a 1200 lb surface plate plus whatever is on top of the plate. I'm more interested in what will be strong, not really cosmetically appealing because I won't see it.

I'm also having a hard time finding out how much weight a weld is supposed to be able to hold. The material is made of 304 stainless, and I will do some test welds on some scrap material to see how they hold up when compressed.

I guess while I'm on the subject. Should I consider constructing this crossmember out of steel instead of stainless? Could find a large C chanel piece that is 2"x3-4" and a quarter inch thick.

"Design of Weldments" will have tables for weld strengths (no calculations needed)
As well as various examples of bracing configurations, with resultant
strengths.

With full penetration, the weld should be stronger than the parent material (because the weld is thicker).

A welding engineer is a vocation of its own right, but if you want to get a sense of it, look at your design and figure out what the cross sectional area of the material is that would have to shear for it to fail. Then multiply that by the tensile strength. Intuitively 1200 lbs seems a very small load for 2 x 2 x 1/4" welded.....but only you know the design.

Mcgyver said:

With full penetration, the weld should be stronger than the parent material (because the weld is thicker).

A welding engineer is a vocation of its own right, but if you want to get a sense of it, look at your design and figure out what the cross sectional area of the material is that would have to shear for it to fail. Then multiply that by the tensile strength. Intuitively 1200 lbs seems a very small load for 2 x 2 x 1/4" welded.....but only you know the design.

Click to expand...

No need to do ANY of this...there are charts.

Use them, apply them, follow them.

The Design of Weldments" book doug noted is available new and cheap from the Lincoln Arc Welding Foundation: Books

I'd also recommend the Welding Procedures Handbook, same publishers.

Between those two you'll have all the information needed.