Primer material thickness strength?

[Whiskeymike]

I recognize that a lot of this comes from experience and failures to be able to recognize the right size, but can anyone point me to a primer on the relative strength of steel tube by size and thickness so I can determine what I should choose for simple projects like a saw stand, carts, tables, etc..?

Or is there a rule of thumb for the differences between square and rectangle tube and angle as well as thickness comparison?

Thanks

 

[zkling]

These should get you started. You want to stay below the yield strength of the material. Get a copy of Shigley's. Machinery's hand book has the formulas, but doesn't really go much in the way of teaching how to use them, which is what Shigley's does.

Bending
http://www.engineersedge.com/strength_of_materials.htm

Columns
http://www.efunda.com/formulae/solid_mechanics/columns/intro.cfm

One thing to keep in mind, it is usually more effective to increase the diameter or l*w than to increase a wall thickness.

 

[Whiskeymike]

Thanks for those recommendations. I'll take a look but I think they are beyond where I am at the moment.

Maybe to get started on my initial issue, I can ask a different way. I just purchased a welder and I'm in the learning process. I want to build some carts and stands for things. What gauge do you commonly use for carts, stands for saws, etc.. This wouldn't be for a 4x8 1/2 welding table. But a welding cart, stand for a 4x6 horizontal band saw, that type of thing. I'd like to purchase a few sticks and don't want to purchase the wrong stuff right off the bat. I'd rather error on the safe side.

 

[tw0st3p]

What type of material are you using? Angle, pipe? For most of my projects I use square or rectangle tube with a .125 wall thickness and haven't had any weakness issues.

What type of welder did you get?

ETA: I recently built this welding table and it is made entire of .125 thick material, aside from the top, and it is extremely rigid.

 

[Fcvapor05]

Thanks for those recommendations. I'll take a look but I think they are beyond where I am at the moment.

Maybe to get started on my initial issue, I can ask a different way. I just purchased a welder and I'm in the learning process. I want to build some carts and stands for things. What gauge do you commonly use for carts, stands for saws, etc.. This wouldn't be for a 4x8 1/2 welding table. But a welding cart, stand for a 4x6 horizontal band saw, that type of thing. I'd like to purchase a few sticks and don't want to purchase the wrong stuff right off the bat. I'd rather error on the safe side.

Calculating loads on things like stands is more complicated than it seems- if you were to just figure out how heavy your band saw is, then build the stand 'strong enough' to hold it up, you'd be using very thin tubes with very small diameters. Then you'd potentially have issues if you ever subjected the stand to side loads (which you will).

If you want to build tables and stands and whatnot, I'd suggest several sticks each of .125" wall 1x2", 1x1", and 2x2" square mild steel tubing, and a few sticks of .125" angle iron in 1.5x1.5" or 2x2", exactly like the table shown above. It will be way more than the 'minimum' strength required, which is what you want. Simple, overbuilt structures are where it's at for shop equipment. Square tubing is also much simpler to miter complicated joints than round tubing is. Don't overthink it. Anything .125" wall is going to be relatively easy to weld and cut without crazy equipment.

 

[Whiskeymike]

What type of material are you using? Angle, pipe? For most of my projects I use square or rectangle tube with a .125 wall thickness and haven't had any weakness issues.

What type of welder did you get?

ETA: I recently built this welding table and it is made entire of .125 thick material, aside from the top, and it is extremely rigid.

I plan to use square or rectangle tube. I like the look of rectangle, so was leaning that direction. Maybe some angle for having edges.

I got a Hobart 190 with 75-25 mix. I'm currently using .030 wire.

That's a good looking table.

 

[Whiskeymike]

Calculating loads on things like stands is more complicated than it seems- if you were to just figure out how heavy your band saw is, then build the stand 'strong enough' to hold it up, you'd be using very thin tubes with very small diameters. Then you'd potentially have issues if you ever subjected the stand to side loads (which you will).

If you want to build tables and stands and whatnot, I'd suggest several sticks each of .125" wall 1x2", 1x1", and 2x2" square mild steel tubing, and a few sticks of .125" angle iron in 1.5x1.5" or 2x2", exactly like the table shown above. It will be way more than the 'minimum' strength required, which is what you want. Simple, overbuilt structures are where it's at for shop equipment. Square tubing is also much simpler to miter complicated joints than round tubing is. Don't overthink it. Anything .125" wall is going to be relatively easy to weld and cut without crazy equipment.

Yep, I'm great with overbuilt. So it looks like .125 is 11 gauge, so if I stick to that, it should be simple to use them together. Then just try and experiment and learn the use.

This is tough working with a new material. After years of working with wood, you have a pretty good sense of what a 2x4 will support. But that doesn't translate to steel at all. . Also makes it fun.

Thanks guys, much appreciated.

 

[zkling]

1", 0.095" wall is a good compromise between mig weld-ability and structural integrity.

 

[Whiskeymike]

1", 0.095" wall is a good compromise between mig weld-ability and structural integrity.

The hobart 190 is rated to 5/16", should I have any difficulty with .125?

 

[zkling]

The hobart 190 is rated to 5/16", should I have any difficulty with .125?

No, it is just a bit thicker than really needed. Most of those types of carts you are talking about are in the 16ga (~0.065") range, which can be a bit tedious to mig at times.

 

[plow]

Here.

http://weldingweb.com/forumdisplay.php?10-Welding-Projects-amp-Pictures


Start with a welder cart or a welding table. Nice 1st welder BTW. Have Fun!

 

[plow]

Inspiration.

http://weldingweb.com/showthread.php?429221-Grandfathers-clock-project

 

[cyato]

For most shop-duty carts, I would recommend 0.080" wall thickness material. The 0.090" or 0.095" material that zkling suggested is nice as well. I've made numerous stands, carts, tables and frames over the years with 1x1, 1x2, and 2x4 mild steel tubing and find it to be my favorite combination of strength to workability. The 0.120"/0.125" material is considerably more work to cut and is heavy.