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I am thinking about making table legs out of 2 inch wide flat by 1/8 inch think. how much weight would this hold? or should I go to a thicker size like a 1/4 inch thick. thank you for any help new welder here. I know the process and how it works, just need some help with what metal to use for this project.
Reply:There's a lot that goes into it besides the thickness and material choice. 2"x1/8" will have more strength than you could reasonably throw at it to break... but it's going to either unacceptably deflect or permanently bend before it outright breaks. Read up on design topics like Statics or Strength of Materials using websites like engineer edge. Cheifly, you should read up on how cross sectional profile (also known as Area Moment of Inertia) effects deflection, how to calculate maximum moments, and also calculating buckling stability. But to give you a little direction, look into angle-iron or round tube/pipe. When looking at "small" projects, those profiles are about as cheap as you'll get for still retaining good bending strength. Although if you expect torsional loads, skip the angle and go with tube. I don't think flat of any type would make a good choice for any sort of compression loading like a table leg would see unless you're going to weld a few to each other lengthwise to make a more complex cross-sectional shape... in which case you should have just bought a different shape anyways.
Reply:A table leg is similar to a column. Your biggest concern isn't compression, it's buckling, or deflection in bending. That is usually based on thickness of the thinnest dimension and it's overall unbraced length. Think of a 2x4. if only 1' long it will take a tremendous amount of weight on end before it crushes. Chances are it won't bend or buckle. Now that a 16' 2x4 and load the end of it. It won't take much weight at all before the thing starts to bend and then breaks. Brace the center of that 2x4 and you have effectively cut the length to 8' and it will take more load than the 16' one will by far, yet still not take what the 1' length will before it bends.Same goes with your 2" x 1/8" flat. In the 2" direction it will be very tough to bend, even if it was only made of 20 ga rather than 1/8". In the 1/8" direction, I can probably bend a 12" bar with relative ease by hand.Dimensional shapes self brace themselves. Square tube, round tube, angle iron etc, because they have sides that are braced to themselves, they are much more resistant to bending. Round tube will take a huge amount of compressive weight as long as the diameter is wide enough. 2" thin wall pipe 30" long is very hard to bend. It gets even stronger if you brace the legs with a shelf, effectively reducing the unbraced overall length..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Here is a way to think about the strength of any thing. If you take piece of paper and try to stand it up has a flat piece it will simply fall to the ground. Now fold the paper into a 90* corner then stand it up it could stand for a period of time on it's own. Now take the same paper and fold or roll into a tube and stand it up on end. it will support a little weight on top of it before it collapses. Now this is the same piece of paper the drop to the ground. The shape of anything used to support a weight is the design of said object. Remember that your science teacher try to teach you that in school?Klutch 220si mig , stick, and dc tigHobart 140 AHP ALPHA 200X 2016Lotos LTP5000DSmith O/P
Reply:Turn that piece of paper into corrugated card board and you'll be amazed at how much weight it will hold up with that same "piece of paper". They make pallets out of cardboard..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan |
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发表于 2021-8-31 22:10:49