Here's the math: http://web.itu.edu.tr/~halit/Makel/Ch_9_slides_m.pdf http://web.itu.edu.tr/~halit/Makel/Ch_9_slides_m.pdf The PDF is an excerpt from Shingley'

Here's the math: http://web.itu.edu.tr/~halit/Makel/Ch_9_slides_m.pdf http://web.itu.edu.tr/~halit/Makel/Ch_9_slides_m.pdf The PDF is an excerpt from Shingley's mechanical engineering design textbook. It's is considered to be one of the Mech E bibles. If you like buying random interesting books, buy it. Food for thought: Most welding applications that "normal" people would do would experience forces that range from 1lb to 2000lbs. (This a bad assumption, but whatever) If you actually do the math, it's even a small weld bead would have the strength of several hundred pounds force. Another general rule of thumb is that the base material will fail before the actual weld, if done properly. The easiest way to mitigate the risk, is to weld the entire seam, but you risking warping your part. The other thing is making sure you have full weld penetration when doing the weld. Penetration is affected by a multitude of parameters(amps, speed, technique), easy way to check is to look at the backside of the weld. Harder way is too cut a cross section at the weld. Or if you're going to ball hard. X-ray it.