When using heat to join metals, there are two main types of joints- butt joints and lap joints. Each joint brazing has its own advantages, depending on the type of project you’ll be undertaking. Here we’ll take a look at the two and compare.
Butt Joints
This type of joint is most commonly used in piping- joining the ends together or adding fitting, flanges, valves, or other equipment. It is used when strength isn’t of critical importance or there may be a thickness constraint. Having perfectly squared corners is very important when measuring to fit. Failure to square can compromise the strength and integrity of the weld. The filler material can be pre-placed or fed in while joining.
Lap Joints
When joining two larger, flat pieces of metal or creating an overlapping seal, a lap-joint would be the way to go. Unlike with the previous option, a lap joint can be used to join metals that are two different thicknesses. This method allows for a longer flow of the filler material, resulting in a higher load bearing capacity- making it ideal for circumstance where strength is a priority.
When properly designed and brazed, your project shouldn’t fail at the brazed joint. The fault should instead be attributed to where the weaker of the metals begins to yield under load-bearing stress. If you think a specific area may face more severe service conditions, consider heat treating the joint, no matter which method of joint brazing you choose.