Written by Heather McHale, Technical Support
Have you ever designed something, and attempted to weld it together, but didn’t have enough hands or clamps? Did you have pieces propped together, hoping breathing didn’t cause collapse? If the end product is going to be produced hundreds of times, now would be the time to design a fixture. But what if this is a small job, a prototype, or you don’t have the time or resources to design and built a fixture? Consider tabs & slots.
Tabs & slots, commonly referred to as self-fixturing, it is the practice of adding tabs of material along with adjacent holes, to hold or locate parts properly during welding (or any other type of fastening application). This practice can ensure that the product is assembled the same way every time. It can also minimize or eliminate the need for clamps, and expensive fixtures.
We’ll look at this table as an example. At first glance the easiest process would be to cut each tube with a chop saw, a piece of equipment that most anyone working with structural members owns. Although the cutting process is very simple, the assembly will take multiple steps to layout and create sub weldments. This will require a lot of clamps and measuring to align components.
Now let’s look at a modified design of the table. By adding tabs and slots to the structural members, this version of the table can be made with very few, if any clamps. The components can be assembled with little to no measuring required (we would still verify critical dimensions) and will snap together like a puzzle. With tabs and slots used on this table, assembly time will reduce the weldment will be the same repeatedly, without the time and expense invested in building a fixture.