What is the correct design for a runout tab?
The fact that the purpose of the runout tab is produce a sample of weld that is identical to the production weld dictates the design of the tab. Ideally, the plate of the tab is from the same heat and thickness as the workpiece. It should be of a size that will produce neither unusual heating or unusual cooling. It should be large enough to readily supply the samples necessary for the qualification tests selected. Experience indicates that tabs from 6x6xt to 12x12xt inches finished size have been satisfactory. Sample material can be obtained from the plate itself when there are manways or nozzles to be cut, but this source of samples may not always be available. When a bill-of-materials order is made for a large project construction, with special sizes of plate being rolled, there may not always be off-cuts from the plates for the sample material. It is a good idea to obtain the sample material with the purchase of the plate in order to assure the availability of matching sample materi
