For engineer: what's the meaning of "TACK" in weldment call-out ?

Question

THANKS.

Answer 1

tack welding is a small application of weld metal. it can be used in two ways. One is in places where the loads are small so not much weld is required. But it is usually utilized to hold two pieces relative to each other. it still allows moving the pieces by striking with a hammer for minor adjustments. Once the pieces are in place to the satisfaction of the welder and quality control inspector, the real weld is applied. Many time once the permanent weld is started, the tack weld is ground off.

Answer 2

After items to be welded together have been positioned as required, generally by clamping them, tack welds are used as a temporary means to hold the components in the proper location, alignment, and distance apart, until final welding can be completed.
In short-production-run manual welding operations, tack welding can be used to set up the workpieces without using fixtures. Typically, tack welds are short welds. In any construction, several tack welds are made at some distance from each other to hold edges together.
An advantage of this provisional assembly procedure is that if the alignment for final welding is found to be incorrect, the parts can be disassembled easily, realigned, and tack welded again.
In general, tack welding is performed by the same process that is used for the final weld. If the final welding is performed while the elements are still clamped in a fixture, tack welding must keep the elements in place and resist considerable stresses, not sufficiently contrasted by clamping devices, that tend to separate the components.
The temporary nature of tack welds may give the false impression that the quality of these auxiliary joining aids is not as important as that of final weld and that this operation doesn't have to be properly programmed, performed, and inspected. This is not true.
To ensure quality, most codes require that tack welding be performed only according to qualified welding procedures by welders fully certified in the process used for the final weld.

Answer 3

Tack Welding: A method of accomplishing temporary or working welds for positioning parts and/or solder on jewelry. These temporary welds become permanent joints through soldering or welding.