# Tack Welding

https://kdisplay.com/capabilities/welding/tack-welding

K-Display in Chicago tack welds machine frames, door subassemblies, and brackets in carbon steel, stainless steel, and aluminum from your assembly drawings. A tack is a short weld that holds the parts in position until the full weld is made, and the assemblies leave tacked or fully welded.

## Overview
A tack melts a short length of both parts into one, in carbon steel, stainless steel, or aluminum, and leaves the rest of the joint open. The full weld then melts the tacks back into the seam, so a tack laid in the joint becomes part of it. MIG and TIG welding, the arc processes that melt wire or rod into the joint as they go, run one continuous bead the full length of the seam and leave it finished, which is the weld a tack only holds a place for. Resistance spot welding joins one sheet laid over another, point by point, with no filler.

## Materials
- Carbon steel
- Stainless steel
- Aluminum

## Applications
- Machine frames, with the corners tacked so the full weld starts from a square frame
- Door subassemblies, tacked together for the door maker to finish-weld and install
- Brackets, tacked square to a plate or frame so the bracket can be set and checked before it is finish-welded

## Process
- Hold the parts together: We hold the parts against each other so their edges meet along the joint.
- Tack the joint: We tack the ends of a joint before its middle, because tacking from one end to the other lets shrinkage close the gap at the far end.
- Reset what is out of line: We check the alignment with the tacks on and break loose any tack that holds a part out of position, then set the part again.
- Weld in full or ship tacked: We make the full weld along each joint of an assembly we finish, and ship an assembly for you to finish with only its tacks holding the joints.

## Design considerations
On some weldments the weight of the parts passes through the tacks when the assembly is lifted, and an improperly tacked assembly can rupture when hoisted. Send how the assembly is lifted and shipped, and that decides where we put the tacks. On thin sheet, a gap between mating edges leaves no metal under the arc to take the heat, and the full weld can burn through there. Draw the mating edges to meet, and we tack them where they touch.

## Related pages
- [MIG & TIG Welding](https://kdisplay.com/capabilities/welding/mig-tig-welding)
- [Resistance Spot Welding](https://kdisplay.com/capabilities/welding/resistance-spot-welding)
- [Custom Welded Frames & Weldments](https://kdisplay.com/products/frames-weldments/equipment-frames-weldments)
- [Custom Door Subassemblies](https://kdisplay.com/products/door-access-systems/door-subassemblies)
- [Custom Machine Bases & Skid Frames](https://kdisplay.com/products/frames-weldments/machine-bases-skid-frames)