Slot weld
Applied to joint
Overlapping plates — plug weld through hole
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Description
A weld made in an elongated hole (slot) in one member to join it to the surface of an overlapping member. Similar to a plug weld but the hole is elongated rather than circular. Orientation, width, length, and spacing are specified.
In plain English
Same principle as a plug weld, but the hole is a slot (elongated oval or rectangle) instead of a circle. Gives more weld area and a stronger connection than individual plug welds. The slot orientation matters and should be shown on the drawing. Width and length of the slot are specified, along with pitch if there are multiple slots. Used when you need more shear strength than a single plug weld provides.
Symbol position
Rectangle symbol on the reference line (same as plug weld). Dimensions distinguish it from plug weld.
Size notation
Width 'c' to the left. Length to the right. Pitch shown if multiple slots. Orientation shown on the drawing.
Common uses
- Overlapping plate connections requiring high shear strength
- Deck plate to beam connections in shipbuilding
- Stiffener attachments where edge access is limited
- Composite steel-concrete deck connections
