In laying out sheet metal pieces to be joined by a grooved seam, allowance must be made for the amount of material that is to be added for one lock for 24 ga or lighter, this is ___ times the lock width.

In laying out sheet metal pieces to be joined by a grooved seam, allowance must be made for the amount of material that is to be added for one lock for 24 ga or lighter, this is ___ times the lock width.