A method for automatically attaching a bolt for a mortise lock to its draw bar includes the steps of boring a hole longitudinally in the bolt on the axis of the bolt; drilling a hole, having a small diameter relative to that of the bored hole, transversely in the bolt to intersect the bored hole such that the drilled hole is tangent to the wall of the bored hole at its outer edge and intersects the bored hole at the midpoint of the depth of the bored hole; selecting a bar having a diameter which fits snugly in the bored hole; cutting a groove around the bar, the groove having a depth and width substantially equal to the diameter of the drilled hole, and being set back from a first end of the bar a distance substantially equal to half the depth of the bored hole; inserting the bar into the bored hole; and pressing a spring pin into the drilled hole.