Shoulder bolt specifications call out the shoulder diameter, shoulder length, and threaded diameter; the threaded length is fixed, based on the threaded diameter, and usually quite short. Shoulder Screw, 24 (Coarse) Thr Sz, 3/8 in Thr Lg, 1-1/4 in Shoulder Lg, Steel, 3 PK. It is usually used for revolving joints in mechanisms and linkages; when used as a guide for the stripper plate in a die set its called a stripper bolt.
A self-drilling screw, or tek screw, is similar to a sheet metal screw, but it has a drill-shaped point to cut through the substrate to eliminate the need for drilling a pilot hole.