Pan head full thread machine screws UNF
Unified Screw Threads — UNC, UNF and UNEF Major diameter (inch \ mm) Thread density (d, threads per inch) and thread pitch (p) Preferred cutting tap drill size Coarse (UNC) Fine (UNF) Extra fine (UNEF) d (TPI) p (inch \ mm) d (TPI) p (inch \ mm) d (TPI)