Encyclopedia & FAQ's

DIY Frequently Asked Questions / Machine Screw


  • DIY Frequently Asked Questions / Machine Screw')"> Can have round, oval, flat and fillister heads.
  • Intended to be screwed into pre-threaded holes in metal.
  • May look like a bolt, but user drives it with a screwdriver instead of a wrench.
  • Comes in coarse (24 threads per inch) and fine (32 threads per inch) sizes.
  • They are sized according to diameter, thread and length. Example: a 6-32×3/4 means the screw has a 6-gauge diameter with 32 threads per inch and is 3/4” long.
  • The round head type is most commonly used. The flat head type is used when the top must be flush with the surface.
  • Oval heads are used in countersunk holes. Fillister heads are used in counter-bored holes.