Stanley Hardware

From Wayne's Dusty Box of Words
  • Cap Iron screw: 5/16-18 BSW
  • Frog screws: #12-20
  • Tote & Knob bolts: #12-20
  • Tote Toe screw: #12-20
  • Frog Adjusting Plate screw: #12-24
  • Frog Adjusting screw: 1/4-24 American/Unified;
  • Brass Adjusting nut: 9/32-24 American/Unified (left-hand thread);
  • Lever Cap screw: 9/32-24 American/Unified.
  • Much of the rest on planes is also #12-20

If you do a lot of restoration, it's probably worth your while to track down a tap & die in #12-20. It's pretty rare, but you do come across them occasionally.