I believe the thread pitch was for a standard m4 machine screw. I didn't measure it but the m4 DMC screws fit. Unfortunately, that's not a typical Lowes or Ace item. I got them at a local DIY Mecca.... Skycraft Parts and Surplus. You could call them to see if they still have them. They are a surplus store so their inventory changes. Or you can find them on eBay, etc.
Also, if you don't have a special tool, you can use a bolt, 2 washers, and a nut to set them.
Dana
1981 DeLorean DMC-12 (5 Speed, Gas Flap, Black Interior, Windshield Antenna, Dark Gray)
Restored as "mostly correct, but with flaws corrected". Pictures and comments of my restoration are in the albums section on my profile.
1985 Chevrolet Corvette, Z51, 4+3 manual
2006 Dodge Magnum R/T (D/D)
2010 Camaro SS (Transformers Edition)