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Wood Screw Pilot Holes & Countersink Sizes & Driver Bit Sizes
Screw
Size		 Untapered Pilot Hole Size Counter-
sink Size		 Driver Bit Size
Body
(Cut)		 Body
(Rolled)		 Soft Wood Hard Wood Phillips Square
0 1/16 3/64 1/64 1/32 1/4 0 -
1 5/64 1/16 1/32 1/32 1/4 0 -
2 5/64 1/16 1/32 3/64 1/4 1 -
3 3/32 5/64 3/64 1/16 1/4 1 0
4 7/64 3/32 3/64 1/16 1/4 1 0
5 1/8 3/32 1/16 5/64 3/8 2 1
6 9/64 7/64 1/16 5/64 3/8 2 1
7 5/32 1/8 1/16 3/32 3/8 2 1
8 5/32 1/8 5/64 3/32 3/8 2 2
9 11/64 9/64 5/64 7/64 3/8 2 2
10 3/16 5/32 3/32 7/64 1/2 3FO/2R 2
12 7/32 11/64 7/64 1/8 1/2 3 3
14 15/64 13/64 7/64 9/64 5/8 3 3
16 17/64 13/64 9/64 5/32 5/8 3 -
18 19/64 15/64 9/64 3/16 3/4 4 -
20 5/16 1/4 11/64 13/64 3/4 4 -
24 3/8 19/64 3/16 7/32 1 4 -
NOTES:
1. Unless noted otherwise, all dimensions are in inches.
2. Use #3 Phillips driver bit for #10 flat and oval heads and #2 bit for #10 round heads.
3. Body pilot hole size is average body diameter of screw, based on Cut or Rolled
    threads, rounded to nearest 64th.
4. Countersink size is maximum head diameter rounded up to nearest 8th (#0 and
    #24 rounded up to nearest 4th).
5. For reference only.