Unless you enjoy multiple trips to the hardware store, a pilot hole is essential for all wood screws. Not only do pilot holes prevent the wood from splitting, but they also reduce the likelihood of breaking the screw. Thus, drilling pilot holes will help you save on the materials cost and offer a better appearance to your final product.
|
Screw Size |
Hard Wood |
Soft Wood |
Countersink Size |
||
|
Tapered Bit |
Straight Bit |
Tapered Bit |
Straight Bit |
||
|
#2 |
3/32" |
1/16" |
5/64" |
1/16" |
1/4" |
|
#3 |
7/64" |
5/64" |
3/32" |
1/16" |
1/4" |
|
#4 |
7/64" |
5/64" |
3/32" |
1/16" |
1/4" |
|
#5 |
1/8" |
3/32" |
7/64" |
5/64" |
5/16" |
|
#6 |
9/64" |
7/64" |
1/8" |
3/32" |
5/16" |
|
#7 |
5/32" |
7/64" |
9/64" |
3/32" |
5/16" |
|
#8 |
11/64" |
1/8" |
5/32" |
7/64" |
3/8" |
|
#9 |
3/16" |
9/64" |
11/64" |
1/8" |
3/8" |
|
#10 |
13/64" |
9/64" |
3/16" |
1/8" |
7/16" |
|
#12 |
7/32" |
5/32" |
13/64" |
9/64" |
7/16" |
|
#14 |
1/4" |
11/64" |
15/64" |
5/32" |
1/2" |
|
#16 |
9/32" |
3/16" |
17/64" |
11/64" |
9/16" |
|
#18 |
5/16" |
7/32" |
19/64" |
13/64" |
5/8" |
|
#20 |
21/64" |
15/64" |
5/16" |
7/32" |
3/4" |
|
#24 |
3/8" |
17/64" |
3/8" |
1/4" |
3/4" |