US Wood Screws - Pilot Holes

Hard wood and soft wood pilot holes, shank clearance holes and countersink diameters for US wood screws.

Nominal Size No.	Nominal Shank Diameter (in)	Actual Shank Diameter (in)	Hard Wood Pilot Hole (Twist Drill)	Hard Wood Pilot Hole (No.)	Soft Wood Pilot Hole (in)	Soft Wood Pilot Hole (No.)	Shank Clearance Hole (in)	Shank Clearance Hole (No.)	Actual Head Diameter (in)	80° Countersink Diameter (in)
0	0.06	0.064	3/64	58	1/32	69	1/16	52	0.119	0.125
1	0.073	0.077	3/64	55	1/32	65	5/64	47	0.146	0.1875
2	0.086	0.09	1/16	53	3/64	59	3/32	42	0.172	0.1875
3	0.099	0.103	1/16	51	3/64	56	7/64	37	0.199	0.25
4	0.112	0.116	5/64	48	3/64	55	7/64	32	0.225	0.25
5	0.125	0.129	5/64	44	1/16	53	1/8	30	0.252	0.25
6	0.138	0.142	3/32	42	1/16	52	9/64	27	0.279	0.375
7	0.151	0.155	3/32	38	1/16	50	5/32	22	0.305	0.375
8	0.164	0.168	7/64	35	5/64	48	11/64	18	0.332	0.375
9	0.177	0.181	1/8	32	5/64	46	3/16	14	0.358	0.375
10	0.19	0.194	1/8	30	3/32	44	3/16	10	0.385	0.5
11	0.203	0.207	1/8	29	3/32	43	13/64	4	0.412	0.5
12	0.216	0.22	9/64	27	3/32	39	7/32	2	0.438	0.5
14	0.242	0.246	5/32	20	7/64	34	1/4	D	0.507	0.5
16	0.268	0.272	3/16	16	1/8	31	17/64	I	0.544	0.625
18	0.294	0.298	3/16	10	9/64	29	19/64	N	0.635	0.625
20	0.32	0.324	7/32	3	5/32	26	21/64	P	0.65	0.75
24	0.372	0.376	1/4	D	11/64	18	3/8	V	0.762	0.75