Tap & Drill Size Chart

Unified National (Inch) Taps

Tap Size	TPI	Major Dia (in)	75% Drill	50% Drill	Close Fit Drill
#0-80	80	.0600	3/64	55	52
#1-64	64	.0730	53	1/16	48
#1-72	72	.0730	53	52	48
#2-56	56	.0860	50	49	43
#2-64	64	.0860	50	48	43
#3-48	48	.0990	47	44	37
#4-40	40	.1120	43	41	32
#4-48	48	.1120	42	40	32
#5-40	40	.1250	38	35	30
#5-44	44	.1250	37	34	30
#6-32	32	.1380	36	32	27
#6-40	40	.1380	33	31	27
#8-32	32	.1640	29	27	18
#8-36	36	.1640	29	26	18
#10-24	24	.1900	25	20	9
#10-32	32	.1900	21	16	9
#12-24	24	.2160	16	12	2
#12-28	28	.2160	14	10	2
1/4-20	20	.2500	#7	#3	F
1/4-28	28	.2500	#3	1	F
5/16-18	18	.3125	F	J	Q
5/16-24	24	.3125	I	K	Q
3/8-16	16	.3750	5/16	T	W
3/8-24	24	.3750	Q	S	W
7/16-14	14	.4375	U	25/64	29/64
7/16-20	20	.4375	25/64	13/32	29/64
1/2-13	13	.5000	27/64	29/64	33/64
1/2-20	20	.5000	29/64	15/32	33/64
9/16-12	12	.5625	31/64	33/64	37/64
9/16-18	18	.5625	33/64	17/32	37/64
5/8-11	11	.6250	17/32	9/16	41/64
5/8-18	18	.6250	37/64	19/32	41/64
3/4-10	10	.7500	21/32	11/16	49/64
3/4-16	16	.7500	11/16	45/64	49/64
7/8-9	9	.8750	49/64	51/64	57/64
7/8-14	14	.8750	13/16	53/64	57/64
1-8	8	1.0000	7/8	59/64	1-1/64
1-12	12	1.0000	15/16	61/64	1-1/64

Tap Size	Pitch (mm)	Major Dia (mm)	75% Drill (mm)	Close Fit Drill (mm)
M1.6×0.35	0.35	1.60	1.25	1.70
M2×0.4	0.40	2.00	1.60	2.10
M2.5×0.45	0.45	2.50	2.05	2.65
M3×0.5	0.50	3.00	2.50	3.15
M4×0.7	0.70	4.00	3.30	4.20
M5×0.8	0.80	5.00	4.20	5.25
M6×1.0	1.00	6.00	5.00	6.30
M8×1.25	1.25	8.00	6.75	8.40
M10×1.5	1.50	10.00	8.50	10.50
M12×1.75	1.75	12.00	10.20	12.50
M14×2.0	2.00	14.00	12.00	14.50
M16×2.0	2.00	16.00	14.00	16.50
M18×2.5	2.50	18.00	15.50	18.50
M20×2.5	2.50	20.00	17.50	20.50
M22×2.5	2.50	22.00	19.50	22.50
M24×3.0	3.00	24.00	21.00	24.50