Tap and Clearance Hole Chart – Imperial

Imperial Drill Chart							NightShade Electronics nightshade.net
Machine Screw Size			Tap Drills				Clearance Hole Diameters
			Aluminum Brass & Plastic 75% Thread		Stainless Steel Steels & Iron 50% Thread		All Materials

							Close Fit		Free Fit
Name	Major Dia. (in)	Threads Per Inch	American Drill Size	Decimal Equiv. (in)	American Drill Size	Decimal Equiv. (in)	American Drill Size	Decimal Equiv.	American Drill Size	Decimal Equiv.

#0	.0600	80	3/64	.0469	55	.0520	52	.0635	50	.0700
#1	.0730	64	53	.0595	1/16	.0625	48	.0760	46	.0810
		72	53	.0595	52	.0635
#2	.0860	56	50	.0700	49	.0730	43	.0890	41	.0960
		64	50	.0700	48	.0760
#3	.0990	48	47	.0785	44	.0860	37	.1040	35	.1100
		56	45	.0820	43	.0890
#4	.1120	40	43	.0890	41	.0960	32	.1160	30	.1285
		48	42	.0935	40	.0980
#5	.1250	40	38	.1015	7/64	.1094	30	.1285	29	.1360
		44	37	.1040	35	.1100
#6	.1380	32	36	.1065	32	.1160	27	.1440	25	.1495
		40	33	.1130	31	.1200
#8	.1640	32	29	.1360	27	.1440	18	.1695	16	.177
		36	29	.1360	26	.1470
#10	.1900	24	25	.1495	20	.1610	9	.1960	7	.2010
		32	21	.1590	18	.1695
#12	.2160	24	16	.1770	12	.1890	2	.2210	1	.2280
		28	14	.1820	10	.1935
		32	13	.1850	9	.1960
1/4	.2500	20	7	.2010	7/32	.2188	F	.2570	H	.2660
		28	3	.2130	1	.2280
		32	7/32	.2188	1	.2280
5/16	.3125	18	F	.2570	J	.2770	P	.3230	Q	.3320
		24	I	.2720	9/32	.2812
		32	9/32	.2812	L	.2900
3/8	.3750	16	5/16	.3125	Q	.3320	W	.3860	X	.3970
		24	Q	.3320	S	.3480
		32	11/32	.3438	T	.3580
7/16	.4375	14	U	.3680	25/64	.3906	29/64	.4531	15/32	.4687
		20	25/64	.3906	13/32	.4062
		28	Y	.4040	Z	.4130
1/2	.5000	13	27/64	.4219	29/64	.4531	33/64	.5156	17/32	.5312
		20	29/64	.4531	15/32	.4688
		28	15/32	.4688	15/32	.4688
9/16	.5625	12	31/64	.4844	33/64	.5156	37/64	.5781	19/32	.5938
		18	33/64	.5156	17/32	.5312
		24	33/64	.5156	17/32	.5312
5/8	.6250	11	17/32	.5312	9/16	.5625	41/64	.6406	2132	.6562
		18	37/64	.5781	19/32	.5938
		24	37/64	.5781	19/32	.5938
11/16	.6875	24	41/64	.6406	21/32	.6562	45/64	.7031	23/32	.7188
3/4	.7500	10	21/32	.6562	11/16	.6875	49/64	.7656	25/32	.7812
		16	11/16	.6875	45/64	.7031
		20	45/64	.7031	23/32	.7188
13/16	.8125	20	49/64	.7656	25/32	.7812	53/94	.8281	27/32	.8438
7/8	.8750	9	49/64	.7656	51/64	.7969	57/64	.8906	29/32	.9062
		14	13/16	.8125	53/64	.8281
		20	53/64	.8281	27/32	.8438
15/16	0.9375	20	57/64	0.8906	29/32	0.9062	61/64	.9531	31/32	.9688
1	1.00	8	7/8	.8750	59/64	.9219	1-1/64	1.0156	1-1/32	1.0313
		12	15/16	.9375	61/64	.9531
		20	61/64	.9531	31/32	.9688