Printable Tap Drill Chart (PDF)

Three pages, sized for US Letter and A4. The units switch changes the decimals only; drill designations stay the same.

Inch Tap & Clearance Drill Sizes UNC / UNF / UNEF · Decimals in millimeters				Tap drill				Clearance drill
				75% thread for aluminum, brass & plastics		50% thread for steel, stainless & iron		Close fit		Free fit
Screw size	Major dia.	Threads per inch	Minor dia.	Drill	Dec.	Drill	Dec.	Drill	Dec.	Drill	Dec.
#0	1.524	80	1.135	3/64	1.191	#55	1.321	#52	1.613	#50	1.778
#1	1.854	64	1.367	#53	1.511	1/16	1.587	#48	1.930	#46	2.057
#1	1.854	72	1.422	#53	1.511	#52	1.613	#48	1.930	#46	2.057
#2	2.184	56	1.628	#50	1.778	#49	1.854	#43	2.261	#41	2.438
#2	2.184	64	1.697	#50	1.778	#48	1.930	#43	2.261	#41	2.438
#3	2.515	48	1.864	#47	1.994	#44	2.184	#37	2.642	#35	2.794
#3	2.515	56	1.958	#45	2.083	#43	2.261	#37	2.642	#35	2.794
#4	2.845	40	2.065	#43	2.261	#41	2.438	#32	2.946	#30	3.264
#4	2.845	48	2.195	#42	2.375	#40	2.489	#32	2.946	#30	3.264
#5	3.175	40	2.395	#38	2.578	7/64	2.779	#30	3.264	#29	3.454
#5	3.175	44	2.466	#37	2.642	#35	2.794	#30	3.264	#29	3.454
#6	3.505	32	2.532	#36	2.705	#32	2.946	#27	3.658	#25	3.797
#6	3.505	40	2.725	#33	2.870	#31	3.048	#27	3.658	#25	3.797
#8	4.166	32	3.193	#29	3.454	#27	3.658	#18	4.305	#16	4.496
#8	4.166	36	3.299	#29	3.454	#26	3.734	#18	4.305	#16	4.496
#10	4.826	24	3.528	#25	3.797	#20	4.089	#9	4.978	#7	5.105
#10	4.826	32	3.853	#21	4.039	#18	4.305	#9	4.978	#7	5.105
#12	5.486	24	4.188	#16	4.496	#12	4.801	#2	5.613	#1	5.791
		28	4.374	#14	4.623	#10	4.915
		32	4.514	#13	4.699	#9	4.978
1/4"	6.350	20	4.793	#7	5.105	7/32	5.558	F	6.528	H	6.756
		28	5.237	#3	5.410	#1	5.791
		32	5.377	7/32	5.558	#1	5.791
5/16"	7.938	18	6.205	F	6.528	J	7.036	P	8.204	Q	8.433
		24	6.640	I	6.909	9/32	7.142
		32	6.965	9/32	7.142	L	7.366
3/8"	9.525	16	7.577	5/16	7.938	Q	8.433	W	9.804	X	10.084
		24	8.227	Q	8.433	S	8.839
		32	8.552	11/32	8.733	T	9.093
7/16"	11.112	14	8.887	U	9.347	25/64	9.921	29/64	11.509	15/32	11.905
		20	9.555	25/64	9.921	13/32	10.317
		28	10.000	Y	10.262	Z	10.490
1/2"	12.700	13	10.302	27/64	10.716	29/64	11.509	33/64	13.096	17/32	13.492
		20	11.143	29/64	11.509	15/32	11.908
		28	11.587	15/32	11.908	15/32	11.908
9/16"	14.287	12	11.692	31/64	12.304	33/64	13.096	37/64	14.684	19/32	15.083
		18	12.555	33/64	13.096	17/32	13.492
		24	12.990	33/64	13.096	17/32	13.492
5/8"	15.875	11	13.043	17/32	13.492	9/16	14.287	41/64	16.271	21/32	16.667
		18	14.143	37/64	14.684	19/32	15.083
		24	14.577	37/64	14.684	19/32	15.083
11/16"	17.462	24	16.165	41/64	16.271	21/32	16.667	45/64	17.859	23/32	18.258
3/4"	19.050	10	15.933	21/32	16.667	11/16	17.462	49/64	19.446	25/32	19.842
		16	17.102	11/16	17.462	45/64	17.859
		20	17.493	45/64	17.859	23/32	18.258
13/16"	20.637	20	19.080	49/64	19.446	25/32	19.842	53/64	21.034	27/32	21.433
7/8"	22.225	9	18.763	49/64	19.446	51/64	20.241	57/64	22.621	29/32	23.017
		14	20.000	13/16	20.637	53/64	21.034
		20	20.668	53/64	21.034	27/32	21.433
15/16"	23.813	20	22.255	57/64	22.621	29/32	23.017	61/64	24.209	31/32	24.608
1"	25.400	8	21.504	7/8	22.225	59/64	23.416	1-1/64	25.796	1-1/32	26.195
		12	22.804	15/16	23.813	61/64	24.209
		20	23.843	61/64	24.209	31/32	24.608

Metric Tap & Clearance Drill Sizes ISO 261 coarse & fine · Decimals in millimeters				Tap drill				Clearance drill
				75% thread for aluminum, brass & plastics		50% thread for steel, stainless & iron		Close fit		Free fit
Screw size	Major dia.	Pitch (mm)	Minor dia.	Drill	Dec.	Drill	Dec.	Drill	Dec.	Drill	Dec.
M1.5	1.500	0.35	1.121	1.15 mm	1.150	1.25 mm	1.250	1.6 mm	1.600	1.65 mm	1.650
M1.6	1.600	0.35	1.221	1.25 mm	1.250	1.25 mm	1.250	1.7 mm	1.700	1.8 mm	1.800
M1.8	1.800	0.35	1.421	1.45 mm	1.450	1.55 mm	1.550	1.9 mm	1.900	2.0 mm	2.000
M2	2.000	0.4	1.567	1.6 mm	1.600	1.6 mm	1.600	2.2 mm	2.200	2.4 mm	2.400
M2	2.000	0.45	1.513	1.55 mm	1.550	1.7 mm	1.700	2.2 mm	2.200	2.4 mm	2.400
M2.2	2.200	0.45	1.713	1.75 mm	1.750	1.9 mm	1.900	2.3 mm	2.300	2.4 mm	2.400
M2.5	2.500	0.45	2.013	2.05 mm	2.050	2.05 mm	2.050	2.7 mm	2.700	2.9 mm	2.900
M3	3.000	0.5	2.459	2.5 mm	2.500	2.5 mm	2.500	3.2 mm	3.200	3.4 mm	3.400
M3	3.000	0.6	2.351	2.4 mm	2.400	2.6 mm	2.600	3.2 mm	3.200	3.4 mm	3.400
M3.5	3.500	0.6	2.851	2.9 mm	2.900	2.9 mm	2.900	3.7 mm	3.700	3.9 mm	3.900
M4	4.000	0.7	3.242	3.3 mm	3.300	3.3 mm	3.300	4.3 mm	4.300	4.5 mm	4.500
M4	4.000	0.75	3.188	3.25 mm	3.250	3.5 mm	3.500	4.3 mm	4.300	4.5 mm	4.500
M4.5	4.500	0.75	3.688	3.75 mm	3.750	4.0 mm	4.000	4.75 mm	4.750	5.0 mm	5.000
M5	5.000	0.8	4.134	4.2 mm	4.200	4.2 mm	4.200	5.3 mm	5.300	5.5 mm	5.500
		1.0	3.917	4.0 mm	4.000	4.4 mm	4.400
		0.9	4.026	4.1 mm	4.100	4.4 mm	4.400
M5.5	5.500	0.9	4.526	4.6 mm	4.600	4.9 mm	4.900	5.8 mm	5.800	6.1 mm	6.100
M6	6.000	1.0	4.918	5.0 mm	5.000	5.0 mm	5.000	6.4 mm	6.400	6.6 mm	6.600
M6	6.000	0.75	5.188	5.25 mm	5.250	5.5 mm	5.500	6.4 mm	6.400	6.6 mm	6.600
M7	7.000	1.0	5.918	6.0 mm	6.000	6.4 mm	6.400	7.4 mm	7.400	7.7 mm	7.700
M7	7.000	0.75	6.188	6.25 mm	6.250	6.5 mm	6.500	7.4 mm	7.400	7.7 mm	7.700
M8	8.000	1.25	6.647	6.8 mm	6.800	6.8 mm	6.800	8.4 mm	8.400	9.0 mm	9.000
M8	8.000	1.0	6.918	7.0 mm	7.000	7.4 mm	7.400	8.4 mm	8.400	9.0 mm	9.000
M9	9.000	1.25	7.647	7.8 mm	7.800	8.2 mm	8.200	9.5 mm	9.500	9.9 mm	9.900
M9	9.000	1.0	7.918	8.0 mm	8.000	8.4 mm	8.400	9.5 mm	9.500	9.9 mm	9.900
M10	10.000	1.5	8.376	8.5 mm	8.500	8.5 mm	8.500	10.5 mm	10.500	11.0 mm	11.000
		1.25	8.647	8.8 mm	8.800	9.2 mm	9.200
		1.0	8.918	9.0 mm	9.000	9.4 mm	9.400
M11	11.000	1.5	9.376	9.5 mm	9.500	10.0 mm	10.000	11.6 mm	11.600	12.1 mm	12.100
M12	12.000	1.75	10.106	10.2 mm	10.200	10.2 mm	10.200	13.0 mm	13.000	13.5 mm	13.500
		1.5	10.376	10.5 mm	10.500	11.0 mm	11.000
		1.25	10.647	10.8 mm	10.800	11.2 mm	11.200
M14	14.000	2.0	11.835	12.1 mm	12.100	12.7 mm	12.700	14.75 mm	14.750	15.5 mm	15.500
		1.5	12.376	12.5 mm	12.500	13.0 mm	13.000
		1.25	12.647	12.8 mm	12.800	13.2 mm	13.200
M15	15.000	1.5	13.376	13.5 mm	13.500	14.0 mm	14.000	15.75 mm	15.750	16.5 mm	16.500
M16	16.000	2.0	13.835	14.0 mm	14.000	14.75 mm	14.750	16.75 mm	16.750	17.5 mm	17.500
M16	16.000	1.5	14.376	14.5 mm	14.500	15.0 mm	15.000	16.75 mm	16.750	17.5 mm	17.500
M17	17.000	1.5	15.376	15.5 mm	15.500	16.0 mm	16.000	18.0 mm	18.000	18.5 mm	18.500
M18	18.000	2.5	15.294	15.5 mm	15.500	16.5 mm	16.500	19.0 mm	19.000	20.0 mm	20.000
		2.0	15.835	16.0 mm	16.000	16.75 mm	16.750
		1.5	16.376	16.5 mm	16.500	17.0 mm	17.000
M19	19.000	2.5	16.294	16.5 mm	16.500	17.5 mm	17.500	20.0 mm	20.000	21.0 mm	21.000
M20	20.000	2.5	17.294	17.5 mm	17.500	18.5 mm	18.500	21.0 mm	21.000	22.0 mm	22.000
		2.0	17.835	18.0 mm	18.000	18.5 mm	18.500
		1.5	18.376	18.5 mm	18.500	19.0 mm	19.000

Drill Size Decimal Equivalents

Decimals in millimeters

Number drills

Drill	Dec.
#1	5.791
#2	5.613
#3	5.410
#4	5.309
#5	5.220
#6	5.182
#7	5.105
#8	5.055
#9	4.978
#10	4.915
#11	4.851
#12	4.801
#13	4.699
#14	4.623
#15	4.572
#16	4.496
#17	4.394
#18	4.305
#19	4.216
#20	4.089
#21	4.039
#22	3.988
#23	3.912
#24	3.861
#25	3.797
#26	3.734
#27	3.658

Drill	Dec.
#28	3.569
#29	3.454
#30	3.264
#31	3.048
#32	2.946
#33	2.870
#34	2.819
#35	2.794
#36	2.705
#37	2.642
#38	2.578
#39	2.527
#40	2.489
#41	2.438
#42	2.375
#43	2.261
#44	2.184
#45	2.083
#46	2.057
#47	1.994
#48	1.930
#49	1.854
#50	1.778
#51	1.702
#52	1.613
#53	1.511
#54	1.397

Drill	Dec.
#55	1.321
#56	1.181
#57	1.092
#58	1.067
#59	1.041
#60	1.016
#61	0.991
#62	0.965
#63	0.940
#64	0.914
#65	0.889
#66	0.838
#67	0.813
#68	0.787
#69	0.742
#70	0.711
#71	0.660
#72	0.635
#73	0.610
#74	0.571
#75	0.533
#76	0.508
#77	0.457
#78	0.406
#79	0.368
#80	0.343

Letter drills

Drill	Dec.
A	5.944
B	6.045
C	6.147
D	6.248
E	6.350
F	6.528
G	6.629
H	6.756
I	6.909
J	7.036
K	7.137
L	7.366
M	7.493

Drill	Dec.
N	7.671
O	8.026
P	8.204
Q	8.433
R	8.611
S	8.839
T	9.093
U	9.347
V	9.576
W	9.804
X	10.084
Y	10.262
Z	10.490

Fractional drills

Drill	Dec.
1/64	0.397
1/32	0.794
3/64	1.191
1/16	1.587
5/64	1.984
3/32	2.381
7/64	2.778
1/8	3.175
9/64	3.572
5/32	3.969
11/64	4.366
3/16	4.762
13/64	5.159
7/32	5.556
15/64	5.953
1/4	6.350

Drill	Dec.
17/64	6.747
9/32	7.144
19/64	7.541
5/16	7.938
21/64	8.334
11/32	8.731
23/64	9.128
3/8	9.525
25/64	9.922
13/32	10.319
27/64	10.716
7/16	11.112
29/64	11.509
15/32	11.906
31/64	12.303
1/2	12.700

Inch Tap &Clearance Drill Sizes

Metric Tap &Clearance Drill Sizes

Drill Size Decimal Equivalents

Inch Tap &
Clearance Drill Sizes

Metric Tap &
Clearance Drill Sizes