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SAE Tap Drill Chart

Common unified national thread sizes (UNC/UNF).

Screw Size	Tap Drill	Fractional Equiv.	Decimal (in.)
#0-80	3/64″	3/64″	0.0469
#1-64	#53	1/16″	0.0595
#1-72	#53	1/16″	0.0595
#2-56	#50	5/64″	0.0700
#2-64	#50	5/64″	0.0700
#3-48	#47	5/64″	0.0785
#3-56	#45	5/64″	0.0820
#4-40	#43	3/32″	0.0890
#4-48	#42	3/32″	0.0935
#5-40	#38	7/64″	0.1015
#5-44	#37	7/64″	0.1040
#6-32	#36	7/64″	0.1065
#6-40	#33	—	0.1130
#8-32	#29	9/64″	0.1360
#8-36	#29	9/64″	0.1360
#10-24	#25	5/32″	0.1495
#10-32	#21	5/32″	0.1590
#12-24	#16	11/64″	0.1770
#12-28	#14	3/16″	0.1820
1/4-20	#7	13/64″	0.2010
1/4-28	#3	7/32″	0.2130
5/16-18	F	1/4″	0.2570
5/16-24	I	17/64″	0.2720
3/8-16	5/16″	5/16″	0.3125
3/8-24	Q	21/64″	0.3320
7/16-14	U	3/8″	0.3680
7/16-20	25/64″	25/64″	0.3906
1/2-13	27/64″	27/64″	0.4219
1/2-20	29/64″	29/64″	0.4531
9/16-12	31/64″	31/64″	0.4844
9/16-18	33/64″	33/64″	0.5156
5/8-11	17/32″	17/32″	0.5312
5/8-18	37/64″	37/64″	0.5781
3/4-10	21/32″	21/32″	0.6562
3/4-16	11/16″	11/16″	0.6875
7/8-9	49/64″	49/64″	0.7656
7/8-14	13/16″	13/16″	0.8125
1-8	7/8″	7/8″	0.8750
1-12	59/64″	59/64″	0.9219

Standard Drill Size Chart

Wire gauge, letter, and fractional sizes.

Drill Size	Decimal (in)	Decimal (mm)
#80	0.0135	0.343
#79	0.0145	0.368
0.40mm	0.0157	0.400
#78	0.0160	0.406
0.45mm	0.0177	0.450
#77	0.0180	0.457
0.50mm	0.0197	0.500
#76	0.0200	0.508
0.55mm	0.0217	0.550
#75	0.0210	0.533
#74	0.0225	0.572
0.60mm	0.0236	0.600
#73	0.0240	0.610
0.65mm	0.0256	0.650
#72	0.0250	0.635
#71	0.0260	0.660
0.70mm	0.0276	0.700
#70	0.0280	0.711
0.75mm	0.0295	0.750
#69	0.0292	0.742
1/32	0.0312	0.794
#68	0.0310	0.787
#67	0.0320	0.813
0.85mm	0.0335	0.850
#66	0.0330	0.838
0.90mm	0.0354	0.900
#65	0.0350	0.889
#64	0.0360	0.914
#63	0.0370	0.940
#62	0.0380	0.965
#61	0.0390	0.991
1.00mm	0.0394	1.000
#60	0.0400	1.016
#59	0.0410	1.041
#58	0.0420	1.067
#57	0.0430	1.092
1.15mm	0.0453	1.150
#56	0.0465	1.181
3/64	0.0469	1.191
#55	0.0520	1.321
#54	0.0550	1.397
#53	0.0595	1.511
1/16	0.0625	1.588
#52	0.0635	1.613
1.65mm	0.0650	1.651
1.70mm	0.0669	1.700
#51	0.0670	1.702
1.75mm	0.0689	1.750
#50	0.0700	1.778
1.80mm	0.0709	1.800
1.85mm	0.0728	1.850
#49	0.0730	1.854
1.90mm	0.0748	1.900
1.95mm	0.0768	1.950
#48	0.0760	1.930
5/64	0.0781	1.984
2.00mm	0.0787	2.000
#47	0.0785	1.994
2.05mm	0.0807	2.050
#46	0.0810	2.057
#45	0.0820	2.083
2.10mm	0.0827	2.100
#44	0.0860	2.184
2.20mm	0.0866	2.200
2.25mm	0.0886	2.250
#43	0.0890	2.261
2.30mm	0.0906	2.300
3/32	0.0938	2.381
#42	0.0935	2.375
2.40mm	0.0945	2.400
#41	0.0960	2.438
#40	0.0980	2.489
2.50mm	0.0984	2.500
#39	0.0995	2.527
#38	0.1015	2.578
#37	0.1040	2.642
#36	0.1065	2.705
7/64	0.1094	2.778
#35	0.1100	2.794
#34	0.1110	2.819
#33	0.1130	2.870
2.90mm	0.1142	2.900
#32	0.1160	2.946
3.00mm	0.1181	3.000
#31	0.1200	3.048
1/8	0.1250	3.175
3.20mm	0.1260	3.200
3.25mm	0.1280	3.251
#30	0.1285	3.264
#29	0.1360	3.454
#28	0.1405	3.569
9/64	0.1406	3.572
#27	0.1440	3.658
#26	0.1470	3.734
#25	0.1495	3.800
#24	0.1520	3.861
#23	0.1540	3.912
5/32	0.1562	3.969
#22	0.1570	3.988
#21	0.1590	4.039
#20	0.1610	4.089
#19	0.1660	4.216
11/64	0.1719	4.366
#18	0.1695	4.305
#17	0.1730	4.394
#16	0.1770	4.496
#15	0.1800	4.572
#14	0.1820	4.623
#13	0.1850	4.699
3/16	0.1875	4.762
#12	0.1890	4.801
#11	0.1910	4.851
#10	0.1935	4.915
#9	0.1960	4.978
#8	0.1990	5.055
#7	0.2010	5.105
13/64	0.2031	5.159
#6	0.2040	5.182
#5	0.2055	5.220
#4	0.2090	5.309
#3	0.2130	5.410
7/32	0.2188	5.556
#2	0.2210	5.613
#1	0.2280	5.791
15/64	0.2344	5.953
A	0.2340	5.944
B	0.2380	6.045
C	0.2420	6.147
D	0.2460	6.248
1/4	0.2500	6.350
E	0.2500	6.350
F	0.2570	6.528
G	0.2610	6.629
17/64	0.2656	6.747
H	0.2660	6.756
I	0.2720	6.909
J	0.2770	7.036
K	0.2810	7.137
9/32	0.2812	7.144
L	0.2900	7.366
M	0.2950	7.493
19/64	0.2969	7.541
N	0.3020	7.671
5/16	0.3125	7.938
O	0.3160	8.026
P	0.3230	8.204
21/64	0.3281	8.334
Q	0.3320	8.433
R	0.3390	8.611
11/32	0.3438	8.731
S	0.3480	8.839
T	0.3580	9.093
23/64	0.3594	9.128
U	0.3680	9.347
3/8	0.3750	9.525
V	0.3770	9.576
W	0.3860	9.804
25/64	0.3906	9.922
X	0.3970	10.084
13/32	0.4062	10.319
Y	0.4040	10.262
Z	0.4130	10.490
27/64	0.4219	10.716
7/16	0.4375	11.112
29/64	0.4531	11.510
15/32	0.4688	11.906
31/64	0.4844	12.303
1/2	0.5000	12.700
33/64	0.5156	13.097
17/32	0.5312	13.494
35/64	0.5469	13.891
9/16	0.5625	14.288
37/64	0.5781	14.684
19/32	0.5938	15.081
39/64	0.6094	15.478
5/8	0.6250	15.875
41/64	0.6406	16.272
21/32	0.6562	16.669
43/64	0.6719	17.066
11/16	0.6875	17.462
45/64	0.7031	17.859
23/32	0.7188	18.256
47/64	0.7344	18.653
3/4	0.7500	19.050
49/64	0.7656	19.447
25/32	0.7812	19.844
51/64	0.7969	20.241
13/16	0.8125	20.638
53/64	0.8281	21.034
27/32	0.8438	21.431
55/64	0.8594	21.828
7/8	0.8750	22.225
57/64	0.8906	22.622
29/32	0.9062	23.019
59/64	0.9219	23.416
15/16	0.9375	23.812
61/64	0.9531	24.209
31/32	0.9688	24.606
63/64	0.9844	25.003
1	1.0000	25.400

Metric Tap Drill Chart

Common coarse and fine metric thread sizes.

Screw Size (Pitch)	Tap Drill Size	Clearance Drill
M3 x 0.5 (coarse)	2.5mm	3.2mm
M4 x 0.7 (coarse)	3.3mm	4.2mm
M5 x 0.8 (coarse)	4.2mm	5.2mm
M6 x 1.0 (coarse)	5.0mm	6.2mm
M8 x 1.25 (coarse)	6.8mm	8.2mm
M8 x 1.0 (fine)	7.0mm	8.2mm
M10 x 1.5 (coarse)	8.5mm	10.2mm
M10 x 1.25 (fine)	8.8mm	10.2mm
M10 x 1.0 (fine)	9.0mm	10.2mm
M12 x 1.75 (coarse)	10.2mm	12.2mm
M12 x 1.5 (fine)	10.5mm	12.2mm
M12 x 1.25 (fine)	10.8mm	12.2mm
M14 x 2.0 (coarse)	12.0mm	14.5mm
M14 x 1.5 (fine)	12.5mm	14.5mm
M16 x 2.0 (coarse)	14.0mm	16.5mm
M16 x 1.5 (fine)	14.5mm	16.5mm
M18 x 2.5 (coarse)	15.5mm	18.5mm
M18 x 1.5 (fine)	16.5mm	18.5mm
M20 x 2.5 (coarse)	17.5mm	20.5mm
M20 x 1.5 (fine)	18.5mm	20.5mm
M22 x 2.5 (coarse)	19.5mm	22.5mm
M22 x 1.5 (fine)	20.5mm	22.5mm
M24 x 3.0 (coarse)	21.0mm	24.5mm
M24 x 2.0 (fine)	22.0mm	24.5mm

NPT Pipe Thread Chart

National Pipe Thread (NPT) sizes.

NPT	Major Diameter (mm)	Tapping Drill Size (mm)	Threads Per Inch	Pitch (mm)
1/16"	7.895	6.00	27	0.941
1/8"	10.242	8.25	27	0.941
1/4"	13.616	10.70	18	1.411
3/8"	17.055	14.10	18	1.411
1/2"	21.223	17.40	14	1.814
3/4"	26.568	22.60	14	1.814
1"	33.228	28.50	11.5	2.209
1¼"	41.985	37.00	11.5	2.209
1½"	48.054	43.50	11.5	2.209
2"	60.092	55.00	11.5	2.209
2½"	72.699	65.50	8	3.175
3"	88.608	81.50	8	3.175
3½"	101.316	94.30	8	3.175
4"	113.973	107.00	8	3.175
5"	141.300	134.384	8	3.175
6"	168.275	161.191	8	3.175
8"	219.075	211.673	8	3.175
10"	273.050	265.311	8	3.175
12"	323.850	315.793	8	3.175

Imperial Fastener Torque Specs (ft-lbs)

Recommended torque for clean and dry Imperial fasteners.

Size	Grade 2		Grade 5		Grade 8		18-8 S/S
Size	Coarse	Fine	Coarse	Fine	Coarse	Fine	Coarse	Fine
1/4	4	4.7	6.3	7.3	9	10	6.3	7.8
5/16	8	9	13	14	18	20	11	11.8
3/8	15	17	23	26	33	37	20	22
7/16	24	27	37	41	52	58	31	33
1/2	37	41	57	64	80	90	43	45
9/16	53	59	82	91	115	129	57	63
5/8	73	83	112	128	159	180	93	104
3/4	125	138	200	223	282	315	128	124
7/8	129	144	322	355	454	501	194	193
1	188	210	483	541	682	764	287	289

Metric Fastener Torque Specs (ft-lbs)

Recommended torque for clean and dry Metric fasteners.

Size	Class 8.8		Class 10.9		Class 12.9
Size	Coarse	Fine	Coarse	Fine	Coarse	Fine
M6	7.7	7.7	11	11	13	13
M8	19	19	26	28	31	33
M10	37	38	53	53	64	64
M12	65	70	92	99	110	118
M14	103	110	146	154	177	184
M16	158	165	224	232	269	280
M20	309	339	435	472	523	567