Standard Series Internal Unified Screw Threads Class 2
Unified Screw Thread	Min Tap Drill Size	Tap Drill	Max Tap Drill Size	Major Diameter	Clearance Drill
					Drill	Size
					#97, 0.15mm	0.0059
					#96, 0.16mm	0.0063
					#95, 0.17mm	0.0067
					#94, 0.18mm	0.0071
					#93, 0.19mm	0.0075
					#92, 0.20mm	0.0079
					#91	0.0083
					#90, 0.22mm	0.0087
					#89	0.0091
					#88	0.0095
					0.25mm	0.0098
					#87	0.0100
					#86	0.0105
					#85, 0.28mm	0.0110
					#84	0.0115
					0.30mm	0.0118
					#83	0.0120
					#82	0.0125
					0.32mm	0.0126
					#81	0.0130
					#80	0.0135
					0.35mm	0.0138
					#79	0.0145
					0.38mm	0.0150
					1/64	0.0156
					0.40mm	0.0157
					#78	0.0160
					0.42mm	0.0165
					0.45mm	0.0177

Standard Series Internal Unified Screw Threads Class 2
Unified Screw Thread	Min Tap Drill Size	Tap Drill	Max Tap Drill Size	Major Diameter	Clearance Drill
					Drill	Size
					#77	0.0180
					0.48mm	0.0189
					0.50mm	0.0197
					#76	0.0200
					#75	0.0210
					0.55mm	0.0217
					#74	0.0225
					0.60mm	0.0236
					#73	0.0240
					#72	0.0250
					0.65mm	0.0256
					#71	0.0260
					0.70mm	0.0276
					#70	0.0280
					#69	0.0292
					0.75mm	0.0295
					#68	0.0310
					1/32	0.0312
					0.80mm	0.0315
					#67	0.0320
					#66	0.0330
					0.85mm	0.0335
					#65	0.0350
					0.90mm	0.0354
					#64	0.0360
					#63	0.0370
					0.95mm	0.0374
					#62	0.0380
					#61	0.0390

Standard Series Internal Unified Screw Threads Class 2
Unified Screw Thread	Min Tap Drill Size	Tap Drill	Max Tap Drill Size	Major Diameter	Clearance Drill
					Drill	Size
					1.00mm	0.0394
					#60	0.0400
					#59	0.0410
					1.05mm	0.0413
					#58	0.0420
					#57	0.0430
					1.10mm	0.0433
					1.15mm	0.0453
					#56	0.0465
					3/64	0.0469
					1.20mm	0.0472
					1.25mm	0.0492
					1.30mm	0.0512
					#55	0.0520
					1.35mm	0.0531
					#54	0.0550
					1.40mm	0.0551
					1.45mm	0.0571
					1.50mm	0.0591
					#53	0.0595
					1.55mm	0.0610
0-80 UNF	0.0465	3/64	0.0514	0.0600	1/16	0.0625
M1.6 × 0.35	1.221mm	1.25mm	1.321mm	1.60mm	1.60mm	0.0630
					#52	0.0635
					1.65mm	0.0650
					1.70mm	0.0669
					#51	0.0670
					1.75mm	0.0689
					#50	0.0700

Standard Series Internal Unified Screw Threads Class 2
Unified Screw Thread	Min Tap Drill Size	Tap Drill	Max Tap Drill Size	Major Diameter	Clearance Drill
					Drill	Size
					1.80mm	0.0709
					1.85mm	0.0728
1-64 UNC	0.0561	#53	0.0623	0.0730	#49	0.0730
1-72 UNF	0.0580	#53	0.0635	0.0730	#49	0.0730
					1.90mm	0.0748
					#48	0.0760
					1.95mm	0.0768
					5/64	0.0781
					#47	0.0785
M2 × 0.4	1.567mm	1.60mm	1.679mm	2.00mm	2.00mm	0.0787
					2.05mm	0.0807
					#46	0.0810
					#45	0.0820
					2.10mm	0.0827
					2.15mm	0.0846
2-56 UNC	0.0667	#50	0.0737	0.0860	#44	0.0860
2-64 UNF	0.0691	#50	0.0753	0.0860	#44	0.0860
					2.20mm	0.0866
					2.25mm	0.0886
					#43	0.0890
					2.30mm	0.0906
					2.35mm	0.0925
					#42	0.0935
					3/32	0.0938
					2.40mm	0.0945
					#41	0.0960
					2.45mm	0.0965
					#40	0.0980
M2.5 × 0.45	2.013mm	2.05mm	2.138mm	2.50mm	2.50mm	0.0984

Standard Series Internal Unified Screw Threads Class 2
Unified Screw Thread	Min Tap Drill Size	Tap Drill	Max Tap Drill Size	Major Diameter	Clearance Drill
					Drill	Size
3-48 UNC	0.0764	#47	0.0845	0.0990	#39	0.0995
3-56 UNF	0.0797	#46	0.0865	0.0990	#39	0.0995
					#38	0.1015
					2.60mm	0.1024
					#37	0.1040
					2.70mm	0.1063
					#36	0.1065
					2.75mm	0.1083
					7/64	0.1094
					#35	0.1100
					2.80mm	0.1102
					#34	0.1110
4-40 UNC	0.0849	#43	0.0939	0.1120	#33	0.1130
4-48 UNF	0.0894	#42	0.0968	0.1120	#33	0.1130
					2.90mm	0.1142
					#32	0.1160
M3 × 0.5	2.459mm	2.50mm	2.599mm	3.00mm	3.00mm	0.1181
					#31	0.1200
					3.10mm	0.1220
5-40 UNC	0.0979	#39	0.1062	0.1250	1/8	0.1250
5-44 UNF	0.1004	#38	0.1079	0.1250	1/8	0.1250
					3.20mm	0.1260
					3.25mm	0.1280
					#30	0.1285
					3.30mm	0.1299
					3.40mm	0.1339
					#29	0.1360
M3.5 × 0.6	2.850mm	2.90mm	3.010mm	3.50mm	3.50mm	0.1378

Standard Series Internal Unified Screw Threads Class 2
Unified Screw Thread	Min Tap Drill Size	Tap Drill	Max Tap Drill Size	Major Diameter	Clearance Drill
					Drill	Size
6-32 UNC	0.104	#36	0.114	0.1380	#28	0.1405
6-40 UNF	0.111	#34	0.119	0.1380	#28	0.1405
					9/64	0.1406
					3.60mm	0.1417
					#27	0.1440
					3.70mm	0.1457
					#26	0.1470
					3.75mm	0.1476
					#25	0.1495
					3.80mm	0.1496
					#24	0.1520
					3.90mm	0.1535
					#23	0.1540
					5/32	0.1562
					#22	0.1570
M4 × 0.7	3.242mm	3.30mm	3.422mm	4.00mm	4.00mm	0.1575
					#21	0.1590
					#20	0.1610
					4.10mm	0.1614
					4.20mm	0.1654
8-32 UNC	0.130	#29	0.139	0.1640	#19	0.1660
8-36 UNF	0.134	#29	0.142	0.1640	#19	0.1660
					4.25mm	0.1673
					4.30mm	0.1693
					#18	0.1695
					11/64	0.1719
					#17	0.1730
					4.40mm	0.1732
					#16	0.1770

Standard Series Internal Unified Screw Threads Class 2
Unified Screw Thread	Min Tap Drill Size	Tap Drill	Max Tap Drill Size	Major Diameter	Clearance Drill
					Drill	Size
					4.50mm	0.1772
					#15	0.1800
					4.60mm	0.1811
					#14	0.1820
					#13, 4.70mm	0.1850
					4.75mm	0.1870
					3/16	0.1875
					#12, 4.80mm	0.1890
10-24 UNC	0.145	#26	0.156	0.1900	#11	0.1910
10-28 UNS	0.151	#24	0.160	0.1900	#11	0.1910
10-32 UNF	0.156	5/32	0.164	0.1900	#11	0.1910
10-36 UNS	0.160	#20	0.166	0.1900	#11	0.1910
10-40 UNS	0.163	#19	0.169	0.1900	#11	0.1910
10-48 UNS	0.167	#18	0.172	0.1900	#11	0.1910
10-56 UNS	0.171	11/64	0.175	0.1900	#11	0.1910
					4.90mm	0.1929
					#10	0.1935
					#9	0.1960
M5 × 0.8	4.134mm	4.20mm	4.334mm	5.00mm	5.00mm	0.1969
					#8	0.1990
					5.10mm	0.2008
					#7	0.2010
					13/64	0.2031
					#6	0.2040
					5.20mm	0.2047
					#5	0.2055
					5.25mm	0.2067
					5.30mm	0.2087
					#4	0.2090

Standard Series Internal Unified Screw Threads Class 2
Unified Screw Thread	Min Tap Drill Size	Tap Drill	Max Tap Drill Size	Major Diameter	Clearance Drill
					Drill	Size
					5.40mm	0.2126
					#3	0.2130
					5.50mm	0.2165
12-24 UNC	0.171	11/64	0.181	0.2160	7/32	0.2188
12-28 UNF	0.177	#16	0.186	0.2160	7/32	0.2188
12-32 UNEF	0.182	#14	0.190	0.2160	7/32	0.2188
12-36 UNS	0.186	3/16	0.192	0.2160	7/32	0.2188
12-40 UNS	0.189	#12	0.195	0.2160	7/32	0.2188
12-48 UNS	0.193	#10	0.198	0.2160	7/32	0.2188
12-56 UNS	0.197	#9	0.201	0.2160	7/32	0.2188
					5.60mm	0.2205
					#2	0.2210
					5.70mm	0.2244
					5.75mm	0.2264
					#1	0.2280
					5.80mm	0.2283
					5.90mm	0.2323
					A	0.2340
					15/64	0.2344
M6 × 1	4.917mm	5.00mm	5.153mm	6.00mm	6.00mm	0.2362
					B	0.2380
					6.10mm	0.2402
					C	0.2420
					6.20mm	0.2441
					D	0.2460
					6.25mm	0.2461
					6.30mm	0.2480

Standard Series Internal Unified Screw Threads Class 2
Unified Screw Thread	Min Tap Drill Size	Tap Drill	Max Tap Drill Size	Major Diameter	Clearance Drill
					Drill	Size
1/4-20 UNC	0.196	#9	0.207	0.2500	E, 1/4	0.2500
1/4-24 UNS	0.205	#5	0.215	0.2500	E, 1/4	0.2500
1/4-27 UNS	0.210	#3	0.219	0.2500	E, 1/4	0.2500
1/4-28 UNF	0.211	#3	0.220	0.2500	E, 1/4	0.2500
1/4-32 UNEF	0.216	7/32	0.224	0.2500	E, 1/4	0.2500
1/4-36 UNS	0.220	#2	0.226	0.2500	E, 1/4	0.2500
1/4-40 UNS	0.223	#2	0.229	0.2500	E, 1/4	0.2500
1/4-48 UNS	0.227	#1	0.232	0.2500	E, 1/4	0.2500
1/4-56 UNS	0.231	#1	0.235	0.2500	E, 1/4	0.2500
					6.40mm	0.2520
					6.50mm	0.2559
					F	0.2570
					6.60mm	0.2598
					G	0.2610
					6.70mm	0.2638
					17/64	0.2656
					H	0.2660
					6.80mm	0.2677
					6.90mm	0.2717
					I	0.2720
					7.00mm	0.2756
					J	0.2770
					7.10mm	0.2795
					K	0.2810
					9/32	0.2812
					7.20mm	0.2835
					7.25mm	0.2854
					7.30mm	0.2874
					L	0.2900

Standard Series Internal Unified Screw Threads Class 2
Unified Screw Thread	Min Tap Drill Size	Tap Drill	Max Tap Drill Size	Major Diameter	Clearance Drill
					Drill	Size
					7.40mm	0.2913
					M	0.2950
					7.50mm	0.2953
					19/64	0.2969
					7.60mm	0.2992
					N	0.3020
					7.70mm	0.3031
					7.75mm	0.3051
					7.80mm	0.3071
					7.90mm	0.3110
5/16-18 UNC	0.252	F	0.265	0.3125	5/16	0.3125
5/16-20 UN	0.258	G	0.270	0.3125	5/16	0.3125
5/16-24 UNF	0.267	I	0.277	0.3125	5/16	0.3125
5/16-27 UNS	0.272	I	0.281	0.3125	5/16	0.3125
5/16-28 UN	0.274	J	0.282	0.3125	5/16	0.3125
5/16-32 UNEF	0.279	K	0.286	0.3125	5/16	0.3125
5/16-36 UNS	0.282	9/32	0.289	0.3125	5/16	0.3125
5/16-40 UNS	0.285	9/32	0.291	0.3125	5/16	0.3125
5/16-48 UNS	0.290	L	0.295	0.3125	5/16	0.3125
M8 × 1.25	6.647mm	6.70mm	6.912mm	8.00mm	8.00mm	0.3150
M8 × 1	6.917mm	7.00mm	7.153mm	8.00mm	8.00mm	0.3150
					O	0.3160
					8.10mm	0.3189
					8.20mm	0.3228
					P	0.3230
					8.25mm	0.3248
					8.30mm	0.3268
					21/64	0.3281
					8.40mm	0.3307

Standard Series Internal Unified Screw Threads Class 2
Unified Screw Thread	Min Tap Drill Size	Tap Drill	Max Tap Drill Size	Major Diameter	Clearance Drill
					Drill	Size
					Q	0.3320
					8.50mm	0.3346
					8.60mm	0.3386
					R	0.3390
					8.70mm	0.3425
					11/32	0.3438
					8.75mm	0.3445
					8.80mm	0.3465
					S	0.3480
					8.90mm	0.3504
					9.00mm	0.3543
					T	0.3580
					9.10mm	0.3583
					23/64	0.3594
					9.20mm	0.3622
					9.25mm	0.3642
					9.30mm	0.3661
					U	0.3680
					9.40mm	0.3701
					9.50mm	0.3740
3/8-16 UNC	0.307	5/16	0.321	0.3750	3/8	0.3750
3/8-18 UNS	0.315	O	0.328	0.3750	3/8	0.3750
3/8-20 UN	0.321	P	0.332	0.3750	3/8	0.3750
3/8-24 UNF	0.330	Q	0.340	0.3750	3/8	0.3750
3/8-27 UNS	0.335	R	0.344	0.3750	3/8	0.3750
3/8-28 UN	0.336	R	0.345	0.3750	3/8	0.3750
3/8-32 UNEF	0.341	11/32	0.349	0.3750	3/8	0.3750
3/8-36 UNS	0.345	11/32	0.352	0.3750	3/8	0.3750
3/8-40 UNS	0.348	S	0.354	0.3750	3/8	0.3750

Standard Series Internal Unified Screw Threads Class 2
Unified Screw Thread	Min Tap Drill Size	Tap Drill	Max Tap Drill Size	Major Diameter	Clearance Drill
					Drill	Size
					V	0.3770
					9.60mm	0.3780
					9.70mm	0.3819
					9.75mm	0.3839
					9.80mm	0.3858
					W	0.3860
					9.90mm	0.3898
0.390-27 UNS	0.350	S	0.359	0.3900	25/64	0.3906
M10 × 1.5	8.376mm	8.40mm	8.676mm	10.00mm	10.00mm	0.3937
M10 × 1.25	8.647mm	8.70mm	8.912mm	10.00mm	10.00mm	0.3937
M10 × 0.75	9.188mm	9.20mm	9.378mm	10.00mm	10.00mm	0.3937
					X	0.3970
					10.20mm	0.4016
					Y	0.4040
					13/32	0.4062
					Z	0.4130
					10.50mm	0.4134
					27/64	0.4219
					10.80mm	0.4252
					11.00mm	0.4331
7/16-14 UNC	0.360	U	0.376	0.4375	7/16	0.4375
7/16-16 UN	0.370	3/8	0.384	0.4375	7/16	0.4375
7/16-18 UNS	0.377	V	0.390	0.4375	7/16	0.4375
7/16-20 UNF	0.383	W	0.395	0.4375	7/16	0.4375
7/16-24 UNS	0.392	25/64	0.402	0.4375	7/16	0.4375
7/16-27 UNS	0.397	X	0.406	0.4375	7/16	0.4375
7/16-28 UNEF	0.399	X	0.407	0.4375	7/16	0.4375
7/16-32 UN	0.404	Y	0.411	0.4375	7/16	0.4375
					11.20mm	0.4409

Standard Series Internal Unified Screw Threads Class 2
Unified Screw Thread	Min Tap Drill Size	Tap Drill	Max Tap Drill Size	Major Diameter	Clearance Drill
					Drill	Size
					11.50mm	0.4528
					29/64	0.4531
					11.80mm	0.4646
					15/32	0.4688
M12 × 1.75	10.106mm	10.20mm	10.441mm	12.00mm	12.00mm	0.4724
M12 × 1.5	10.376mm	10.50mm	10.676mm	12.00mm	12.00mm	0.4724
M12 × 1.25	10.647mm	10.80mm	10.912mm	12.00mm	12.00mm	0.4724
M12 × 1	10.917mm	11.00mm	11.153mm	12.00mm	12.00mm	0.4724
					12.20mm	0.4803
					31/64	0.4844
					12.50mm	0.4921
1/2-12 UNS	0.410	Z	0.428	0.5000	1/2	0.5000
1/2-13 UNC	0.417	27/64	0.434	0.5000	1/2	0.5000
1/2-14 UNS	0.423	27/64	0.438	0.5000	1/2	0.5000
1/2-16 UN	0.432	7/16	0.446	0.5000	1/2	0.5000
1/2-18 UNS	0.440	7/16	0.453	0.5000	1/2	0.5000
1/2-20 UNF	0.446	29/64	0.457	0.5000	1/2	0.5000
1/2-24 UNS	0.455	29/64	0.465	0.5000	1/2	0.5000
1/2-27 UNS	0.460	29/64	0.469	0.5000	1/2	0.5000
1/2-28 UNEF	0.461	29/64	0.470	0.5000	1/2	0.5000
1/2-32 UN	0.466	15/32	0.474	0.5000	1/2	0.5000
					12.80mm	0.5039
					13.00mm	0.5118
					33/64	0.5156
					13.20mm	0.5197
					17/32	0.5312
					13.50mm	0.5315
					13.80mm	0.5433
					35/64	0.5469

Standard Series Internal Unified Screw Threads Class 2
Unified Screw Thread	Min Tap Drill Size	Tap Drill	Max Tap Drill Size	Major Diameter	Clearance Drill
					Drill	Size
M14 × 2	11.835mm	12.00mm	12.210mm	14.00mm	14.00mm	0.5512
M14 × 1.5	12.376mm	12.50mm	12.676mm	14.00mm	14.00mm	0.5512
					14.25mm	0.5610
9/16-12 UNC	0.472	31/64	0.490	0.5625	9/16	0.5625
9/16-14 UNS	0.485	31/64	0.501	0.5625	9/16	0.5625
9/16-16 UN	0.495	1/2	0.509	0.5625	9/16	0.5625
9/16-18 UNF	0.502	1/2	0.515	0.5625	9/16	0.5625
9/16-20 UN	0.508	1/2	0.520	0.5625	9/16	0.5625
9/16-24 UNEF	0.517	33/64	0.527	0.5625	9/16	0.5625
9/16-27 UNS	0.522	33/64	0.531	0.5625	9/16	0.5625
9/16-28 UN	0.524	33/64	0.532	0.5625	9/16	0.5625
9/16-32 UN	0.529	17/32	0.536	0.5625	9/16	0.5625
					14.50mm	0.5709
					37/64	0.5781
					14.75mm	0.5807
M15 × 1	13.917mm	14.00mm	14.153mm	15.00mm	15.00mm	0.5906
					19/32	0.5938
					15.25mm	0.6004
					39/64	0.6094
					15.50mm	0.6102
					15.75mm	0.6201

Standard Series Internal Unified Screw Threads Class 2
Unified Screw Thread	Min Tap Drill Size	Tap Drill	Max Tap Drill Size	Major Diameter	Clearance Drill
					Drill	Size
5/8-11 UNC	0.527	17/32	0.546	0.6250	5/8	0.6250
5/8-12 UN	0.535	35/64	0.553	0.6250	5/8	0.6250
5/8-14 UNS	0.548	35/64	0.564	0.6250	5/8	0.6250
5/8-16 UN	0.557	9/16	0.571	0.6250	5/8	0.6250
5/8-18 UNF	0.565	9/16	0.578	0.6250	5/8	0.6250
5/8-20 UN	0.571	9/16	0.582	0.6250	5/8	0.6250
5/8-24 UNEF	0.580	37/64	0.590	0.6250	5/8	0.6250
5/8-27 UNS	0.585	37/64	0.594	0.6250	5/8	0.6250
5/8-28 UN	0.586	37/64	0.595	0.6250	5/8	0.6250
5/8-32 UN	0.591	19/32	0.599	0.6250	5/8	0.6250
M16 × 2	13.835mm	14.00mm	14.210mm	16.00mm	16.00mm	0.6299
M16 × 1.5	14.376mm	14.50mm	14.676mm	16.00mm	16.00mm	0.6299
					16.25mm	0.6398
					41/64	0.6406
					16.50mm	0.6496
					21/32	0.6562
					16.75mm	0.6594
M17 × 1	15.917mm	16.00mm	16.153mm	17.00mm	17.00mm	0.6693
					43/64	0.6719
					17.25mm	0.6791
11/16-12 UN	0.597	39/64	0.615	0.6875	11/16	0.6875
11/16-16 UN	0.620	5/8	0.634	0.6875	11/16	0.6875
11/16-20 UN	0.633	5/8	0.645	0.6875	11/16	0.6875
11/16-24 UNEF	0.642	41/64	0.652	0.6875	11/16	0.6875
11/16-28 UN	0.649	41/64	0.657	0.6875	11/16	0.6875
11/16-32 UN	0.654	21/32	0.661	0.6875	11/16	0.6875
					17.50mm	0.6890
					45/64	0.7031
M18 × 1.5	16.375mm	16.50mm	16.676mm	18.00mm	18.00mm	0.7087

Standard Series Internal Unified Screw Threads Class 2
Unified Screw Thread	Min Tap Drill Size	Tap Drill	Max Tap Drill Size	Major Diameter	Clearance Drill
					Drill	Size
					23/32	0.7188
					18.50mm	0.7283
					47/64	0.7344
					19.00mm	0.7480
3/4-10 UNC	0.642	21/32	0.663	0.7500	3/4	0.7500
3/4-12 UN	0.660	43/64	0.678	0.7500	3/4	0.7500
3/4-14 UNS	0.673	43/64	0.688	0.7500	3/4	0.7500
3/4-16 UNF	0.682	11/16	0.696	0.7500	3/4	0.7500
3/4-18 UNS	0.690	11/16	0.703	0.7500	3/4	0.7500
3/4-20 UNEF	0.696	11/16	0.707	0.7500	3/4	0.7500
3/4-24 UNS	0.705	45/64	0.715	0.7500	3/4	0.7500
3/4-27 UNS	0.710	45/64	0.719	0.7500	3/4	0.7500
3/4-28 UN	0.711	45/64	0.720	0.7500	3/4	0.7500
3/4-32 UN	0.716	23/32	0.724	0.7500	3/4	0.7500
					49/64	0.7656
					19.50mm	0.7677
					25/32	0.7812
M20 × 2.5	17.294mm	17.50mm	17.744mm	20.00mm	20.00mm	0.7874
M20 × 1.5	18.376mm	18.50mm	18.676mm	20.00mm	20.00mm	0.7874
M20 × 1	18.917mm	19.00mm	19.153mm	20.00mm	20.00mm	0.7874
					51/64	0.7969
					20.50mm	0.8071
13/16-12 UN	0.722	23/32	0.740	0.8125	13/16	0.8125
13/16-16 UN	0.745	47/64	0.759	0.8125	13/16	0.8125
13/16-20 UNEF	0.758	3/4	0.770	0.8125	13/16	0.8125
13/16-28 UN	0.774	49/64	0.782	0.8125	13/16	0.8125
13/16-32 UN	0.779	25/32	0.786	0.8125	13/16	0.8125
					21.00mm	0.8268
					53/64	0.8281

Standard Series Internal Unified Screw Threads Class 2
Unified Screw Thread	Min Tap Drill Size	Tap Drill	Max Tap Drill Size	Major Diameter	Clearance Drill
					Drill	Size
					27/32	0.8438
					21.50mm	0.8465
					55/64	0.8594
M22 × 2.5	19.294mm	19.50mm	19.744mm	22.00mm	22.00mm	0.8661
M22 × 1.5	20.376mm	20.50mm	20.676mm	22.00mm	22.00mm	0.8661
7/8-9 UNC	0.755	49/64	0.778	0.8750	7/8	0.8750
7/8-10 UNS	0.767	25/32	0.788	0.8750	7/8	0.8750
7/8-12 UN	0.785	25/32	0.803	0.8750	7/8	0.8750
7/8-14 UNF	0.798	51/64	0.814	0.8750	7/8	0.8750
7/8-16 UN	0.807	13/16	0.821	0.8750	7/8	0.8750
7/8-18 UNS	0.815	13/16	0.828	0.8750	7/8	0.8750
7/8-20 UNEF	0.821	13/16	0.832	0.8750	7/8	0.8750
7/8-24 UNS	0.830	53/64	0.840	0.8750	7/8	0.8750
7/8-27 UNS	0.835	53/64	0.844	0.8750	7/8	0.8750
7/8-28 UN	0.836	53/64	0.845	0.8750	7/8	0.8750
7/8-32 UN	0.841	27/32	0.849	0.8750	7/8	0.8750
					22.50mm	0.8858
					57/64	0.8906
					23.00mm	0.9055
					29/32	0.9062
					59/64	0.9219
					23.50mm	0.9252
15/16-12 UN	0.847	27/32	0.865	0.9375	15/16	0.9375
15/16-16 UN	0.870	7/8	0.884	0.9375	15/16	0.9375
15/16-20 UNEF	0.883	57/64	0.895	0.9375	15/16	0.9375
15/16-28 UN	0.899	57/64	0.907	0.9375	15/16	0.9375
15/16-32 UN	0.904	29/32	0.911	0.9375	15/16	0.9375
M24 × 3	20.752mm	21.00mm	21.252mm	24.00mm	24.00mm	0.9449
M24 × 2	21.835mm	22.00mm	22.210mm	24.00mm	24.00mm	0.9449

Standard Series Internal Unified Screw Threads Class 2
Unified Screw Thread	Min Tap Drill Size	Tap Drill	Max Tap Drill Size	Major Diameter	Clearance Drill
					Drill	Size
					61/64	0.9531
					24.50mm	0.9646
					31/32	0.9688
M24 × 1.5	23.376mm	23.50mm	23.676mm	25.00mm	25.00mm	0.9843
					63/64	0.9844
1-8 UNC	0.865	7/8	0.890	1.0000	1	1.0000
1-10 UNS	0.892	29/32	0.913	1.0000	1	1.0000
1-12 UNF	0.910	59/64	0.928	1.0000	1	1.0000
1-14 UNS	0.923	59/64	0.938	1.0000	1	1.0000
1-16 UN	0.932	15/16	0.946	1.0000	1	1.0000
1-18 UNS	0.940	15/16	0.953	1.0000	1	1.0000
1-20 UNEF	0.946	15/16	0.957	1.0000	1	1.0000
1-24 UNS	0.955	61/64	0.965	1.0000	1	1.0000
1-27 UNS	0.960	61/64	0.969	1.0000	1	1.0000
1-28 UN	0.961	61/64	0.970	1.0000	1	1.0000
1-32 UN	0.966	31/32	0.974	1.0000	1	1.0000
					25.50mm	1.0039
					1 1/64	1.0156
					26.00mm	1.0236
					1 1/32	1.0312
					26.50mm	1.0433
					1 3/64	1.0469
1 1/16-8 UN	0.927	15/16	0.952	1.0625	1 1/16	1.0625
1 1/16-12 UN	0.972	31/32	0.990	1.0625	1 1/16	1.0625
1 1/16-16 UN	0.995	1	1.009	1.0625	1 1/16	1.0625
1 1/16-18 UNEF	1.002	1	1.015	1.0625	1 1/16	1.0625
1 1/16-20 UN	1.008	1	1.020	1.0625	1 1/16	1.0625
1 1/16-28 UN	1.024	1 1/64	1.032	1.0625	1 1/16	1.0625

Standard Series Internal Unified Screw Threads Class 2
Unified Screw Thread	Min Tap Drill Size	Tap Drill	Max Tap Drill Size	Major Diameter	Clearance Drill
					Drill	Size
M27 × 3	23.752mm	24.00mm	24.252mm	27.00mm	27.00mm	1.0630
M27 × 2	24.835mm	25.00mm	25.210mm	27.00mm	27.00mm	1.0630
					1 5/64	1.0781
					27.50mm	1.0827
					1 3/32	1.0938
					28.00mm	1.1024
					1 7/64	1.1094
					28.50mm	1.1220
1 1/8-7 UNC	0.970	63/64	0.998	1.1250	1 1/8	1.1250
1 1/8-8 UN	0.990	1	1.015	1.1250	1 1/8	1.1250
1 1/8-10 UNS	1.017	1 1/64	1.038	1.1250	1 1/8	1.1250
1 1/8-12 UNF	1.035	1 1/32	1.053	1.1250	1 1/8	1.1250
1 1/8-14 UNS	1.048	1 3/64	1.064	1.1250	1 1/8	1.1250
1 1/8-16 UN	1.057	1 1/16	1.071	1.1250	1 1/8	1.1250
1 1/8-18 UNEF	1.065	1 1/16	1.078	1.1250	1 1/8	1.1250
1 1/8-20 UN	1.071	1 1/16	1.082	1.1250	1 1/8	1.1250
1 1/8-24 UNS	1.080	1 5/64	1.090	1.1250	1 1/8	1.1250
1 1/8-28 UN	1.086	1 5/64	1.095	1.1250	1 1/8	1.1250
					1 9/64	1.1406
					29.00mm	1.1417
					1 5/32	1.1562
					29.50mm	1.1614
					1 11/64	1.1719
M30 × 3.5	26.211mm	26.50mm	26.771mm	30.00mm	30.00mm	1.1811
M30 × 2	27.835mm	28.00mm	28.210mm	30.00mm	30.00mm	1.1811
M30 × 1.5	28.376mm	28.50mm	28.676mm	30.00mm	30.00mm	1.1811

Standard Series Internal Unified Screw Threads Class 2
Unified Screw Thread	Min Tap Drill Size	Tap Drill	Max Tap Drill Size	Major Diameter	Clearance Drill
					Drill	Size
1 3/16-8 UN	1.052	1 1/16	1.077	1.1875	1 3/16	1.1875
1 3/16-12 UN	1.097	1 3/32	1.115	1.1875	1 3/16	1.1875
1 3/16-16 UN	1.120	1 1/8	1.134	1.1875	1 3/16	1.1875
1 3/16-18 UNEF	1.127	1 1/8	1.140	1.1875	1 3/16	1.1875
1 3/16-20 UN	1.133	1 1/8	1.145	1.1875	1 3/16	1.1875
1 3/16-28 UN	1.149	1 9/64	1.157	1.1875	1 3/16	1.1875
					30.50mm	1.2008
					1 13/64	1.2031
					1 7/32	1.2188
					31.00mm	1.2205
					1 15/64	1.2344
					31.50mm	1.2402
1 1/4-7 UNC	1.095	1 7/64	1.123	1.2500	1 1/4	1.2500
1 1/4-8 UN	1.115	1 1/8	1.140	1.2500	1 1/4	1.2500
1 1/4-10 UNS	1.142	1 9/64	1.163	1.2500	1 1/4	1.2500
1 1/4-12 UNF	1.160	1 11/64	1.178	1.2500	1 1/4	1.2500
1 1/4-14 UNS	1.173	1 11/64	1.188	1.2500	1 1/4	1.2500
1 1/4-16 UN	1.182	1 3/16	1.196	1.2500	1 1/4	1.2500
1 1/4-18 UNEF	1.190	1 3/16	1.203	1.2500	1 1/4	1.2500
1 1/4-20 UN	1.196	1 3/16	1.207	1.2500	1 1/4	1.2500
1 1/4-24 UNS	1.205	1 13/64	1.215	1.2500	1 1/4	1.2500
1 1/8-28 UN	1.211	1 13/64	1.220	1.2500	1 1/4	1.2500
					32.00mm	1.2598
					32.50mm	1.2795
					1 9/32	1.2812
M33 × 2	30.835mm	31.00mm	31.210mm	33.00mm	33.00mm	1.2992

Standard Series Internal Unified Screw Threads Class 2
Unified Screw Thread	Min Tap Drill Size	Tap Drill	Max Tap Drill Size	Major Diameter	Clearance Drill
					Drill	Size
1 5/16-8 UN	1.177	1 3/16	1.202	1.3125	1 5/16	1.3125
1 5/16-12 UN	1.222	1 15/64	1.240	1.3125	1 5/16	1.3125
1 5/16-16 UN	1.245	1 1/4	1.259	1.3125	1 5/16	1.3125
1 5/16-18 UNEF	1.252	1 1/4	1.265	1.3125	1 5/16	1.3125
1 5/16-20 UN	1.258	1 1/4	1.270	1.3125	1 5/16	1.3125
1 5/16-28 UN	1.274	1 1/4	1.282	1.3125	1 5/16	1.3125
					33.50mm	1.3189
					34.00mm	1.3386
					1 11/32	1.3438
					34.50mm	1.3583
1 3/8-6 UNC	1.195	1 13/64	1.225	1.3750	1 3/8	1.3750
1 3/8-8 UN	1.240	1 1/4	1.265	1.3750	1 3/8	1.3750
1 3/8-10 UNS	1.267	1 9/32	1.288	1.3750	1 3/8	1.3750
1 3/8-12 UNF	1.285	1 9/32	1.303	1.3750	1 3/8	1.3750
1 3/8-14 UNS	1.298	1 9/32	1.314	1.3750	1 3/8	1.3750
1 3/8-16 UN	1.307	1 5/16	1.321	1.3750	1 3/8	1.3750
1 3/8-18 UNEF	1.315	1 5/16	1.328	1.3750	1 3/8	1.3750
1 3/8-20 UN	1.321	1 5/16	1.332	1.3750	1 3/8	1.3750
1 3/8-24 UNS	1.330	1 5/16	1.340	1.3750	1 3/8	1.3750
1 3/8-28 UN	1.336	1 5/16	1.345	1.3750	1 3/8	1.3750
M35 × 1.5	33.376mm	33.50mm	33.676mm	35.00mm	35.00mm	1.3780
					35.50mm	1.3976
					1 13/32	1.4062
M36 × 4	31.670mm	32.00mm	32.270mm	36.00mm	36.00mm	1.4173
M36 × 2	33.835mm	34.00mm	34.210mm	36.00mm	36.00mm	1.4173
					36.50mm	1.4370

Standard Series Internal Unified Screw Threads Class 2
Unified Screw Thread	Min Tap Drill Size	Tap Drill	Max Tap Drill Size	Major Diameter	Clearance Drill
					Drill	Size
1 7/16-6 UN	1.257	1 9/32	1.288	1.4375	1 7/16	1.4375
1 7/16-8 UN	1.302	1 5/16	1.327	1.4375	1 7/16	1.4375
1 7/16-12 UN	1.347	1 11/32	1.365	1.4375	1 7/16	1.4375
1 7/16-16 UN	1.370	1 3/8	1.384	1.4375	1 7/16	1.4375
1 7/16-18 UNEF	1.377	1 3/8	1.390	1.4375	1 7/16	1.4375
1 7/16-20 UN	1.383	1 3/8	1.395	1.4375	1 7/16	1.4375
1 7/16-28 UN	1.399	1 3/8	1.407	1.4375	1 7/16	1.4375
					37.00mm	1.4567
					1 15/32	1.4688
					37.50mm	1.4764
					38.00mm	1.4961
1 1/2-6 UNC	1.320	1 11/32	1.350	1.5000	1 1/2	1.5000
1 1/2-8 UN	1.365	1 3/8	1.390	1.5000	1 1/2	1.5000
1 1/2-10 UNS	1.392	1 13/32	1.413	1.5000	1 1/2	1.5000
1 1/2-12 UNF	1.410	1 27/64	1.428	1.5000	1 1/2	1.5000
1 1/2-14 UNS	1.423	1 27/64	1.438	1.5000	1 1/2	1.5000
1 1/2-16 UN	1.432	1 7/16	1.446	1.5000	1 1/2	1.5000
1 1/2-18 UNEF	1.440	1 7/16	1.452	1.5000	1 1/2	1.5000
1 1/2-20 UN	1.446	1 7/16	1.457	1.5000	1 1/2	1.5000
1 1/2-24 UNS	1.455	1 7/16	1.465	1.5000	1 1/2	1.5000
1 1/2-28 UN	1.461	1 7/16	1.470	1.5000	1 1/2	1.5000
					38.50mm	1.5157
M39 × 2	36.835mm	37.00mm	37.210mm	39.00mm	39.00mm	1.5354
1 9/16-6 UN	1.382	1 13/32	1.413	1.5625	1 9/16	1.5625
1 9/16-8 UN	1.427	1 7/16	1.452	1.5625	1 9/16	1.5625
1 9/16-12 UN	1.472	1 15/32	1.490	1.5625	1 9/16	1.5625
1 9/16-16 UN	1.495	1 1/2	1.509	1.5625	1 9/16	1.5625
1 9/16-18 UNEF	1.502	1 1/2	1.515	1.5625	1 9/16	1.5625
1 9/16-20 UN	1.508	1 1/2	1.520	1.5625	1 9/16	1.5625

Standard Series Internal Unified Screw Threads Class 2
Unified Screw Thread	Min Tap Drill Size	Tap Drill	Max Tap Drill Size	Major Diameter	Clearance Drill
					Drill	Size
M40 × 1.5	38.376mm	38.50mm	38.676mm	40.00mm	40.00mm	1.5748
1 5/8-6 UN	1.445	1 15/32	1.475	1.6250	1 5/8	1.6250
1 5/8-8 UN	1.490	1 1/2	1.515	1.6250	1 5/8	1.6250
1 5/8-10 UNS	1.517	1 1/2	1.538	1.6250	1 5/8	1.6250
1 5/8-12 UN	1.535	1 1/2	1.553	1.6250	1 5/8	1.6250
1 5/8-14 UNS	1.548	1 1/2	1.564	1.6250	1 5/8	1.6250
1 5/8-16 UN	1.557	1 9/16	1.571	1.6250	1 5/8	1.6250
1 5/8-18 UNEF	1.565	1 9/16	1.578	1.6250	1 5/8	1.6250
1 5/8-20 UN	1.571	1 9/16	1.582	1.6250	1 5/8	1.6250
1 5/8-24 UNS	1.580	1 9/16	1.590	1.6250	1 5/8	1.6250
M42 × 4.5	37.129mm	37.50mm	37.799mm	42.00mm	42.00mm	1.6535
M42 × 2	39.835mm	40.00mm	40.210mm	42.00mm	42.00mm	1.6535
1 11/16-6 UN	1.507	1 1/2	1.538	1.6875	1 11/16	1.6875
1 11/16-8 UN	1.552	1 9/16	1.577	1.6875	1 11/16	1.6875
1 11/16-12 UN	1.597	1 9/16	1.615	1.6875	1 11/16	1.6875
1 11/16-16 UN	1.620	1 5/8<