Ohio Drill and Tool Company Standard Taps

Common Machine Screw Sizes And Common Fractional Sizes

Common Fractional Sizes N.C. & N.F. Series
catalog page: 50
Nominal Tap Sizes	Bottom Tap Part Number	Tap-Drill To Produce Approx. 75% Full Thread
7/8 - 9	316161	3/4
1/4 - 20	319001	7
1/4 - 28	319011	3
5/16 - 18	319021	F
5/16 - 24	319031	I
3/8 - 16	319041	5/16
3/8 - 24	319051	Q
7/16 - 14	319061	U
7/16 - 20	319071	25/64
1/2 - 13	319081	27/64
1/2 - 20	319091	29/64
9/16 - 12	319101	31/64
9/16 - 18	319111	33/64
5/8 - 11	319121	17/32
5/8 - 18	319131	37/64
3/4 - 10	319141	21/32
3/4 - 16	319151	11/16
7/8 - 14	319171	13/16
1 - 8	319181	7/8
1 - 12	319191	15/16
1 - 14	319194	15/16
1-1/8 - 7	319201	63/64
1-1/8 - 12	319211	1-3/64
1-1/4 - 7	319221	1-7/64
1-1/4 - 12	319231	1-11/64
Common Fractional Sizes N.C. & N.F. Series
catalog page: 50
Nominal Tap Sizes	Plug Tap Part Number	Tap-Drill To Produce Approx. 75% Full Thread
1/4 - 20	319002	7
1/4 - 28	319012	3
5/16 - 18	319022	F
5/16 - 24	319032	I
3/8 - 16	319042	5/16
3/8 - 24	319052	Q
7/16 - 14	319062	U
7/16 - 20	319072	25/64
1/2 - 13	319082	27/64
1/2 - 20	319092	29/64
9/16 - 12	319102	31/64
9/16 - 18	319112	33/64
5/8 - 11	319122	17/32
5/8 - 18	319132	37/64
3/4 - 10	319142	21/32
3/4 - 16	319152	11/16
7/8 - 9	319162	3/4
7/8 - 14	319172	13/16
1 - 8	319182	7/8
1 - 12	319192	15/16
1 - 14	319195	15/16
1-1/8 - 7	319202	63/64
1-1/8 - 12	319212	1-3/64
1-1/4 - 7	319222	1-7/64
1-1/4 - 12	319232	1-11/64
Common Fractional Sizes N.C. & N.F. Series
catalog page: 50
Nominal Tap Sizes	Taper Tap Part Number	Tap-Drill To Produce Approx. 75% Full Thread
1/4 - 20	319003	7
1/4 - 28	319013	3
5/16 - 18	319023	F
5/16 - 24	319033	I
3/8 - 16	319043	5/16
3/8 - 24	319053	Q
7/16 - 14	319063	U
7/16 - 20	319073	25/64
1/2 - 13	319083	27/64
1/2 - 20	319093	29/64
9/16 - 12	319103	31/64
9/16 - 18	319113	33/64
5/8 - 11	319123	17/32
5/8 - 18	319133	37/64
3/4 - 10	319143	21/32
3/4 - 16	319153	11/16
7/8 - 9	319163	3/4
7/8 - 14	319173	13/16
1 - 8	319183	7/8
1 - 12	319193	15/16
1 - 14	319196	15/16
1-1/8 - 7	319203	63/64
1-1/8 - 12	319213	1-3/64
1-1/4 - 7	319223	1-7/64
1-1/4 - 12	319233	1-11/64
Common Machine Screw Sizes Tap Drill & Body Clearance
catalog page: 50
Nominal Tap Sizes	Bottom Tap Part Number	Tap-Drill To Produce Approx. 75% Full Thread
4 - 40	318071	43
4 - 48	318081	42
5 - 40	318091	38
5 - 44	318101	37
6 - 32	318111	36
6 - 40	318121	33
8 - 32	318131	29
8 - 36	318141	29
10 - 24	318151	25
10 - 32	318161	21
12 - 24	318171	16
12 - 28	318181	14
Common Machine Screw Sizes Tap Drill & Body Clearance
catalog page: 50
Nominal Tap Sizes	Plug Tap Part Number	Tap-Drill To Produce Approx. 75% Full Thread
4 - 40	318072	43
4 - 48	318082	42
5 - 40	318092	38
5 - 44	318102	37
6 - 32	318112	36
6 - 40	318122	33
8 - 32	318132	29
8 - 36	318142	29
10 - 24	318152	25
10 - 32	318162	21
12 - 24	318172	16
12 - 28	318182	14
Common Machine Screw Sizes Tap Drill & Body Clearance
catalog page: 50
Nominal Tap Sizes	Taper Tap Part Number	Tap-Drill To Produce Approx. 75% Full Thread
4 - 40	318073	43
4 - 48	318083	42
5 - 40	318093	38
5 - 44	318103	37
6 - 32	318113	36
6 - 40	318123	33
8 - 32	318133	29
8 - 36	318143	29
10 - 24	318153	25
10 - 32	318163	21
12 - 24	318173	16
12 - 28	318183	14