National Coarse		National Fine		National Pipe Tapered		National Pipe Parallel
TAP	DRILL	TAP	DRILL	TAP	DRILL	TAP	DRILL
#1-64	#53	#0-80	3/64"	1/8-27	R	1/8-27	S
#2-56	#51	#1-72	#53	1/4-18	7/16	1/4-18	29/64
#3-48	5/64"	#2-64	#50	3/8-18	37/64	3/8-18	19/32
#4-40	#43	#3-56	#46	1/2-14	23/32	1/2-14	47/64
#5-40	#39	#4-48	#42	3/4-14	59/64	3/4-14	15/16
#6-32	#36	#5-44	#37	1"-11-1/2	1-5/32	1"-11-1/2	1-3/16
#8-32	#29	#6-40	#33	1-1/4-11-1/2	1-1/2	1-1/4-11-1/2	1-33/64
#10-24	#25	#8-36	#29	1-1/2-11-1/2	1-47/64	1-1/2-11-1/2	1-3/4
#12-24	#17	#10-32	#21	2"-11-1/2	2-7/32	2"-11-1/2	2-7/32
1/4-20	#7	#12-28	#15	2-1/2-8	2-5/8	2-1/2-8	2-21/32
5/16-18	F	1/4-28	#3	3"-8	3-1/4	3"-8	3-9/32
3/8-16	5/16	5/16-24	I	3-1/2-8	3-3/4	3-1/2-8	3-25/32
7/16-14	U	3/8-24	Q	4"-8	4-1/4	4"-8	4-9/32
1/2-13	27/64	7/16-20	W
9/16-12	31/64	1/2-20	29/64
5/8-11	17/32	9/16-18	33/64
3/4-10	21/32	5/8-18	37/64
7/8-9	49/64	3/4-16	11/16
1"-8	7/8	7/8-14	13/16
1-1/8-7	63/64	1"-14	15/16
1-1/4-7	1-7/64	1-1/8-12	1-3/64
1-1/2-6	1-11/32	1-1/4-12	1-11/64
1-3/4-5	1-35/64	1-1/2-12	1-27/64
2"-4-1/2	1-25/32	1-3/4-12	1-43/64
		2"-12	1-59/64