RF Cafe - Numbered Drill Sizes

Drill Sizes - Numbered

Drill bits are available in a number of sizes, and the size designations include letters, numbers, decimals, and fractions. Decimal drill sizes further include both SAE units and metric units. This particular page presents the numbered drill size series. RF Cafe also has drill size tables for lettered drill size varieties.

These drill bits are almost always of the twist type that advance through the material being bored by turning in a clockwise direction as viewed from the top. They are said to be right-hand drill bits.

#	Diameter (in)	#	Diameter (in)	#	Diameter (in)	#	Diameter (in)	#	Diameter (in)
1	0.2280	21	0.1590	41	0.0960	61	0.0390	81	.0130
2	0.2210	22	0.1570	42	0.0935	62	0.0380	82	.0125
3	0.2130	23	0.1540	43	0.0890	63	0.0370	83	.0120
4	0.2090	24	0.1520	44	0.0860	64	0.0360	84	.0115
5	0.2055	25	0.1495	45	0.0820	65	0.0350	85	.0110
6	0.2040	26	0.1470	46	0.0810	66	0.0330	86	.0105
7	0.2010	27	0.1440	47	0.0785	67	0.0320	87	.0100
8	0.1990	28	0.1405	48	0.0760	68	0.0310	88	.0095
9	0.1960	29	0.1360	49	0.0730	69	0.0292	89	.0091
10	0.1935	30	0.1285	50	0.0700	70	0.0280	90	.0087
11	0.1910	31	0.1200	51	0.0670	71	0.0260	91	.0083
12	0.1890	32	0.1160	52	0.0635	72	0.0250	92	.0079
13	0.1850	33	0.1130	53	0.0595	73	0.0240	93	.0075
14	0.1820	34	0.1110	54	0.0550	74	0.0225	94	.0071
15	0.1800	35	0.1100	55	0.0520	75	0.0210	95	.0067
16	0.1770	36	0.1065	56	0.0465	76	0.0200	96	.0063
17	0.1730	37	0.1040	57	0.0430	77	0.0180	97	.0059
18	0.1695	38	0.1015	58	0.0420	78	0.0160
19	0.1660	39	0.0995	59	0.0410	79	0.0145
20	0.1610	40	0.0980	60	0.0400	80	0.0135

Thanks to Jeff M. for pointing out the previous error in the #61 - #80 values (they were shifted by one row).