Free Downloadable Tap Drill Chart – Centimeters and Inches

For those of you looking for some of the basics on tap and drill, size and threads, how to use a drill and tap chart and drill bits, we’ll answer some questions below on this page.

Inch	Metric	Drill Size	Dec. Eq./ Inches	CM	Drill Size	Dec. Eq/ Inches	CM	Closest Fractional	Inch	mm	Inch	mm	Drill Size	Dec. Eq.	Drill Size	Dec. Eq.
0-80		3/64	0.0469	0.1191	54	0.055	0.1397	3/64″	0.073	1.8542	0.067	1.7018	3/64	0.0469	55	0.052
	M1.6 X 0.35	1.25MM	0.0492	0.1250	1.45MM	0.0571	0.1450
	M1.8 X 0.35	1.45MM	0.0571	0.1450	1.65MM	0.065	0.1651
1-64		53	0.0595	0.1511	51	0.067	0.1702		0.089	2.2606	0.081	2.0574	53	0.0595	1/16	0.0625
1-72		53	0.0595	0.1511	51	0.067	0.1702	1/16″	0.089	2.2606	0.081	2.0574	53	0.0595	52	0.0635
	M2 X 0.40	1.60MM	0.063	0.1600	1.80MM	0.0709	0.1801
2-56		50	0.07	0.1778	5/64	0.0781	0.1984		0.106	2.6924	0.094	2.3876	50	0.07	49	0.073
2-64		50	0.07	0.1778	47	0.0785	0.1994		0.106	2.6924	0.094	2.3876	50	0.07	48	0.076
	M2.2 X 0.45	1.75MM	0.0689	0.1750	2.00MM	0.0787	0.1999
	M2.5 X 0.45	2.05MM	0.0807	0.2050	2.30MM	0.0906	0.2301
3-48		47	0.0785	0.1994	43	0.089	0.2261	5/64″	0.12	3.048	0.106	2.6924	47	0.0785	44	0.086
3-56		46	0.081	0.2057	2.3	0.0905	0.2299		0.12	3.048	0.106	2.6924	45	0.082	43	0.089
4-40		43	0.089	0.2261	38	0.1015	0.2578	3/32″	0.136	3.4544	0.125	3.175	43	0.089	41	0.096
4-48		42	0.0935	0.2375	2.6	0.1024	0.2601	3/32″	0.136	3.4544	0.125	3.175	42	0.0935	40	0.098
	M3 X 0.50	2.50MM	0.0984	0.2499	7/64	0.1094	0.2779
5-40		38	0.1015	0.2578	33	0.113	0.2870		0.154	3.9116	0.141	3.5814	38	0.1015	7/64	0.1094
5-44		37	0.104	0.2642	2.9	0.1142	0.2901		0.154	3.9116	0.141	3.5814	37	0.104	35	0.11
	M3 X 0.60	2.90MM	0.1142	0.2901	3.20MM	0.126	0.3200
6-32		36	0.1065	0.2705	1/8	0.125	0.3175	7/64″	0.17	4.318	0.154	3.9116	36	0.1065	32	0.116
6-40		33	0.113	0.2870	3.25	0.128	0.3251		0.17	4.318	0.154	3.9116	33	0.113	31	0.12
	M4 X 0.70	3.30MM	0.1299	0.3299	3.70MM	0.1476	0.3749
8-32		29	0.136	0.3454	25	0.1495	0.3797		0.194	4.9276	0.18	4.572	29	0.136	27	0.144
8-36		29	0.136	0.3454	24	0.152	0.3861	9/64″	0.194	4.9276	0.18	4.572	29	0.136	26	0.147
	M4.5 X 0.75	3.70MM	0.1476	0.3749	4.10MM	0.1614	0.4100
10-24		26	0.147	0.3734	11/64	0.1719	0.4366	5/32″	0.221	5.6134	0.206	5.2324	25	0.1495	20	0.161
10-32		21	0.159	0.4039	16	0.177	0.4496	5/32″	0.221	5.6134	0.206	5.2324	21	0.159	18	0.1695
	M5 X 0.75	4.20MM	0.1654	0.4201
12-24		16	0.177	0.4496	8	0.199	0.5055	11/64″					16	0.177	12	0.189
12-28		15	0.18	0.4572	7	0.201	0.5105	3/16″					14	0.182	10	0.1935
	M6 X 1.00	5.00MM	0.1969	0.5001	7/32	0.2188	0.5558
1/4-20		7	0.201	0.5105	1	0.228	0.5791	13/64″	0.281	7.1374	0.266	6.7564	7	0.201	7/32	0.2188
1/4-28		3	0.213	0.5410	15/64	0.234	0.5944	7/32″	0.281	7.1374	0.266	6.7564	3	0.213	1	0.228
	M7 X 1.00	6.00MM	0.2362	0.5999	F	0.257	0.6528
5/16-18		F	0.257	0.6528	L	0.29	0.7366	17/64″	0.344	8.7376	0.328	8.3312	F	0.257	J	0.277
5/16-24		I	0.272	0.6909	M	0.295	0.7493		0.344	8.7376	0.328	8.3312	I	0.272	9/32	0.2812
	M8 X 1.25	6.70MM	0.2638	0.6701	7/40	0.2913	0.7399
	M8 X 1.0	7.00MM	0.2756	0.7000	19/64	0.2969	0.7541
3/8-16		5/16	0.3125	0.7938	S	0.348	0.8839	5/16″	0.406	10.3124	0.391	9.9314	5/16	0.3125	Q	0.332
3/8-24		Q	0.332	0.8433	T	0.358	0.9093	21/64″	0.406	10.3124	0.391	9.9314	Q	0.332	S	0.348
	M10 X 1.50	8.50MM	0.3346	0.8499	U	0.368	0.9347
	M10 X 1.25	8.70MM	0.3425	0.8700	9.4	0.3701	0.9401
7/16-14		U	0.368	0.9347	Y	0.404	1.0262	23/64″					U	0.368	25/64	0.3906
7/16-20		25/64	0.3906	0.9921	Z	0.413	1.0490	25/64″					25/64	0.3906	13/32	0.4062
	M12 X 1.75	10.20MM	0.4016	1.0201	11.2	0.4409	1.1199
	M12 X 1.25	10.80MM	0.4252	1.0800	11.5	0.4528	1.1501
1/2-13		27/64	0.4219	1.0716	15/32	0.4682	1.1892	27/64″	0.531	13.4874	0.516	13.1064	27/64	0.4219	29/64	0.4531
1/2-13		29/64	0.4531	1.1509	12.25	0.4823	1.2250	29/64″	0.531	13.4874	0.516	13.1064	29/64	0.4531	15/32	0.4688
	M14 X 2.00	12.00MM	0.4224	1.0729	33/64	0.5156	1.3096
9/16-12		31/64	0.4844	1.2304	17/32	0.5312	1.3492	31/64″					31/64	0.4844	33/64	0.5156
9/16-18		33/64	0.5156	1.3096	13.5	0.5315	1.3500	33/64″					33/64	0.5156	17/32	0.5312
5/8-11		17/32	0.5312	1.3492	14.75	0.5807	1.4750	17/32″					17/32	0.5312	9/16	0.5625
5/8-18		37/64	0.5781	1.4684	15.25	0.6004	1.5250	37/64″					37/64	0.5781	19/32	0.5938
	M16 X 2.00	14.00MM	0.5512	1.4000	19/32	0.5938	1.5083
	M16 X 1.50	14.50MM	0.5906	1.5001	15.25	0.6004	1.5250
	M18 X 2.50	15.50MM	0.6102	1.5499	39/64	0.6094	1.5479
	M18 X 1.50	16.50MM	0.6496	1.6500	17.25	0.6791	1.7249
3/4-10		21/32	0.6562	1.6667	45/64	0.7031	1.7859	21/32″					21/32	0.6562	11/16	0.6875
3/4-16		11/16	0.6875	1.7463	23/32	0.7188	1.8258	11/16″					11/16	0.6875	45/64	0.7031
	M20 X 2.50	17.50MM	0.689	1.7501
	M20 X 1.50	18.50MM	0.7283	1.8499
	M22 X 2.50	19.50MM	0.7677	1.9500
	M22 X 1.50	20.50MM	0.8071	2.0500
7/8-9		49/64	0.7656	1.9446				49/64″					49/64	0.7656	51/64	0.7969
7/8-14		13/16	0.8125	2.0638				13/16″					13/16	0.8125	53/64	0.8281
	M24 X 3.00	21.00MM	0.8268	2.1001
	M24 X 2.00	22.00MM	0.8661	2.1999
1-8		7/8	0.875	2.2225				7/8″					7/8	0.875	59/64	0.9219
1-12		59/64	0.9219	2.3416				59/64″					15/16	0.9375	61/64	0.9531
	M27 X 3.00	24.00MM	0.9449	2.4000
	M27 X 2.00	25.00MM	0.9843	2.5001
1-1/8-7		63/64	0.9844	2.5004				63/64″
1-1/8-12		1-3/64	1.0469	2.6591				1 3/64″
	M30 X 3.50	26.50MM	1.0433	2.6500
	M30 X 2.00	28.00MM	1.1024	2.8001
1-1/4-7		1-7/64	1.1094	2.8179				1 7/64″
1-1/4-12		1-11/64	1.1719	2.9766				1 11/64″
	M33 X 3.50	29.50MM	1.1614	2.9500
	M33 X 2.00	31.00MM	1.2205	3.1001
1-3/8-6		1-7/32	1.2188	3.0958				1 7/32″
1-3/8-12		1-19/64	1.2969	3.2941				1 19/64″
	M36 X 4.00	32.00MM	1.2598	3.1999
	M36 X 3.00	33.00MM	1.2992	3.3000
1-1/2-6		1-11/32	1.3438	3.4133				1 11/32″
1-1/2-12		1-27/64	1.4219	3.6116				1 27/64″
	M39 X 4.00	35.00MM	1.378	3.5001
	M39 X 3.00	36.00MM	1.4173	3.5999

HOW DO I KNOW WHAT SIZE DRILL TO TAP?

For Metric threads, you can calculate the tapping drill by subtracting the pitch from the diameter of the thread. 

Here is an example, for an M5x0. 75 thread the tapping drill is 5-0.75mm = 4.25mm. For Imperial (inch) threads the tapping drill size is calculated in the same way, diameter minus pitch.

HOW TO READ A TAP DRILL CHART?

Reading a tap drill chart is simple, taking our tap drill size chart as an example, simply scroll through the left-hand column and find the tap drill size you need, on the right you’ll find a column with the drill bit you need. You can find a drill and tap chart pdf here; it’s a completely free printable tap drill chart that we hope can help you in your operations.

You might be interested in: DFM Electronics Guidelines 

HOW TO USE A TAP DRILL CHART?

The best thing to do is find a tap drill clearance chart you can print, just like the one we offer in this article and print it for your lab so your team can easily access it. A drill size chart contains drill sizes and thread data that is so large that is almost impossible for a mechanical engineer to remember it all.

The proliferation of fittings and connectors makes correct thread identification a difficult and exhausting task even for the most experienced technician or mechanical engineers; there’s always a new thread out there. While there are common threads like the American pipe thread, the unified thread; there are many unfamiliar threads.

When it comes to drill bit sizes, there at least 153, those are the ones I can recall right now, there could be more, hence the need for a drill size chart with thread information.

WHAT IS A DRILL BIT AND THREAD?

A drill bit is a cutting tool which purpose is to remove material to create a hole, it will most likely always be a cross section circular shape. Drill Bits come in many sizes and shapes. The thread or threading on the sides of the hole is needed to hold the screws or bolts in place.