Tap Size		Decimal size		Cutting Tap			Cold Forming Tap
in	mm	in	mm	55%	60%	70%	55%	60%	75%
#0-80		0.060	1.52	.051in	.050in	.049in	.055in	.055in	.054in
	M1.6x0.35	0.063	1.60	1.35mm	1.33mm	1.26mm	1.47mm	1.46mm	1.42mm
	M1.8x0.35	0.071	1.80	1.55mm	1.53mm	1.46mm	1.67mm	1.66mm	1.62mm
#1-64		0.073	1.85	.062in	.061in	.059in	.067in	.067in	.065in
#1-72		0.073	1.85	.063in	.062in	.060in	.068in	.067in	.066in
	M2x0.4	0.079	2.00	1.71mm	1.69mm	1.61mm	1.85mm	1.84mm	1.80mm
#2-56		0.086	2.18	.073in	.072in	.070in	.079in	.079in	.077in
#2-64		0.086	2.18	.075in	.074in	.072in	.080in	.080in	.078in
	M2.2x0.45	0.087	2.20	1.88mm	1.85mm	1.76mm	2.03mm	2.02mm	1.97mm
	M2.5x0.45	0.098	2.50	2.18mm	2.15mm	2.06mm	2.33mm	2.32mm	2.27mm
#3-48		0.099	2.51	.084in	.083in	.080in	.091in	.091in	.088in
#3-56		0.099	2.51	.086in	.085in	.083in	.092in	.092in	.090in
#4-40		0.112	2.84	.094in	.093in	.089in	.103in	.102in	.099in
#4-48		0.112	2.84	.097in	.096in	.093in	.104in	.104in	.101in
	M3x0.5	0.118	3.00	2.64mm	2.61mm	2.51mm	2.81mm	2.80mm	2.75mm
	M3x.035	0.118	3.00	2.97mm	2.97mm	2.97mm	2.99mm	2.99mm	2.98mm
#5-40		0.125	3.18	.107in	.106in	.102in	.116in	.115in	.112in
#5-44		0.125	3.18	.109in	.107in	.104in	.117in	.116in	.113in
	M3.5x0.6	0.138	3.50	3.07mm	3.03mm	2.92mm	3.28mm	3.26mm	3.19mm
	M3.5x0.35	0.138	3.50	3.25mm	3.23mm	3.16mm	3.37mm	3.36mm	3.32mm
#6-32		0.138	3.51	.116in	.114in	.110in	.126in	.125in	.122in
#6-40		0.138	3.51	.120in	.119in	.115in	.129in	.128in	.125in
	M4x0.7	0.157	4.00	3.50mm	3.45mm	3.32mm	3.74mm	3.71mm	3.64mm
	M4x0.5	0.157	4.00	3.64mm	3.61mm	3.51mm	3.81mm	3.80mm	3.75mm
#8-32		0.164	4.17	.142in	.140in	.136in	.152in	.151in	.148in
#8-36		0.164	4.17	.144in	.142in	.139in	.154in	.153in	.150in
	M4.5x0.75	0.177	4.50	3.96mm	3.92mm	3.77mm	4.22mm	4.19mm	4.12mm
	M4.5x0.50	0.177	4.50	4.14mm	4.11mm	4.01mm	4.31mm	4.30mm	4.25mm
#10-24		0.190	4.83	.160in	.158in	.152in	.174in	.173in	.169in
#10-32		0.190	4.83	.168in	.166in	.162in	.178in	.177in	.174in
	M5x0.80	0.197	5.00	4.43mm	4.38mm	4.22mm	4.70mm	4.67mm	4.59mm
	M5x0.50	0.197	5.00	4.64mm	4.61mm	4.51mm	4.81mm	4.80mm	4.75mm
#12-24		0.216	5.49	.186in	.184in	.178in	.200in	.199in	.195in
#12-28		0.216	5.49	.190in	.188in	.184in	.203in	.201in	.198in
	M6x1.0	0.236	6.00	5.29mm	5.22mm	5.03mm	5.63mm	5.59mm	5.49mm
	M6x0.75	0.236	6.00	5.46mm	5.42mm	5.27mm	5.72mm	5.69mm	5.62mm
1/4-20		0.250	6.35	.214in	.211in	.205in	.231in	.230in	.225in
1/4-28		0.250	6.35	.224in	.222in	.218in	.237in	.235in	.232in
	M7x1.0	0.276	7.00	6.29mm	6.22mm	6.03mm	6.63mm	6.59mm	6.49mm
	M7x0.75	0.276	7.00	6.46mm	6.42mm	6.27mm	6.72mm	6.69mm	6.62mm
5/16-18		0.313	7.94	.273in	.269in	.262in	.292in	.290in	.284in
5/16-24		0.313	7.94	.283in	.280in	.275in	.297in	.296in	.291in
	M8x1.25	0.315	8.00	7.11mm	7.03mm	6.78mm	7.53mm	7.49mm	7.36mm
	M8x1.0	0.315	8.00	7.29mm	7.22mm	7.03mm	7.63mm	7.59mm	7.49mm
3/8-16		0.375	9.53	.330in	.326in	.318in	.352in	.350in	.343in
3/8-24		0.375	9.53	.345in	.343in	.337in	.359in	.358in	.354in
	M10x1.5	0.394	10.00	8.93mm	8.83mm	8.54mm	9.44mm	9.39mm	9.24mm
	M10x1.25	0.394	10.00	9.11mm	9.03mm	8.78mm	9.53mm	9.49mm	9.36mm
	M10x1.0	0.394	10.00	9.29mm	9.22mm	9.03mm	9.63mm	9.59mm	9.49mm
7/16-14		0.438	11.11	.386in	.382in	.373in	.411in	.408in	.401in
7/16-20		0.438	11.11	.402in	.399in	.392in	.419in	.417in	.412in
	M12x1.75	0.472	12.00	10.75mm	10.64mm	10.30mm	11.35mm	11.29mm	11.11mm
	M12x1.5	0.472	12.00	10.93mm	10.83mm	10.54mm	11.44mm	11.39mm	11.24mm
	M12x1.0	0.472	12.00	11.29mm	11.22mm	11.03mm	11.63mm	11.59mm	11.49mm
1/2-13		0.500	12.70	.445in	.440in	.430in	.471in	.469in	.461in
1/2-20		0.500	12.70	.464in	.461in	.455in	.481in	.480in	.475in
	M14x2.0	0.551	14.00	12.57mm	12.44mm	12.05mm	13.25mm	13.18mm	12.98mm
	M14x1.5	0.551	14.00	12.93mm	12.83mm	12.54mm	13.44mm	13.39mm	13.24mm
9/16-12		0.563	14.29	.503in	.498in	.487in	.531in	.529in	.520in
9/16-18		0.563	14.29	.523in	.519in	.512in	.542in	.540in	.534in
5/8-11		0.625	15.88	.560in	.554in	.542in	.591in	.588in	.579in
5/8-18		0.625	15.88	.585in	.582in	.574in	.604in	.602in	.597in
	M16x2.0	0.630	16.00	14.57mm	14.44mm	14.05mm	15.25mm	15.18mm	14.98mm
	M16x1.5	0.630	16.00	14.93mm	14.83mm	14.54mm	15.44mm	15.39mm	15.24mm
	M18x2.5	0.709	18.00	16.21mm	16.05mm	15.56mm	17.07mm	16.98mm	16.73mm
	M18x1.5	0.709	18.00	16.93mm	16.83mm	16.54mm	17.44mm	17.39mm	17.24mm
3/4-10		0.750	19.05	.679in	.672in	.659in	.713in	.709in	.699in
3/4-16		0.750	19.05	.705in	.701in	.693in	.727in	.725in	.718in
	M20x2.5	0.787	20.00	18.21mm	18.05mm	17.56mm	19.07mm	18.98mm	18.73mm
	M20x1.5	0.787	20.00	18.93mm	18.83mm	18.54mm	19.44mm	19.39mm	19.24mm
	M22x2.5	0.866	22.00	20.21mm	20.05mm	19.56mm	21.07mm	20.98mm	20.73mm
	M22x1.5	0.866	22.00	20.93mm	20.83mm	20.54mm	21.44mm	21.39mm	21.24mm
7/8-9		0.875	22.23	.796in	.788in	.774in	.833in	.830in	.818in
7/8-14		0.875	22.23	.824in	.819in	.810in	.848in	.846in	.839in
	M24x3.0	0.945	24.00	21.86mm	21.66mm	21.08mm	22.88mm	22.78mm	22.47mm
	M24x2.0	0.945	24.00	22.57mm	22.44mm	22.05mm	23.25mm	23.18mm	22.98mm
1-8		1.000	25.40	.911in	.903in	.886in	.953in	.949in	.936in
1-12		1.000	25.40	.940in	.935in	.924in	.969in	.966in	.958in

Last Updated: 20 February 2015