These values are recommendations,
functionality has precedence.
Screw
Size
Decimal
Diameter
Close Fit Normal Fit Loose Fit
#0000 .021" .024" .026" .028"
#000 .034" .037" .041" .043"
#00 .047" .052" .055" .0595"
#0 .060" .0635" .070" .073"
#1 .073" .076" .081" .089"
#2 .086" .089" .096" .1065"
#3 .099" .104" .110" .120"
#4 .112" .116" .1285" .136"
#5 .125" .1285" .136" .154"
#6 .138" .144" .1495" .1695"
#8 .164" .1695 .177 .1935
#10 .190" .196" .201" .221"
#12 .216" .221" .228" .246"
1/4" .250" .257" .266" .2812"
5/16" .3125" .323" .332" .3437"
3/8" .375" .386" .397" .4062"
7/16" .4375" .4531" .4687" .4844"
1/2" .500" .5156" .5312" .5469"
9/16" .5625" .5781" .5937" .6094"
5/8" .625" .6406" .6562" .6719"
3/4" .750" .7656" .7812" .7969"
7/8" .875" .8906" .9062" .9219"
1" 1.000" 1.0156" 1.0312" 1.0469"
1-1/8" 1.125" 1.1406" 1.1562" 1.1719"
1-1/4" 1.250" 1.2656" 1.2812" 1.2969"
1-3/8" 1.375" 1.3906" 1.4062" 1.4219"
1-1/2" 1.500" 1.5156" 1.5312" 1.5469"
1-3/4" 1.750" 1.7656" 1.7812" 1.7969"
2" 2.000" 2.0156" 2.0312" 2.0469"
2-1/4" 2.250" 2.2656" 2.2812" 2.2969"
2-1/2" 2.500" 2.5156" 2.5312" 2.5469"
2-3/4" 2.750" 2.7656" 2.7812" 2.7969"
3" 3.000" 3.0156" 3.0312" 3.0469"
3-1/4" 3.250" 3.2656" 3.2812" 3.2969"
3-1/2" 3.500" 3.5156" 3.5312" 3.5469"
3-3/4" 3.750" 3.7656" 3.7812" 3.7969"
4" 4.000" 4.0156" 4.0312" 4.0469"
Theoretical Machinist Website

Last Updated: 02 July 2020