TORX screw head size designations use the capital letter "T", followed by a number. A smaller number corresponds to a smaller point-to-point dimension of the screw head. Common sizes include T4, T5, T6, T7, T8, T9, T10 and T15 although they can be as high as T100. Each screw size requires the properly-sized screwdriver. In the table below 1 Nm = 8.851 lbf-in.

 

Dimensional & Torque Specifications
of TORX Screwdrivers for use with Internal
Socket Head Type TORX Screws

 

 

Point to Point Dimensions
Size Inch
P to P		 Metric
P to P		 Maximum Torque
Range
T1 .031 .81mm .02 to .03 N m
T2 .036 .93mm .07 to .09 N m
T3 .046 1.10mm .14 to .18 N m
T4 .050 1.28mm .22 to .28 N m
T5 .055" 1.42 mm .43 to .51 N m
T6 .066" 1.70 mm .75 to .9 N m
T7 .078" 1.99 mm 1.4 to 1.7 N m
T8 .090" 2.31 mm 2.2 to 2.6 N m
T9 .098" 2.50 mm 2.8 to 3.4 N m
T10 .107" 2.74 mm 3.7 to 4.5 N m
T15 .128" 3.27 mm 6.4 to 7.7 N m
T20 .151" 3.86 mm 10.5 to 12.7 N m
T25 .173" 4.43 mm 15.9 to 19 N m
T27 .195" 4.99 mm 22.5 to 26.9 N m
T30 .216" 5.52 mm 31.1 to 37.4 N m
T40 .260" 6.65 mm 54.1 to 65.1 N m
T45 .306" 7.82 mm 86 to 103.2 N m
T50 .346" 8.83 mm 132 to 158 N m
T55 .440" 11.22 mm 218 to 256 N m
T60 .519 13.25 mm 379 to 445 N m
T70 .610 15.51 mm 630 t0 700 N m
T80 .690 17.54 mm 943 to 1048 N m
T90 .784 19.92 mm 1334 to 1483 N m
T100 .871 22.13 mm 1843 to 2048 N m