Threaded Insert Torque

Traditional material dial tables, manufactured from either aluminum or steel, have tooling attachment holes drilled and tapped into the dial surface. Of particular interest is the pull out performance of threaded inserts in the carbon dial table compared to drilled and tapped holes in traditional dial tables.

Tooling attachment is usually accomplished using steel socket head cap screws with a tensile strength of 190,000 psi minimum.

Before looking at the pull out performance of a threaded insert and comparing it with the pull out performance of threaded holes in aluminum and steel dial tables, it is informative to look at the screw first, with respect to diameter, threads per inch (Unified Course [UNRC]Unified Fine [UNRF]), thread length, tensile strength, and recommended seating torque (based on 100,000 psi Tensile Stress in the Screw, REF Unbrako Screw Data Guide).

Bolt analysis performed using FUTEK screw torque calculations, Aluminum Mic6 yield 15,000 psi, k=2.

Screw Size Screw Dia. (inch) Engaged Length (Inches) UNRC Tension Resultant (lbs) UNRF Tension Resultant (lbs) UNRC Max Torque (in-lb) UNRF Max Torque (in-lb) 32 40 .75 1,730 1,930 28 32 32 36 .875 2,660 2,800 49 50 24 32 .875 3,330 3,800 64 76 20 28 1.000 6,050 6,910 150 170 18 24 1.125 9,960 11,000 305 325 16 24 1.25 14,700 17,700 545 570 13 20 1.5 27,000 30,400 1,300 1,370 Screw sizes are those usually encountered in the automation assembly industry for attachment of tooling.

Bolt analysis performed using FUTEK screw torque calculations, Aluminum 6061-T6 yield 40,000 psi, k=2.

Screw Size Screw Dia. (inch) Engaged Length (Inches) UNRC Tension Resultant (lbs) UNRF Tension Resultant (lbs) UNRC Max Torque (in-lb) UNRF Max Torque (in-lb) 6 .138 .207 625 709 17.3 19.6 8 .164 .246 992 1,046 32.6 34.3 10 .190 .285 1,243 1,439 47.3 54.7 1/4 .250 .375 2,322 2,669 116 133 5/16 .312 .468 3,903 4,322 244 270 3/8 .375 .563 5,842 6,576 438 493 1/2 .500 .750 10,879 12,138 1,087 1,213 Screw sizes are those usually encountered in the automation assembly industry for attachment of tooling.

Bolt analysis performed using FUTEK screw torque calculations, A36 steel yield 36,000 psi, k=2.

Screw Size Screw Dia. (inch) Engaged Length (Inches) UNRC Tension Resultant (lbs) UNRF Tension Resultant (lbs) UNRC Max Torque (in-lb) UNRF Max Torque (in-lb) 6 .138 .207 562 638 15.5 17.6 8 .164 .246 893 942 29.3 30.9 10 .190 .285 1,119 1,294 42.5 49.2 1/4 .250 .375 2,089 2,402 104 120 5/16 .312 .468 3,513 3,890 219 243 3/8 .375 .563 5,258 5,919 394 443 1/2 .500 .750 9,792 10,924 979 1,092 Screw sizes are those usually encountered in the automation assembly industry for attachment of tooling.