Thread Rolling Self-Tapping Screw
Product Introduction
Thread Rolling Self-Tapping Screw
Trilobular thread rolling screw. As each lobe of the screw moves through the pilot hole in the nut material, it forms and work-hardens the nut thread metal, producing an uninterrupted grain flow.
Applications/Advantages:
For drilled, punched or cored holes in all ductlle metals and punch extruded metals. Eliminates chips, requires low drive torque and provides excellent resistance to vibrational loosening.

THREAD ROLLING SCREWS | |||||
Nominal Screw Length | C | D | G | ||
Screw Body Dimensions | Point | ||||
Diameter of Circumscribing Circle | Measurement Acrose Center | Diameter of Circumscribing Circle | |||
Max | Min | Max | Min | Max | |
4-40 | .1105 | .1095 | .1055 | .090 | |
6-32 | .1410 | .1350 | .1350 | .1290 | .111 |
8-32 | .1670 | .1610 | .1610 | .1550 | .137 |
10-24 | .1940 | .1880 | .1860 | .1800 | .153 |
10-32 | .1930 | .1870 | .1870 | .1810 | .163 |
1/4-20 | .2550 | .2490 | .2450 | .2390 | .206 |
5/16-18 | .3180 | .3120 | .307 | .301 | .264 |
3/8-16 | .3810 | .3750 | .3685 | .3625 | .320 |
Nominal Screw Length | |||||
Tolerance on Length | Nominal Screw Size | To 1/2" to 1" Incl. | Over 1/2" to 1" Incl. | Over 1" to 2" Incl. | Over 2" |
#4 - #10 | +0. - .030 | +0. - .030 | +0. - .060 | +0. - .090 | |
1/4" - 3/8" | +0. - .030 | +0. - .030 | +0. - .060 | +0. - .090 |
Description | Trilobular thread-rolling screw .As each lobs of the screw moves through the pilot hole in the nut material . it forms and work ,hardens the nut thread metal , producing an uninterrupted grain flow. |
Applications / Advantages | For drilled , punched or corred holes in all ductlle metals and punch extruded metals .Eliminates chips ,requires low drive torque and provides excellent resistance to vibrational loosening. |
Material | AISI 1022 steel |
Heat Treatment | Screws shall be quenched in liquid and then tempered by reheating to 650°F minimum. |
Case Hardness | Rockwell C45 minimum. |
Case Depth | 4-40 & 6-32 diameters : .002 - .007 / 8-32 , 10-24 & 10-32 diameters : .004 - .009 1/4-20 diameters & larger :. .005 - .011 |
Core Hardness (after tempering) | Rockwell C28-38 |