Axial Strength and Tightening Torque – Types LAC/LAS/LA4
PDF page 12 · PEM Fastener Catalogue
Unified
| Thread Code | Locknut Min. Axial Strength(1) (lbs.) | Mating Screw Strength Level(1) (ksi) | Mating Screw Tightening Torque(2) (in. lbs.) |
|---|---|---|---|
| 440 | 1085 | 180 | 15.8 |
| 632 | 1636 | 180 | 29.4 |
| 832 | 2522 | 180 | 53.8 |
| 032 | 3600 | 180 | 88.9 |
| 0420 | 5728 | 180 | 186 |
Metric
| Thread Code | Locknut Min. Axial Strength(1) (kN) | Mating Screw Strength Level(1) (MPa) | Mating Screw Tightening Torque(2) (N•m) |
|---|---|---|---|
| M3 | 6.14 | 1220 | 2.39 |
| M4 | 10.71 | 1220 | 5.57 |
| M5 | 17.3 | 1220 | 11.2 |
| M6 | 24.55 | 1220 | 19.1 |
(1) All LAC, LAS and LA4 locknuts have axial strength exceeding the minimum tensile strength of 180 ksi/Property Class 12.9 screws. Contact techsupport regarding assemble strength for higher strength screws.
(2) Tightening torque shown will induce preload of 65% of locknut minimum axial strength with K or nut factor is equal to 0.20. In some applications tightening torque may need to be adjusted based on the actual K value. All tightening torques shown are based on 180 ksi/ Property Class 12.9 screws. For lower strength screws the tightening torque is proportionately less. For example, for 120 ksi screws, torque is 67% value shown. For 900 MPa screws (Property Class 9.8) torque value is 74% of value shown.
Fastener drawings and models are available at www.pemnet.com
A Note About Hardened 400 Series Stainless Steel
In order for self-clinching fasteners to work properly, the fastener must be harder than the sheet into which it is being installed. In the case of stainless steel panels, fasteners made from 300 Series Stainless Steel do not meet this hardness criteria. It is for this reason that A4 and LA4 400 series fasteners are offered. However, while these 400 Series fasteners install and perform well in 300 Series stainless sheets they should not be used if the end product:
- Will be exposed to any appreciable corrosive presence.
- Requires non-magnetic fasteners.
- Will be exposed to any temperatures above 300°F (149°C)
If any of the these are issues, please contact [email protected] for other options.