NOTE: This is a legacy product, now superseded by the POWERLOK® II™ fastener

POWERLOK® exceeds IFI locking screw standards - it has locking action you can't wear out!

Applications - Already in use in automotive and other mass-assembly operations.  You can use POWERLOK® screws wherever you need reliable vibration resistance and continued high performance despite repeated assembly/disassembly - using normal tapped holes. These fasteners can be used in pre-tapped holes in ductile metals.


  • Enhanced locking ability
  • Continuous locking action
  • Resistant to high temperatures
  • Reusable
  • No special taps

Standard Material - 1022, 10B21 or 4037 steel hardened and tempered to the optimum combination of tensile strength and toughness.   Tensile or torsional strength can be more than twice that of machine screws.  Screws can be made in strength levels to suit a wide range of application requirements. Property Class 10.9 is often preferred.  Finishes can be supplied as required.

Reusable - Subjecting the POWERLOK® screw to increasing clamp load results in continuously increasing thread flank contact so that unit pressure between mating surfaces tends to remain constant, an important factor in diminishing galling and abrasion.  Together with the burnishing action of the TRILOBULAR® crests, this means continued locking effectiveness after repeated insertions and removals.  Locking performance - Will meet or exceed IFI 124 (inch) or IFI 524 (metric) Specifications for Prevailing Torque Locking Screws.  Transverse vibration test data available upon request.  Actual performance will vary depending on effective finish lubricity and nut condition.  No special taps - You save time and money by using a regular nut or Class 2B (6G) tapped hole. POWERLOK® is precision made - so the hole thread doesn't have to be.

Enhanced locking ability - "POWERLOK®, the TRILOBULAR® self locking screw is a unique concept in locking screws."  Made from high strength steel, hardened and tempered to an optimum strength-toughness serviceability, the POWERLOK® screw achieves enhanced locking ability through the combination of a novel 60° - 30° thread form and a TRILOBULAR® thread body section.  A significant mechanical advantage of this design is that the locking action is developed at the outermost radius of the torque arm of the screw body whereas other locking screws develop their effective resistance at lesser radius points on thread flanks, even down to the thread root surface.  The deeper geometry of the POWERLOK® thread, along with a slight increase in the thread major diameter over equivalent size machine screw, adds to the effective stripping resistance of the fastener.   In addition, the centrality of the POWERLOK® lobes in the nut member thread allows the 30° thread crest on the fastener to flex elastically under clamp load, simulating the live action of spring washers.

Continuous locking action - POWERLOK® screws do not have to be seated to lock as the locking thread feature extends the entire length of the fastener.  They resist vibration at any point along their body length.  POWERLOK® fasteners are excellent adjusting screws.  The locking action is instantaneous and unlike chemical locking agents, no reaction or curing time is required.

Resistant to high temperatures - POWERLOK® screws do not lose their action or efficiency in high temperature environments.  Non-metallic additives featured with many locking screws lose much or all of their developed force or deteriorate with time under the influence of a temperature of 200°F or higher.  POWERLOK®, being an all-metal locking fastener, is unaffected by these or higher operating temperatures.

POWERLOK® Documents