Automotion Components Self-Locking Fasteners
What is...
Features
This type of fastener is the only fastener that retains its locking torque independent of an axial load. When pre-load is lost, the prevailing torque fastener can prevent the loosening of an assembly subjected to continued shock or vibration.
The nylon strip wedges the fastener against the opposite of the locking device, causing metal-to-metal drag.
A resilient polymer (generally nylon) strip is inserted into a precisely machined slot that is milled into the thread. The strips are typically positioned one to three threads back from the end of the fastener to assure ease of starting.
When assembled with a mating part the strip is compressed and this provides a locking action in the thread. The locking strip is held in place on the thread without the use of adhesives or thread distortion. This results in a reusable fastener that is both locking and repeatedly adjustable.
These self-locking fasteners are produced to IFI 524 standard (requiring a re-usability of up to 15 on/off cycles). The strips will not dry, shrink or lose resiliency when exposed to commercial solvents, alcohol, oil etc.
Standard nylon temperature range (-50°C to +120°C). Other materials available which can off er -250°C to +300°C (with lower reusability cycles).
Installation
We recommend a countersunk or counter-bored clearance hole to aid installation.
Materials
Plated
Locking inserts can be damaged by some plating processes or surface treatments so should never be attempted after user installation.
Please advise Automotion components of any plating requirements when ordering so that the appropriate process can be applied.
Locking insert patches should never be removed by the end user. Removal and replacement will destroy the eff ectiveness of the insert.
Technical Specs
Strip materials
| Materials | Colour code | Operating Temperature Range | Material Specificatiom |
| Polycap Nylon | Green | -50oC to +120oC | ASTM-D-4066 |
| Kel-F®* | Blue | -200oC to +200oC | AMS 3650 |
| Vespel® | Brown | -250oC to +300oC | - |
| Hot-Lok™* | Silver | -250oC to +650oC | - |
*These inserts are not recommended for reuse. Consult Automotion Components for technical details.
Standard "L" dimensions
| Thread | Approx "l" insert length |
| 1,5 | 3,5 |
| 1,8 | 3,5 |
| 2,2 | 4,5 |
| 2,5 | 4,5 |
| 3,0 | 6,0 |
| 3,5 | 7,5 |
| 4,0 | 8,5 |
| 5,0 | 8,5 |
| 6,5 | 11,0 |
| 8,0 | 10,7 |
| 9,5 | 12,0 |
| 11,5 | 13,5 |
| 12,5 | 14,0 |
| 14,0 | 14,5 |
| 16,0 | 16,0 |
| 19,0 | 19,0 |
| 22,0 | 19,0 |
| 25,0 | 19,0 |
Insert length can be affected by overall length of thread.
