teckentrup SLI Screw-locking technology


Eletrical screw connections

  • Overview
  • Functional principle
  • Quality assurance
  • Dimension
  • Application areas
  • Downloads

In electrical engineering, loose screw connections inevitably lead to system failure and high damage risks. The conductive materials used, made of copper and aluminum, are tightened with reduced torque due to the soft counter layers.

Currently, screw locking is very often done by a combination of flat washer and lock washer. However, settling or creeping effects and the resulting loss of preload force cannot be compensated by this. There is an increased risk with high service maintenance costs.

With the NSK-E you receive a one-piece safety element that meets the increased requirements for electrical screw connections:

  • Counteracts loosening and unscrewing and prevents loosening
  • Preservation of the preload force and contact pressure for soft materials
  • Loss of preload force due to settling is minimized by the high spring effect
  • Danger of chip formation is prevented by the special runner-shaped underside of the disc
  • Simple installation due to one-piece screw locking solution
  • Tested screw locking with short clamping lengths and dynamic loads

Springy, arched geometry

Due to its springy, arched geometry, the NSK-E has a high settling effect and ensures continuous contact pressure between the electrically conductive components, thus avoiding system failures.

Gentle on the counter layer

With the help of a newly developed embossing process, the underside of the NSK-E is smoothed in the shape of a runner. This minimizes the risk of chips coming off and eliminates the need for an additional washer.

Positive locking effect

The serrated washer surface provides a positive locking effect underneath the screw head or nut and counteracts loosening of the screw connection even in the case of high vibrations.

In order to guarantee the functionality of the NSK-E, a multi-stage product test is carried out that goes beyond the requirements of the standard:

Residual spring force analysis according to DIN 267-26

Dynamic screw-locking test based on DIN 65161 or the increased requirements of DIN 25201-4 Annex B, including the specific application features of the electrical sector.

Vibration, shock and temperature tests according to test standard IEC 61373 by railway testing company AUCOTEAM

Galvanised spring steel

NSK E Article no. DA S H
NSK E3 070905 Ø 7.10-0.30 1.00±0.05 1.10+0.20
NSK E4 070910 Ø 9.10-0.40 1.20±0.05 1.30+0.20
NSK E5 070920 Ø 9.10-0.40 1.20±0.05 1.50+0.20
NSK E6 070930 Ø 12.10-0.43 1.60±0.05 1.70+0.20
NSK E8 070940 Ø 16.10-0.43 1.60±0.05 2.20+0.25
NSK E10 070950 Ø 20.10-0.52 1.80±0.10 2.30+0.35
NSK E12 070960 Ø 24.10-0.52 2.00±0.10 2.50+0.35
NSK E16 070980 Ø 30.10-0.52 2.20±0.10 2.70+0.35

subject to technical changes

Stainless steel A4 1.4401

NSK E Artikelnummer DA S H
NSK E3 070905 Ø 7.30-0.40 1.00±0.05 1.10+0.20
NSK E4 076910 Ø 9.40-0.40 1.2±0.05 1.90+0.20
NSK E5 076920 Ø 10.10-0.40 1.2±0.05 2.00+0.20
NSK E6 076930 Ø 12.10-0.43 2.25±0.075 2.20+0.20
NSK E8 076940 Ø 16.10-0.43 2.25±0.075 2.80+0.25
NSK E10 076950 Ø 20.10-0.52 2.4±0.10 3.00+0.35
NSK E12 076960 Ø 24.10-0.52 2.7±0.10 3.40+0.35
NSK E16 076980 Ø 30.10-0.52 3.0±0.10 3.60+0.35

subject to technical changes

Areas of application in which the NSK-E is used.

Electric mobility
Wind power