Locking screwed connections
Ribbed and toothed products were the first locking elements with locking teeth or serration. Introduced to the market more than 40 years ago, they have been sold in millions and proved effective solutions for locking screwed connections.
Characteristics
The functional principle of this locking method is based on embossed teeth that are arranged in a way that the steeper flank is aligned in unscrewing direction. Upon tightening, these form elements dig into the component and create a form fit that has to be overcome upon loosening.
Technical notes
ZAHN screws and nuts
- 24 locking teeth block the internal unscrewing torque in unscrewing direction.
- The elastic flange compensates setting and reduces the decrease in clamping force.
- The smooth internal washer face transmits the clamping force.
- No stronger setting than for normal screws
RIPP screws and nuts
- The locking serrations cover the entire contact surface of the screw or nut. Thus, force transmission is executed on the entire surface.
- During tightening, the contact material in the area of the screw support is "roller-burnished" by the locking serrations. This results in surface-hardening plastic deformation.
- After completing tightening, no considerable flowing (setting) is detected.
Property classes
| Fastener | Property class |
|---|---|
| Screws | PC 100, case-hardened and tempered, 1,040 - ( 1,200 ) N/mm² |
| PC 10.9, according to DIN ISO 898/1 | |
| PC 12.9, according to DIN ISO 898/ | |
| Nuts | PC 10, case-hardened and tempered |
| PC 12, case-hardened and tempered |
Benefits
Using RIPP and ZAHN locking elements provides you considerable benefits:
- Reliable locking of joints without additional elements
- No washers required due to enhanced contact surface
- Reduced setting values of screws due to consolidation of materials to be braced
- Favourable tightening behaviour, excellent reusability
- Surface-friendly locking, small damage to the area of the contact surfaces
- Comprehensive warehouse program
- Short lead times
