Compact, all-metal self-locking nuts with a single slotted collar for secure prevailing-torque locking in tight envelopes.
Auto-Lok single slotted nuts are based on proven industrial fastening principles, using a single slotted collar above the hexagon to create a reliable self-locking mechanism. Compared to the double slotted version, this design uses just one slot, strategically positioned to maximize locking performance while keeping the nut compact.
When tightened, the slotted upper section compresses slightly and grips the bolt thread on the flank — the working surface designed to carry the load. This delivers a streamlined locking solution with consistent prevailing torque and robust performance.
The simplified geometry and lower mass give the single slotted nut excellent reusability and make it ideal for applications where:
- Space is limited and a low-height solution is needed
- Weight reduction is important (e.g. transport and machinery)
- Assemblies are frequently dismantled and reassembled
Depending on your assembly method, the nut can also be installed with the slot engaging the male thread first to achieve specific locking behaviour.
All-metal performance
- All-metal construction for use across a wide temperature range
- Locking performance unaffected by oil, petrol, or common industrial liquids
- Suitable for hand tools or powered assembly
- Can be used against a bearing face or without one
Standard finishes for Auto-Lok single slotted nuts include zinc and chromate passivation or self-colour for metric threads. Additional coatings and finishes are available for non-metric versions. On request, we can supply special materials, finishes and custom designs to match your application and standards (subject to minimum order quantities).
Available single slotted variants
Low Height — H = 0.8D
Compact version for tight stackups and limited axial space.
Normal Height — H = 1D
Standard single slotted Auto-Lok® nut for general industrial use.
High Height — H = 1.3D
Taller design for higher clamp loads or thicker clamped stacks.