DIN 981 A spline nut is a nut used to fix coaxial parts on shafts, such as bearings, bushings, ball bearings and other rotating parts. Usually they are lower and smaller in external parameters than standard hex nuts, but they are often used on large shafts, so a design was invented in which they can be tightened with a special wrench that is smaller than a regular open-end wrench of the corresponding nut diameter. The wrench hooks onto one of the splines of the nut with a special tooth and, bending around its body, rests against it, making it possible to apply force when turning it.
DIN 981 fastening group
DIN 981 nuts are most often made of stainless steel and belong to the stainless steel fastener group.
Materials for the manufacture of DIN 981 nuts
DIN 981 nuts are manufactured in the following materials:
- Steel, hardness class 14H
- Stainless steel, grade A2. Strength class A2 allows the bolts to be used at significant temperature changes and in aggressive and humid environments.
Application range of DIN 981 nuts
DIN 981 nuts are widely used in the machine-building industry. The main function of these nuts is to fasten bearings to the shaft and ensure their secure fixation. Even if the connection is subjected to constant vibration and dynamic loads, it remains strong and can withstand any impact.
DIN 981 is directly used on machine tool assemblies, in automotive shock absorbers, bicycle assemblies, photographic lenses, etc.