Slotted Nuts

Slotted nuts, also known as castellated nuts, have grooved heads that align with holes in the mated bolt to accept the insertion of a cotter pin, locking the nut in place. They are commonly used to ensure that shaft components in certain automotive assemblies do not separate or to maintain machine settings in manufacturing environments.



Nothing has been done to this bare metal surface to improve appearance or corrosion resistance, which is very low if the material is steel. Often the surface has been oiled which improves lubricity. This finish is susceptible to rusting and corrosion in exterior environments. This most basic finish can be used when protection is not an issue or indoors.

This finish, also know as zinc plating, zinc chromate or dichromate provides good corrosion resistance and is the standard for many hardware fasteners. It is an electroplated zinc layer covered with a chromate post-treatment. The zinc protects the steel from corrosion and the chromate layer protects the zinc from degrading. It is a popular finish because of its protection, value, and ease of coating. Slightly less corrosion resistant than yellow zinc, it is a versatile finish that is best used indoors. This finish should not be used in marine or high salt spray environments.



This grade is from the SAE scale and made of low carbon steel. This classification is low on the grade scale.

This is a high pressure and temperature grade nut made of medium carbon steel that has been quenched and tempered. This grade meets ASTM specification A 194. These nuts are also used in flanges and fittings as well as in heavy construction of buildings and bridges.

This grade is from the SAE scale. Made of medium to low carbon steel, it is of medium strength on the grade scale.

This grade is part of the SAE classification; it is the minimum standard of the automotive and structural industries, plus it is used in high-temperature applications. Grade 8 is near the high end of the grade scale, although there are higher grades and strengths for more specialized fasteners.


Stainless Steel

Stainless steel is steel combined with alloying elements, principally chromium, to enhance corrosion resistance and impart other desired properties depending upon the alloying elements in use and their proportions. Many stainless steel fasteners are non-magnetic or less magnetic than regular steel fasteners.

Steel is the most common fastener material due to its strength properties. Unalloyed steel may be surface treated to enhance corrosion resistance and other desirable properties.



Meets ASTM standards for hex nuts for a certain range of sizes, metric and Imperial.
DIN 935

German Standards for slotted hexagonal nuts.