An Overview of the Different Grades of the Automation Locknuts

Fasteners especially those small in size are ideally not graded means their strength is not specified. On the other hand, the larger sized and those for specialized purposes are made to meet certain set requirements. Automation locknuts are the need of the industry. They are available in strength grades A, B and C.

These locknuts are available in almost all types of plating including phosphate & oil, cadmium, and trivalent/hexavalent zinc. The two most popular types of automation locknuts are 1) Inch fasteners – they come with a grade or with ASTM rating, 2) Metric Fasteners that has special markings on heads used to identify the locknut’s grade.

Metric Class – Tensile strength is the most widely associated property of the threaded fastener. And it is the maximum tension applied that the fastener can support before its fracture, which is considered as the ultimate tensile strength.

• The strength grades or class of the metric fastener – The grades in the metric fastener are defined by two numbers which are separated by a dot. The increasing numbers represent the increasing tensile strength. While the number to the left of the dot indicates the ultimate tensile strength in Mpa divided by 100. The ratio between yield strength and tensile strength is written on the right to the dot.

Inch Fastener Grades – These bolts have a mark on their head. This mark is actually the grade of the bolt that helps the manufacturers in identification.

• Grade 2 – They are commercial low tensile bolts and do not have any grade marking. Their strength is similar to European metric class 4.6.

• Grade 5 – They are the most commonly found locknuts in automotive applications. Their material has the similar strength as European metric class 8.8.

• Grade 8 – They are stronger than the grade 5 nuts and are made up of the alloy. They are widely used in high-performance applications. Their material has the similar strength as European metric class 10.9.

Stainless Steel Grades – The commercially used automation locknuts are made up of austenitic stainless steels which are given the designation letter ‘A’. This material is corrosion resistant and is widely used in the production of stainless steel fasteners.

When it comes to austenitic steel, they are divided into three important alloy classes. The most common being the A2. If increased corrosion resistance is required, the marine grade A4 is available for the commercial class.

Since 30 years of establishment, TriState Locknuts has been a consistent renowned manufacturer and processor of automation locknuts of all grades. Our trademark is registered with US Patent and Trademark Office and with DISC. We are also an approved supplier of automation locknuts to the government.