What is an M24x12 screw

Strength class 12.9

The Strength class 12.9 describes the quality and tensile strength of all connecting elements and securing elements in fastening technology such as screws, nuts and threaded rods.

With this strength class 12.9, fastening elements are divided into individual standards and all other building materials are classified according to their quality and named and labeled accordingly.

Property class 12.9 the quality for screws, nuts and threaded rods

What does quality and strength class 12.9 mean for bolts and nuts?

The strength class marking and quality assessments within the fastening technology and connection technology, e.g. for screws and nuts and all other connection elements made of steel, consists of two numbers (e.g. for this the 12.9 ) separated by a point.

The number on the left (e.g. 4, 5, 8, 10 or 12) corresponds to 1/100 of the nominal tensile strength with the specification in N / mm².

The right number (e.g. 6, 8 or 9) indicates ten times the ratio of the lower yield point to the nominal tensile strength of the stressed connection.

The strength class 12.9 is called:

A tensile strength of 1200 N / mm² (first number x 100 multiplied = 12 x 100 = 1200 N / mm² )

And a yield strength of 1080 N / mm² (first number x second number multiplied, x 10 multiplied = 12 x 9 = 108 x 10 = 1080 N / mm² )