I have a question regarding the materials of screws, nuts, etc.
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A2-70, A2, A4-70, Grade 8.9, Grade 12.9 – what do these mean? How should I make a choice?
A2/A4 represent different materials, and the numbers following them indicate the tensile strength. Read more of what’s available in the design manuals. Don’t ask questions right away. If you look into it yourself, you’ll remember it better
Find the hardware manual; it’s there. In the 12.9 grade, the 12 indicates that the tensile strength is 1200 MPa, while the 9 indicates that the yield strength ratio is 0.9 ； The A in A2 should represent austenitic steel