It depends. I will look up the SAE spec tomorrow at work. If I recall, when supplier and purchaser agree and the mech properties are met, the use of 10B21 is acceptable.
Swall,
Thanks for your input. I received grade 5 cap screws from our supplier and when I checked the Material Test Report, the products were made from 10B21 boron steel but the head marking is still with grade 5 not 5.2. The products passed the mechanical testing equivalent to grade 5 as per SAE J429. Do I have the right to reject the products because they were not designated appropriately?
Thank you
The replies from swall and CoryPad are both correct. The bolts should have been identified as Grade 5.2 and you do have the right to reject them based on the improper identification. Whether or not you want to do this is a topic for another discussion.
