Boron Steel for Grade 5 Bolts Boron Steel for Grade 5 Bolts Bagyo (Mechanical) (OP) 8 Nov 06 16:51 Is 10B21 Boron Steel acceptable to be used for Grade 5 Bolts? Where can I find the specification for this?Thanks,Bagyo RE: Boron Steel for Grade 5 Bolts swall (Materials) 8 Nov 06 19:22 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. RE: Boron Steel for Grade 5 Bolts swall (Materials) 9 Nov 06 09:15 You want SAE J429. 10B21 is allowed, with a restriction that Mn must be .74 min. and .0005 min on B. Proper designation of this grade fastener is 5.2. RE: Boron Steel for Grade 5 Bolts Bagyo (Mechanical) (OP) 9 Nov 06 11:50 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 RE: Boron Steel for Grade 5 Bolts CoryPad (Materials) 9 Nov 06 14:32 Yes Regards,CoryPlease see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora. RE: Boron Steel for Grade 5 Bolts TVP (Materials) 10 Nov 06 09:24 Bagyo,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.