Content with EN 14399-3

08 April 2016
Thread d Nominal stress area of standard test mandarel (mm^2) Property Class 8 (N) Property Class 10 (N) M12 84.3 84300 97800 M16 157 157000 182100 M20 245 245000 284200 M22 303 303000 351200 M24 353 353000 409500 M27 459 459000 532400 M30 561 561000 650800 M36 817 817000 947700 The Proof Load values are based on stress of 1000 MPa for property class 8; and 1160 MPa for property class 10.
Read more about BS EN 14399-3 System HR - Proof Load values for Nuts

18 December 2015
HR (British/French) bolt The British/French approach following BS EN 14399-3 and BS 4395 is to use thick nuts and long thread lengths in the bolt assembly to obtain ductility predominantly by plastic elongation of the bolt. The longer thread length is necessary to ensure that the induced strain is not localised. These bolts are relatively insensitive to overtightening during preloading although suite control is still important. Furthermore if severely over-tightened during preloading the ductile failure mode of the bolt assembly is predominantly by bolt breakage, which is readily detectable.
Read more about What is the difference between HR and HV bolt assemblies?