BS A 319:1997 Nuts, hexagonal, plain, reduced height, reduced across flats, with MJ threads, classifications: 450 MPa (at ambient temperature)/425 degreesC, 600 MPa (at ambient temperature)/235 degreesC, 600 MPa (at ambient temperature)/315 degreesC, 600 MPa (at ambient temperature)/650 degreesC, 900 MPa (at ambi

standard by BSI Group, 10/15/1997