1. All dimensions are in inches.

1. 1. To determine nut proof load in pounds, multiply the appropriate nut proof load stress by the tensile stress area of the thread.
2. 2. Non-zinc-coated nuts are nuts intended for use with externally threaded fasteners which have a plain (nonplated or noncoated) finish or have a plating or coating of insufficient thickness to necessitate overtapping the nut thread to provide assemblability. Zinc-coated nuts are nuts intended for use with externally threaded fasteners which are hot-dip zinc-coated, mechanically zinc-coated, or have a plating or coating of sufficient thickness to necessitate overtapping the nut thread to provide assemblability.

1. 1. The proof load in pounds for nuts is computed by multiplying the proof load stress, in psi (lbf/in2), for the nut grade, size, thread series, and type, as shown in Table 2, and tensile stress area in square inches (in2), for the applicable size and thread series shown in Table 3. (For tabulated values see Appendix A.) To convert the inch based pounds per square inch (psi) values above to metric Megapascal (MPa) units, multiply the above values by .00689.

Grade A & Grade 2 require no material marking

1. 1. For Grade A a sulfur content of 0.23 % max is acceptable with the purchasers approval.

1. 1. Resulfurized and rephosphorized material is not subject to rejection based on check analysis for sulfur.
2. 2. If agreed between purchaser and producer, sulfur content may be 0.23 maximum.