Proof load of stainless steel nuts, fine thread
Steel nuts (coarse thread)ISO 898-2 (JIS B 1052-2)Unlike bolts, the proof stress rises with nominal diameter within the same property class. Steel nuts (fine thread)ISO 898-6 (JIS B 1052-6)A separate standard from the coarse thread. At the same property class the stress is higher, and the range of nominal diameters is narrower.Stainless steel nuts (coarse thread)ISO 3506-2 (JIS B 1054-2)The proof stress does not change with the nominal diameter; it splits into two according to the nut height.Stainless steel nuts (fine thread)ISO 3506-2 (JIS B 1054-2)The proof stress is the same as for the coarse thread. The larger stress area makes the proof load larger by the same amount.
Notes
- The proof load is the effective sectional area multiplied by the proof stress. The effective sectional area is calculated as given in JIS B 1082. The source has no proof load table. The standard goes only as far as the proof stress.
- Fine thread nuts may not meet the proof load requirement. The source states that, because of the fine thread or the shape of the nut, some nuts may not meet the proof load requirement.
- The source does not state how the standard height and the thin nut correspond. The standard defines only how to read the three digits: the leading 0 marks a thin nut, and the next two digits are one tenth of the proof stress. halving the stress and rounding down to a multiple of 50 gives exactly one pairing, so that is the order used here (
F1at 45 comes out as 200 rather than 225). - The values here are for room temperature. Mechanical properties change at high and low temperatures, so do not apply these values directly.
- Sources: JIS B 1054-2, JIS B 0205-4, JIS B 1082