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Proof load of 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)並目ねじとは別の規格です。同じ強度区分でも応力が高く、使える呼び径の範囲も狭くなります。Stainless steel nuts (coarse thread)ISO 3506-2 (JIS B 1054-2)保証荷重応力は呼び径では変わらず、ナットの高さで 2 つに分かれます。Stainless steel nuts (fine thread)ISO 3506-2 (JIS B 1054-2)保証荷重応力は並目ねじと同じです。有効断面積が大きくなるぶん、保証荷重も大きくなります。
Thread designationTensile stress area
[mm2]		Proof load [N]

Notes

  • The proof load is the tensile stress area multiplied by the proof stress.The tensile stress area is calculated as given in JIS B 1082.Checked against the table in the source(JIS B 1052-6:2009, Table 6).
  • Fine thread nuts are covered by a separate standard (JIS B 1052-6), with a different range of sizes.Nominal diameters start at 8 mm, and There is no property class 9. Only the 19 designations covered by the source appear in the table, three more than the bolt standard (JIS B 1051) covers (M18×2, M20×2 and M22×2).A blank means that that property class is not specified for that size (classes 10 and 12 apply only up to 16 mm).
  • For the same property class the proof stress is higher than for coarse thread.For class 8 it is 955 to 1090 N/mm2, against 855 to 920 N/mm2 for coarse thread. A fine thread is weaker, so more is asked of the nut.
  • 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 1052-6, JIS B 0205-4, JIS B 1082
Nuts — Proof load — Proof load of steel nuts, fine thread | Updraft - Mechanical Engineering Calculators