Dimensions of metric hex nuts with fine pitch thread are shown in the following chart according to ISO 8673, ISO 8674 and ISO 4759-1 standards.
Some important notes from the ISO standards about hex nuts with metric fine thread:
- ISO 8673 specifies the characteristics of hex nuts, style 1, with metric fine pitch thread, with nominal thread diameters d from 8 mm up to and including 64 mm, with product grade A for threads d ≤ M16 and product grade B for threads d > M16.
- Mechanical properties of ISO 8673 hex nuts with fine pitch thread: (Steel - d ≤ M39 - Property class 6, 8 , d ≤ M16 - Property class 10) , ( Stainless steel - d ≤ M24: Property class A2-70, A4-70 , M24 < d ≤ M39 - Property class A2-50, A4-50 )
- ISO 8674 specifies the characteristics of hex nuts, style 2, with metric fine pitch thread, with nominal thread diameters d from 8 mm up to and including 36 mm, with product grade A for threads d ≤ M16 and product grade B for threads d > M16.
- Mechanical properties of ISO 8674 hex nuts with fine pitch thread: Steel - d ≤ M16 - Property class 8 and 12, d ≤ M36 - Property class 10
Note 1: Dimensions are in mm.
Note 2: Requirements for electroplating are covered in ISO 4042 for steel nuts
Note 3: Requirements for nonelectrolytically applied zinc flake coatings are covered in ISO 10683 for steel nuts.
Note 4: Non-preferred threads according to ISO standards: M10 x 1.25, M12 x 1.25, M14 x 1.5, M18 x 1.5, M20 x 2, M22 x 1.5, M27 x 2, M33 x 2, M39 x 3, M45 x 3, M52 x 4, M60 x 4.
Note 5: Thread tolerance of hex thin nuts is 6H.
Product Grade A, Grade B and Grade C: The product grades refer to the size of the tolerances where grade A is the most precise and grade C is the least precise as defined in the ISO 4759-1:2000 standard.