EN ISO 3506-2 Table 1 - Stainless steel grades - Chemical composition

Group Grade     Chemical composition % C Si Mn   P S Cr Mo Ni Cu Austenitic A1 0.12 1.0 6.50 0.2 0.15 to 0.35 16 to 19 0.7 5 to 10 1.75 to 2.25 A2 0.1 1.0 2.00 0.05 0.03 15 to 20   8 to 19 4.0 A3 0.08 1.0 2.00 0.045 0.03 17 to 19   9 to 12 1.0 A4 0.08 1.0 2.00 0.045 0.03 16 to 18.5 2 to 3 10 to 15 1.0 A5 0.08 1.0 2.00 0.045 0.03 16 to 18.5 2 to 3 10.5 to 14 1.0 Martensitic C1   0.09 to 0.15 1.0 1.00 0.05 0.03 11.5 to 14   1.0   C3   0.17 to 0.25 1.0 1.00 0.04 0.03 16 to 18.5   1.5 to 2.5   C4   0.08 to 0.15 1.0 1.50 0.06 0.15 to 0.35 12 to 14 0.6 1.0   Ferritic F1 0.12 1.0 1.00 0.04 0.03 15 to 18   1.0

EN ISO 3506-2 Table 2 - Mechanical Properties for Nuts - Austenitic Grades

Group Grade Property class Range of thread diameter d mm Stress under proof load S p min. N/mm 2 Nuts style 1 Thin nuts Nuts style 1     Thin nuts (m ≥ 0.8d) (0.5d ≤ m<0.8d) (m ≥ 0.8d)   (0.5d ≤ m<0.8d)   A1 A2, A3 A4, A5 50 025 ≤ 39 500   250 Austenitic 70 035 ≤ 24 700   350 80 040 ≤ 24 800   400

1) For fasteners with nominal thread diameter d>24 mm the mechanical properties shall be agreed upon between user and manufactyrer and ,arked with grade and property class according to this table   EN ISO 3506-2 Table 3 - Mechanical Properties for Nuts - Martensitic and Ferritic Grades   Group Grade Property class Stress under proof load Hardness S p min. N/mm 2 Nuts style 1 Thin nuts Nuts style 1 Thin nuts (m ≥ 0.8d) (0.5d ≤ m<0.8d) (m ≥ 0.8d) (0.5d ≤ m<0.8d) HB HRC HV Martensitic C1 50 025 025 500 250 147 to 209   155 to 220 70     700   209 to 314 20 to 34 220 to 330 110 055 055 1 100 550   36 to 45 350 to 440 C3 80 040 040 800 400 228 to 323 21 to 35 240 to 340 C4 50     500   147 to 209   155 to 220 70 030 030 700 350 209 to 314 20 to 34 220 to 330 Ferritic F1 45 020 020 450 200 128 to 209   135 to 220 60 030 030 600 300 171 to 271   180 to 285 　1) Hardened and tempered at a minimun temperature of 275℃. 　2) Nominal thread diameter d ≤ 24 mm