ISO 898-2 Carbon Steel and Alloy Steel - Nuts

ISO 898-2:2022 Fasteners - Mechanical properties of fasteners made of carbon steel and alloy steel – Part 2: Nuts with specified property classes

Chemical composition as per ISO 898-2:2022 for typical grades

ClassMaterial and TreatmentCMn
min.
P
max.
S
max.
8
(M16 and below)
carbon steel NOT quenched and tempered (NQT)0.06-0.580.250.0600.150
8carbon steel quenched and tempered (QT)0.15-0.580.450.0480.058
10carbon steel quenched and tempered (QT)0.15-0.580.450.0480.058
12
(like ISO 4032)
carbon steel quenched and tempered (QT)0.18-0.580.450.0480.058
12
(like ISO 4033)
carbon steel quenched and tempered (QT)0.15-0.580.450.0480.058

Hardness requirement as per ISO 898-2:2022 for typical grades

Hardness scaleSizeClass 8
min.
Class 8
max.
Class 10
min.
Class 10
max.
Class 12
min.
Class 12
max.
Vickers, HVM5 to M16 (NQT)200334
Vickers, HVM5 to M16 (QT)200334272353308368
Vickers, HVabove M16 to M39 (QT)233334272353
Vickers, HV
(like ISO 4033)
M5 to M16 (QT)272353
Brinell, HB or HBWM5 to M16 (NQT)190318
Brinell, HB or HBWM5 to M16 (QT)195195268349304363
Brinell, HB or HBWabove M16 to M39 (QT)233228268349
Brinell, HB or HBW
(like ISO 4033)
M5 to M16 (QT)268349
Rockwell, HRCM5 to M16 (NQT)33.9
Rockwell, HRCM5 to M16 (QT)34.826.536.931.638.5
Rockwell, HRCabove M16 to M39 (QT)34.826.536.9
Rockwell, HRC
(like ISO 4033)
M5 to M16 (QT)26.536.9

Hardness values in Brinell and Rockwell scale for QT are converted from Vickers using ISO 18265

ISO 898-2:2012 Mechanical properties of fasteners made of carbon steel and alloy steel – Part 2: Nuts with specified property classes – Coarse thread and fine pitch thread

Chemical composition as per ISO 898-2:2012 for typical grades

ClassMaterial and TreatmentC
max.
Mn
min.
P
max.
S
max.
8
(M16 and below)
carbon steel (may be quenched and tempered)0.580.250.0600.150
8
(above M16)
carbon steel quenched and tempered0.580.300.0480.058
10carbon steel quenched and tempered0.580.300.0480.058
12carbon steel quenched and tempered0.580.450.0480.058

Hardness requirement as per ISO 898-2:2012 for typical grades

Hardness scaleSizeClass 8
min.
Class 8
max.
Class 10
min.
Class 10
max.
Class 12
min.
Class 12
max.
Vickers, HVM5 to M16200302272353295353
Vickers, HVabove M16 to M39233353272353272353
Brinell, HBM5 to M16190287259336280336
Brinell, HBabove M16 to M39221336259336259336
Rockwell, HRCM5 to M163026362936

Whilst the information is provided in good faith, Andrews Fasteners Ltd are not under any responsibility or liability in respect of errors or information that was found to be incorrect or for any reliance the user may place on it.

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