ISO 3506-2 Grade A4-70

ISO 3506-2 Grades

Chemical and Mechanical properties of corrosion resistance stainless steel Hex nuts
Stainless steel hex nuts as per ISO 3506-2 Grade A4-70

ISO 3506-2 specifies the mechanical and chemical properties for hexagon nut in grade A4-70 and made of austenitic and ferritic steel grades of corrosion resistance stainless steel grade. This standard and its part mainly pertains to hexagon nuts with nominal diameter up to M-39 or 39 mm.

A4-70 means that A4 which stands for series 316 material and 70 which means the strength of the hexagon nut.

ISO 3506-2 Grade A4-70
A4-70 Hex Nuts, Jam Nut, Lock Nut & Thin Nuts
ISO 3506-2 Grade A Series Chemical properties

Steel Group

Steel Grade

Chemical composition

mass fraction, % (maxima unless stated))

C

Si

Mn

P

S

Cr

Mo

Ni

Cu

Austenitic

A1

0.12

1

6.5

0.2

0.15 to 0.35

16 to 19

0.7

5 to 10

1.75 to 2.25

A2

0.10

1

2

0.05

0.03

15 to 20

-

8 to 19

4

A3

0.08

1

2

0.045

0.03

17 to 19

-

9 to 12

1

A4

0.08

1

2

0.045

0.03

16 to 18.5

2 to 3

10 to 15

4

A5

0.08

1

2

0.045

0.03

16 to 18.5

2 to 3

10.5 to 14

1

ISO 3506-2 Grade A Series Mechanical properties

Steel Group

Steel Grade

Property Class

Stress Under proof load Sp

min. MPA

Nuts with m ≥ 0.8d

Nuts with 0.5d ≤ m < 0.8d

Nuts with m ≥ 0.8d

Nuts with 0.5d ≤ m < 0.8d

Austenitic

A1, A2

50

025

500

250

A3, A4

70

035

700

350

A5

80

040

800

400