Nominal

diameter

(mm)

Allowed

tolerance

(mm)

Tensile 

strength

(Mpa)

Elongation

 (%)

Relaxation

Initial stress

Of % tensile

strength

Loses of stress 

1000 hours

not more than %

Ⅱ

4.00

±0.05

1470

1570

1670

1770

1860

3.5

70

2.0

4.80

70

2.0

5.00

70

2.0

6.00

1470

1570

1670

1770

70

2.0

6.25

70

2.0

7.00

±0.10

70

2.0

8.00

1470

1570

70

2.0

9.00

70

2.0

10.00

1470

70

2.0

12.00

70

2.0