Nominal diameter
(mm)

Tolerance
(mm)

Tensile strength
No less
than
(MPa)

Off-proportion extension stress   no less than
(kN)

Elongation no less than L₀=200mm
(%)

Bending test

Relaxation value 1000h  no more than

Times/ 180°
No less than

radius
 (mm)

Ⅰ

Ⅱ

5.00

±0.05

1470
1570
1670
1770

1250
1330
1410
1500

4

4

15

8

2.5

6.00

±0.05

1570
1670

1330
1420

4

4

15

8

2.5

7.00

±0.05

1470
1570

1250
1330

4

4

20

8

2.5

Nominal diameter
(mm)

Tensile strength
No less
Than
(MPa)

Off-proportion extension stress   no less than
(kN)

Elongation no less than L₀=200mm
(%)

Bending test

Relaxation Value 1000h  no more than

Times/ 180°
No less than

radius 
(mm)

Ⅰ

Ⅱ

≤5.00

1470
1570

1250
1330

3.5

3

15

8

2.5

>5.00

1470
1570

1250
1340

20

Nominal Dia.
(mm)

Spiral ribs number
（Item）

Spiral ribs nominal size

Retortion time
（>=）

Dia of base circle
（D1）
  (mm)

Dia of out profile
（D）
  (mm)

Single rib size

Spiral rib length perimeter
（C）
mm/360°

Width
（a）
(mm)

Height
（b）
 (mm)

4.00

4

3.85±0.05

4.25±0.05

0.90-1.30

0.20±0.05

24.00-30.00

4.80

4

4.60±0.05

5.10±0.05

1.30-1.70

0.25±0.05

28.00-36.00

5.00

4

4.80±0.05

5.30±0.05

1.30-1.70

0.25±0.05

28.00-36.00

6.00

4

5.80±0.05

6.30±0.05

1.60-2.00

0.35±0.05

30.00-38.00

7.00

4

6.70±0.05

7.46±0.10

1.80-2.20

0.40±0.05

35.00-45.00

8.00

4

7.70±0.05

8.45±0.10

2.00-2.40

0.45±0.05

40.00-50.00