直径d

(或边长a)

／mm

精度组别

截面面积／cm²

理论质量(kg／m)

1组

2组

3组

圆  钢

方  钢

圆 钢

方  钢

允许偏差／mm

5.5

±0.20

±0.30

±0.40

..2375

0.30

0.186

0.237

6

0.2827

0.36

0.222

0.283

6.5

0.3318

0.42

0.260

0.332

7

0.3848

0.49

0.302

0.385

8

±0.25

±0.35

±0.40

0.5077

0.64

0.395

0.502

9

0.6362

0.81

0.499

0.636

10

0.7854

1.0

0.617

0.785

*11

0.9503

1.21

0.746

0.95

12

1.131

1.44

0.888

1.13

13

1.327

1.69

1.04

1.33

14

1.539

1.96

1.21

1.54

15

1.767

2.25

1.39

1.77

16

2.011

2.56

1.58

2.01

17

2.270

2.89

1.78

2.27

18

2.545

3.24

2.00

2.54

19

2.835

3.61

2.23

2.83

20

3.142

4.00

2.47

3.14

21

±. 30

±. 40

±. 50

3.464

4.41

2.72

3.46

22

3.801

4.84

2.98

3.80

*23

4.155

5.29

3.26

4.15

24

4.524

5.76

3.55

4.52

25

4.909

6.25

3.85

4.91

26

5.309

6.76

4.17

5.31

*27

5.726

7.29

4.49

5.72

28

6.158

7.84

4.83

6.15

*29

6.605

8.41

5.18

6.60

30

7.069

9.00

5.55

7.06

*31

±0.40

±0.50

±0.60

7.548

9.61

5.93

7.54

32

8.042

10.24

6.31

8.04

*33

8.553

10.89

6.71

8.55

34

9.097

11.56

7.13

9.07

*35

9.621

12.25

7.55

9.62

36

10.18

12.96

7.99

10.2

38

11.34

14.44

8.90

11.3

40

12.57

16.00

9.86

12.6

42

13.85

17.64

10.9

13.8

45

15.90

20.25

12.5

15.9

48

18.10

23.04

14.2

18.1

50

19.64

25.00

15.4

19.6

53

±0.60

±. 70

±0.80

22.06

28.09

17.3

22..

*55

23.76

30.25

18.6

23.7