DIN 931 - ISO 4014

Nominal 

Pitch of thread P

Width across corners e

Width across flats 
s

Thickness of head k

Thread Length b

Transition Diameter da

Dia. of washer face dw

Diameter of unthreaded shank 
ds

Radius under head r

Depth of washer face c

Major Diameter (D)

Pitch Diameter (D1)

Minor Diameter (D2)

MM

Min.

Min.

Max.

Min.

Max.

Bolt 
≤125

Bolt 125-200

Bolt 
≥200

Max.

Min.

Min.

Max.

Min.

Min.

Max.

Min.

Min.

Min.

Max.

Max.

M-16

2.0

26.17

23.16

24

9.71

10.29

38

44

57

17.70

22.00

15.57

16

0.6

0.2

0.8

15.68

15.96

14.50

14.60

13.80

M-18

2.5

29.56

26.16

27

11.15

11.85

42

48

61

20.20

24.85

17.57

18

0.6

0.2

0.8

17.62

17.96

16.15

16.25

15.25

M-20

2.5

32.95

29.16

30

12.15

12.85

46

52

65

22.40

27.70

19.48

20

0.8

0.2

0.8

19.62

19.96

18.15

18.25

17.25

M-22

2.5

37.29

33.00

34

13.65

14.35

50

56

69

24.40

31.35

21.48

22

0.8

0.2

0.8

21.62

21.96

20.15

20.25

19.25

M-24

3.0

39.55

35.00

36

14.65

15.35

54

60

73

26.40

33.25

23.48

24

0.8

0.2

0.8

23.58

23.95

21.80

21.90

20.70

M-27

3.0

45.20

40.00

41

16.65

17.35

60

66

79

30.40

38.00

26.48

27

1.0

0.2

0.8

26.58

26.95

24.80

24.90

23.70

M-30

3.5

50.85

45.00

46

18.18

19.12

66

72

85

33.40

42.75

29.48

30

1.0

0.2

0.8

29.52

29.95

27.50

27.60

26.16

M-33

3.5

55.37

49.00

50

20.58

21.42

72

78

91

36.40

46.55

32.38

33

1.0

0.2

0.8

32.52

32.95

30.50

30.60

29.16

M-36

4.0

60.79

53.80

55

22.08

22.92

78

84

97

39.40

51.11

35.38

36

1.0

0.2

0.8

35.46

35.94

33.15

33.25

31.61

M-39

4.0

66.44

58.80

60

24.58

25.42

84

90

103

42.40

55.86

38.38

39

1.0

0.3

1.0

38.46

38.94

36.20

36.30

34.61

M-42

4.5

71.30

63.10

65

25.58

26.42

90

96

109

45.60

59.95

41.38

42

1.2

0.3

1.0

41.44

41.94

38.80

38.90

37.07

M-45

4.5

76.95

68.10

70

27.58

28.42

96

102

115

48.60

64.70

44.38

45

1.2

0.3

1.0

44.44

44.94

41.80

41.90

40.07

M-48

5.0

82.60

73.10

75

29.58

30.42

102

108

121

52.60

69.45

47.38

48

1.6

0.3

1.0

47.40

47.93

44.50

44.60

42.52

M-52

5.0

88.25

78.10

80

32.50

33.50

110

116

129

56.60

74.20

51.26

52

1.6

0.3

1.0

51.40

51.93

48.50

48.60

46.52

M-56

5.5

93.56

82.80

85

34.50

35.50

118

124

137

63.00

78.66

55.26

56

2.0

0.3

1.0

55.36

55.92

52.10

52.20

49.97

M-60

5.5

99.21

87.80

90

37.50

38.50

-

132

145

67.00

83.41

59.26

60

2.0

0.3

1.0

59.36

59.92

57.85

57.95

53.97

M-64

6.0

104.86

92.80

95

39.50

40.50

-

140

153

71.00

88.16

63.26

64

2.0

0.3

1.0

63.32

63.92

59.80

59.90

57.42