Westfield Fasteners Product Specification:

DIN 917 - Cap Nuts

This product guide contains the specification for metric threaded hexagon cap nuts as available from Westfield Fasteners. The basis of this specification is DIN 917.

Product Description

A closed-end hexagon nut with a domed cap that completely encloses the end of a mating bolt or threaded stud. Cap nuts are commonly used where an attractive finished appearance is required, while also protecting the exposed thread from damage, contamination and corrosion. The smooth closed-end also helps reduce the risk of snagging or accidental contact with exposed threads.

Scope of the DIN standard.

DIN 917 specifies the dimensions, tolerances and permissible variations for hexagon cap nuts (low type) with coarse and fine pitch metric threads, in sizes from M4 up to and including M72.

Table 1: Dimensions & Tolerances according to DIN 917 (mm)

Thread, D	Series 1	M4	M5	M6	M8	M10	M12	M14	M16	M18	M20
Series 2	-	-	-	M8x1	M10x1.25	M12x1.5	M14x1.5	M16x1.5	M16x2	M20x2
Series 3	-	-	-	-	M10x1	M12x1.25	-	-	M18x1.5	M20x1.5
p	0.7	0.8	1	1.25	1.5	1.75	2	2	2.5	2.5
d_a	max	4.60	5.75	6.75	8.75	10.80	13.00	15.10	17.30	19.50	21.60
min	4.00	5.00	6.00	8.00	10.00	12.00	14.00	16.00	18.00	20.00
d_w	min	5.90	6.90	8.90	11.60	14.60	16.60	19.60	22.50	24.90	27.70
e	min	7.66	8.79	11.05	14.38	17.77	20.03	23.35	26.75	29.56	32.95
x	Series 1 max	1.05	1.20	1.50	1.87	2.25	3.5	4	4	5	5
Series 2 max	-	-	-	1.50	1.87	3	3	3	4	4
Series 3 max	-	-	-	-	1.50	2.5	-	-	3	3
g₂	Series 1 max	2.75	3	3.7	4.9	5.6	6.40	7.30	7.30	9.30	9.30
Series 2 max	-	-	-	3.7	4.9	5.60	5.60	5.60	7.30	7.30
Series 3 max	-	-	-	-	3.7	4.90	-	-	5.60	5.60
h	nom=max	5.5	7	9	12	14	16	18	20	22	25
min	5.20	6.64	8.64	11.57	13.57	15.57	17.57	19.48	21.48	24.48
r	approx.	8	10	12	15	20	25	28	30	32	35
s	nom=max	7	8	10	13	16	18	21	24	27	30
min	6.78	7.78	9.78	12.73	15.73	17.73	20.67	23.67	26.16	29.16
t	max	4.64	5.44	7.29	9.79	11.35	13.85	15.35	17.35	19.42	21.42
min	4.16	4.96	6.71	9.21	10.65	13.15	14.65	16.65	18.58	20.58
w	min	1.00	1.00	1.50	2.00	2.00	2.00	2.00	2.00	2.00	2.50

Thread, D

Series 1

M10

M12

M14

M16

M18

M20

Series 2

M8x1

M10x1.25

M12x1.5

M14x1.5

M16x1.5

M16x2

M20x2

Series 3

M10x1

M12x1.25

M18x1.5

M20x1.5

0.7

0.8

1.25

1.5

1.75

2.5

d_a

max

4.60

5.75

6.75

8.75

10.80

13.00

15.10

17.30

19.50

21.60

min

4.00

5.00

6.00

8.00

10.00

12.00

14.00

16.00

18.00

20.00

d_w

min

5.90

6.90

8.90

11.60

14.60

16.60

19.60

22.50

24.90

27.70

min

7.66

8.79

11.05

14.38

17.77

20.03

23.35

26.75

29.56

32.95

Series 1 max

1.05

1.20

1.50

1.87

2.25

3.5

Series 2 max

1.50

1.87

Series 3 max

1.50

2.5

g₂

Series 1 max

2.75

3.7

4.9

5.6

6.40

7.30

9.30

Series 2 max

3.7

4.9

5.60

7.30

Series 3 max

3.7

4.90

5.60

nom=max

5.5

min

5.20

6.64

8.64

11.57

13.57

15.57

17.57

19.48

21.48

24.48

approx.

nom=max

min

6.78

7.78

9.78

12.73

15.73

17.73

20.67

23.67

26.16

29.16

max

4.64

5.44

7.29

9.79

11.35

13.85

15.35

17.35

19.42

21.42

min

4.16

4.96

6.71

9.21

10.65

13.15

14.65

16.65

18.58

20.58

min

1.00

1.50

2.00

2.50

Table 1: Dimensions & Tolerances according to DIN 917 (mm), continued

Thread, D	Series 1	M22	M24	M27	M30	M36	M42	M48	M56	M64	M72X6
Series 2	M22x2	M24x2	M27x2	M30x2	M36x3	M42x3	M48x3	M56x4	M64x4	M72x4
Series 3	M22x1.5	-	-	-	-	-	-	-	-	-
p	2.5	3	3	3.5	4	4.5	5	5.5	6	-
d_a	max	23.70	25.90	29.10	32.40	38.90	45.40	51.80	61.00	69.10	77.80
min	22.00	24.00	27.00	30.00	36.00	42.00	48.00	56.00	64.00	72.00
d_w	min	31.40	33.30	38.00	42.80	51.10	60.00	69.50	78.70	88.20	97.70
e	min	37.29	39.55	45.20	50.85	60.79	72.02	82.30	93.56	104.86	116.16
x	Series 1 max	5	6	6	7	8	9	10	11	12	12
Series 2 max	4	4	4	4	6	6	6	8	8	8
Series 3 max	3	-	-	-	-	-	-	-	-	-
g₂	Series 1 max	9.30	10.70	10.70	12.70	14.00	16.00	18.50	20.00	21.00	21.00
Series 2 max	7.30	7.30	7.30	7.30	10.70	10.70	10.70	14.00	14.00	14.00
Series 3 max	5.60	-	-	-	-	-	-	-	-	-
h	nom=max	28	30	32	34	44	52	58	68	75	85
min	27.48	29.48	31.38	33.38	43.38	51.26	57.26	67.26	74.26	84.13
r	approx.	35	40	50	60	70	80	90	110	130	130
s	nom=max	34	36	41	46	55	65	75	85	95	105
min	33.00	35.00	40.00	45.00	53.80	63.10	73.10	82.80	92.80	102.80
t	max	22.42	24.42	26.42	28.42	36.50	42.50	48.50	56.60	62.60	67.60
min	21.58	23.58	25.58	27.58	35.50	41.50	47.50	55.40	61.40	66.40
w	min	3.00	3.00	3.00	3.00	4.00	4.00	4.00	5.00	5.00	5.00

Thread, D

Series 1

M22

M24

M27

M30

M36

M42

M48

M56

M64

M72X6

Series 2

M22x2

M24x2

M27x2

M30x2

M36x3

M42x3

M48x3

M56x4

M64x4

M72x4

Series 3

M22x1.5

2.5

3.5

4.5

5.5

d_a

max

23.70

25.90

29.10

32.40

38.90

45.40

51.80

61.00

69.10

77.80

min

22.00

24.00

27.00

30.00

36.00

42.00

48.00

56.00

64.00

72.00

d_w

min

31.40

33.30

38.00

42.80

51.10

60.00

69.50

78.70

88.20

97.70

min

37.29

39.55

45.20

50.85

60.79

72.02

82.30

93.56

104.86

116.16

Series 1 max

Series 2 max

Series 3 max

g₂

Series 1 max

9.30

10.70

12.70

14.00

16.00

18.50

20.00

21.00

Series 2 max

7.30

10.70

14.00

Series 3 max

5.60

nom=max

min

27.48

29.48

31.38

33.38

43.38

51.26

57.26

67.26

74.26

84.13

approx.

110

130

nom=max

105

min

33.00

35.00

40.00

45.00

53.80

63.10

73.10

82.80

92.80

102.80

max

22.42

24.42

26.42

28.42

36.50

42.50

48.50

56.60

62.60

67.60

min

21.58

23.58

25.58

27.58

35.50

41.50

47.50

55.40

61.40

66.40

min

3.00

4.00

5.00

DIN 917 - Cap Nuts

Figure 1: DIN 917 Cap Nut

Table 1: Dimensions & Tolerances according to DIN 917 (mm)

Table 1: Dimensions & Tolerances according to DIN 917 (mm), continued