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Westfield Fasteners Product Specification:

DIN 7985 - Pozi Pan Head Screws (type Z recess)

This product guide contains the specification for metric threaded pozi pan head screws as available from Westfield Fasteners. The basis of this specification is the DIN standard DIN 7985, but this specification may include information on sizes and materials that are not covered by the DIN standard but are available.

Product Description

A machine screw with a pozi drive, designed to be tightened with a screwdriver. Typically found on consumer electronics and other small machinery where high torque fasteners are not necessary.

Scope of the DIN Standard

DIN 7985 specifies the tolerances and the permissable variation in form of phillips pan head machine screws, and covers metric thread diameters from M1.6 to M10 inclusive. The DIN 7985 standard covers both pozi (type Z) and phillips (type H) drives. Table 1 below defines the overall dimensions and tolerances of this screw type. Table 2 defines the tolerance on the shank length.

Although the DIN 7985 standard has now been superceded by ISO 7045, off the shelf parts are generally still manufactured to the older specification. The ISO standard specifies slightly smaller head diameters for M3 and M5, and slightly smaller head heights for M2.5, M3.5 and M5.

Table 1: Dimensions & Tolerances according to DIN 7985

Thread, d	M1.6	M2	M2.5	M3	M3.5	M4	M5	M6	M8	M10
p	0.35	0.4	0.45	0.5	0.6	0.7	0.8	1	1.25	1.5
a	max	0.7	0.8	0.9	1	1.2	1.4	1.6	2	2.5	3
b	min	15	16	18	19	20	22	25	28	34	40
d_a	max	2.1	2.6	3.1	3.6	4.1	4.7	5.7	6.8	9.2	11.2
d_k	nom=max	3.2	4	5	6	7	8	10	12	16	20
min	2.9	3.7	4.7	5.7	6.64	7.64	9.64	11.57	15.57	19.48
k	nom	1.3	1.6	2	2.4	2.7	3.1	3.8	4.6	6	7.5
max	1.42	1.72	2.12	2.52	2.82	3.25	3.95	4.75	6.15	7.68
min	1.18	1.48	1.88	2.28	2.58	2.95	3.65	4.45	5.85	7.32
r	min	0.1	0.1	0.1	0.1	0.2	0.2	0.2	0.25	0.4	0.4
r _f	≈	3	4	5	6	7	8	10	12	16	20
x	max	0.8	1.1	1.3	1.6	1.9	2	2.5	3	3.7	4.8
Cross Recess	Recess	no.	0	1	2	3	4
m	ref	1.8	2.5	2.7	3.1	4.2	4.6	5.3	6.8	9	10.2
Type H Penetration	max	1.02	1.4	1.6	2	2.24	2.54	3.27	3.53	4.68	5.88
min	0.72	1.1	1.3	1.7	1.74	2.04	2.77	3.03	4.18	5.38
m	ref	1.8	2.4	2.6	3	4	4.3	5	6.7	8.8	9.9
Type Z Penetration	max	1.17	1.35	1.52	1.93	2.11	2.36	3.1	3.48	4.52	5.69
min	0.92	1.1	1.27	1.68	1.65	1.9	2.64	3.02	4.06	5.23

Thread, d

M1.6

M2.5

M3.5

M10

0.35

0.4

0.45

0.5

0.6

0.7

0.8

1.25

1.5

max

0.7

0.8

0.9

1.2

1.4

1.6

2.5

min

d_a

max

2.1

2.6

3.1

3.6

4.1

4.7

5.7

6.8

9.2

11.2

d_k

nom=max

3.2

min

2.9

3.7

4.7

5.7

6.64

7.64

9.64

11.57

15.57

19.48

nom

1.3

1.6

2.4

2.7

3.1

3.8

4.6

7.5

max

1.42

1.72

2.12

2.52

2.82

3.25

3.95

4.75

6.15

7.68

min

1.18

1.48

1.88

2.28

2.58

2.95

3.65

4.45

5.85

7.32

min

0.1

0.2

0.25

0.4

r _f

≈

max

0.8

1.1

1.3

1.6

1.9

2.5

3.7

4.8

Cross Recess

Recess

no.

ref

1.8

2.5

2.7

3.1

4.2

4.6

5.3

6.8

10.2

Type H Penetration

max

1.02

1.4

1.6

2.24

2.54

3.27

3.53

4.68

5.88

min

0.72

1.1

1.3

1.7

1.74

2.04

2.77

3.03

4.18

5.38

ref

1.8

2.4

2.6

4.3

6.7

8.8

9.9

Type Z Penetration

max

1.17

1.35

1.52

1.93

2.11

2.36

3.1

3.48

4.52

5.69

min

0.92

1.1

1.27

1.68

1.65

1.9

2.64

3.02

4.06

5.23

Shank Length (mm)	+/- (mm)
3	0.2
4-6	0.24
8-10	0.29
12-16	0.35
20-30	0.42
35-50	0.5
55-60	0.92

Shank Length (mm)

+/- (mm)

0.2

4-6

0.24

8-10

0.29

12-16

0.35

20-30

0.42

35-50

0.5

55-60

0.92

DIN 7985 - Pozi Pan Head Screws (type Z recess)

Figure 1: Pozi Pan Head Machine Screw

Table 1: Dimensions & Tolerances according to DIN 7985

Table 2: Shank Length Tolerance according to DIN 7985