Self-tapping screws

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Thread-forming screw – ST thread

Thread-forming screw – ST thread

Hole recommendation for plate screw

Thread

Plate thickness

Hole diameter d2 H12 or H13 1)

Clearance hole
d4

Steel, brass, copper2)

Aluminium

Cast metal alloy of zinc, magnesium, aluminium and brass

Plastic

Punched or knocked out holes

Drilled or cut holes

Punched or knocked out holes

Drilled or cut holes

Thermosetting plastic

Thermoplastic

Hole group 1A

Hole group 1B

Hole group 2A

Hole group 2B

Hole group 3

Hole group 4

Hole group 5

d2

3)

d2

3)

d2

3)

  

ST 2.2
d1 = 2.24
P = 0.79
U2 = 0.8

- 0.56
(0.56) - 0.75
(0.75) - 0.88
(0.88) - 1.13
(1.13) - 1.38
(1.38) - 1.5

-
-
-
-
-
-

1.6
1.7
1.8
1.8
1.9
1.9

-
-
-
-
-
-

-
1.6
1.6
1.6
1.7
1.8

2

3

2

5

2

5

2.8

ST 2.9
d1 = 2.9
P = 1.06
U2 = 1.1

- 0.56
(0.56) - 0.63
(0.63) - 0.75
(0.75) - 0.88
(0.88) - 1.25
(1.25) - 1.38
(1.38) - 1.75
(1.75) - 2.5

2.2
2.5
2.5
2.5
-
-
-
-

2.2
2.3
2.3
2.4
2.4
2.4
2.5
2.6

-
2.2
2.2
2.2
2.2
-
-
-

-
-
2.2
2.2
2.2
2.2
2.3
2.4

2.7

5

2.5

6.5

2.4

6.5

3.6

ST 3.5
d1 = 3.53
P = 1.27
U2 = 1.3

- 0.56
(0.56) - 0.75
(0.75) - 0.88
(0.88) - 1.25
(1.25) - 1.38
(1.38) - 1.75
(1.75) - 2.5
(2.5) - 3
(3) - 6

2.8
2.8
2.8
-
-
-
-
-
-

2.6
2.7
2.7
2.8
2.8
2.9
3
-
-

-
2.8
2.8
2.8
-
-
-
-
-

-
-
2.6
2.6
2.7
2.8
2.8
3
3

3.3

6.5

3.2

6.5

3

6.5

4.2

ST 4.2
d1 = 4.22
P = 1.41
U2 = 1.4

- 0.5
(0.5) - 0.63
(0.63) - 0.88
(0.88) - 1.13
(1.13) - 1.38
(1.38) - 2.5
(2.5) - 3
(3) - 3.5
(3.5) - 10

3.5
3.5
3.5
3.5
3.5
-
-
-
-

-
3.2
3.2
3.2
3.3
3.5
3.8
3.9
-

-
3.5
3.5
3.5
3.5
-
-
-
-

-
-
2.9
3
3.2
3.5
3.7
3.8
3.9

3.9

6.5

3.8

8

3.7

8

5

ST 4.8
d1 = 4.8
P = 1.59
U2 = 1.6

- 0.5
(0.5) - 0.75
(0.75) - 1.13
(1.13) - 1.38
(1.38) - 1.75
(1.75) - 2.5
(2.5) - 3
(3) - 3.5
(3.5) - 4
(4) - 4.75
(4.75) - 10

4
4
4
4
-
-
-
-
-
-
-

-
3.7
3.7
3.9
3.9
4
4.1
4.3
4.4
4.4
-

-
4
4
4
-
-
-
-
-
-
-

-
-
3.7
3.7
3.7
3.8
3.8
3.9
3.9
4
4.2

4.5

6.4

4.5

8

4.3

8

5.8

ST 5.5
d1 = 5.46
P = 1.81
U2 = 1.8

- 1.13
(1.13) - 1.38
(1.38) - 1.5
(1.5) - 1.75
(1.75) - 2.25
(2.25) - 3
(3) - 3.5
(3.5) -4
(4) - 4.75
(4.75) - 10

4.7
4.7
-
-
-
-
-
-
-
-

4.2
4.3
4.3
4.5
4.6
4.7
5
5
5.1
-

-
-
-
-
-
-
-
-
-
-

-
4.1
4.1
4.2
4.4
4.6
4.6
4.8
4.8
4.9

5

7

5

9.5

4.8

9.5

6.6

ST 6.3
d1 = 6.25
P = 1.81
U2 = 1.8

- 1.38
(1.38) - 1.75
(1.75) - 2
(2) - 3
(3) - 4
(4) - 4.75
(4.75) - 5
(5) - 10

5.3
-
-
-
-
-
-
-

4.9
5
5.2
5.3
5.8
5.9
-
-

-
-
-
-
-
-
-
-

-
5
5
5.2
5.3
5.4
5.6
5.8

5.9

8

5.9

9.5

5.6

8

7.4

1) If H13 is selected, the specified values for d2 must be reduced by 0.1 mm.
2) HB max. 120. In the case of harder materials, the table values are increased by 0.1-0.2 mm.
3) Min. screw-in length. The values in the table apply to case-hardened screws made of steel.For ST threaded screws made of another material, e.g. stainless steel or brass, installation tests should be performed in each individual case.