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Self-Drilling Tek Screws Drill Length

A self-drilling tip include a drill point to drill a starting hole so the threads of the screw can cut and tap into the material, securing it into place.

 

Self Drilling Screw Tek Screw Hex

 

Point Length : Teks screw are distinguished by the length of their drill point. They can be either Tek 1, Tek 2, Tek 3, Tek 4, Tek 5 or Tek 7. Tek 7 being the longest drill point.

Sealing washer : A sealing washer will be added when the connection needs to be waterproof, in roofing application per example.

Wings: Also called Reamers, they are added when attaching wood to metal. They are small portions of metal just above the drill point that make a wider hole in the wood so the threads do not engage until they reach the metal material. Once the wings hit the metal, they snap off.

Dimensions Standard Self Drilling Screws
Dia. Thread Hex Head Point Drill Thick.
6 20 1/4 1 -
6 20 1/4 2 0.035 - 0.090
8 18 1/4 2 0.035 - 0.100
10 16 5/16 2 0.035 - 0.110
10 16 5/16 3 0.110 - 0.175
10 24 5/16 3 0.110 - 0.175
12 14 5/16 2 0.035 - 0.080
12 14 5/16 3 0.110 - 0.175
12 24 5/16 4 0.145 - 0.312
12 24 5/16 5 0.250 - 0.500
12 24 5/16 7 0.500 - 0.750
14(1/4) 14 3/8 3 0.110 - 0.220
14(1/4) 14 3/8 4 0.145 - 0.312
14(1/4) 14 3/8 5 0.250 - 0.500
14(1/4) 14 3/8 7 0.500 - 0.750
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How to determine the Thread Length of your Hex Cap Screws (Imperial/Metric) and Structural Bolts

Looking for the length of the bolt that would be the best for your project? We are here to help.

 

Imperial (Inch)  Standard Thread Length Chart for Bolts

Diameter 

Nominal Thread Length 

Nominal Thread Length 

A325 & A490 

(Inch)

 6" and Less

Greater Than 6"

Thread Length

1/4"

0.75

1

-

5/16"

0.875

1.125

-

3/8"

1

1.25

-

7/16"

1.125

1.375

-

1/2"

1.25

1.5

1

9/16"

1.375

1.625

-

5/8"

1.5

1.75

1.25

3/4"

1.75

2

1.375

7/8"

2

2.25

1.5

1"

2.25

2.5

1.75

1-1/8"

2.5

2.75

2

1-1/4"

2.75

3

2

1-3/8"

3

3.25

2.25

1-1/2"

3.25

3.5

2.25

1-3/4"

3.75

4

-

2"

4.25

4.5

-

2-1/4"

4.75

5

-

2-1/2"

5.25

5.5

-

2-3/4"

5.75

6

-

3"

6.25

6.5

-

3-1/4"

6.75

7

-

3-1/2"

7.25

7.5

-

3-3/4"

7.75

8

-

4"

8.25

8.5

-

Metric (mm) Standard Thread Length Chart For Bolts

Bolt Diameter

Standard Thead Length (mm) *

(mm)

Bolts 125mm and shorter

Bolts >125mm and <125 

Bolts >200mm

M3

12

-

-

M4

14

-

-

M5

16

22

35

M6

18

24

37

M7

20

26

39

M8

22

28

41

M10

26

32

45

M12

30

36

49

M14

34

40

53

M16

38

44

57

M18

42

48

61

M20

46

52

65

M24

54

60

73

M30

66

72

85

M36

78

84

97

M42

90

96

109

M48

102

108

121

M56

-

124

137

M64

-

140

153

M72

-

156

169

M80

-

172

185

M90

-

192

205

M100

-

 212

225

*Please note: Per norm ANSI/ASME B18.2.3.5M-1989

 

 

Here are the maths you will need to do to determine the thread length you will get on standard Hex cap screws.

HOW TO CALCULATE HEX CAP SCREW/HEX BOLT THREAD LENGTH IMPERIAL/METRIC
 

Tap bolts with full thread length might also be available in Imperial and Metric sizes.

Different type of Bolts : EG: Structural Bolts, Carriage Bolts and Lag Bolts will also have different rules for their respective thread length.

When in doubt , contact us at Boulonseclair@boulonseclair.com our team of professionnal will be more than happy to help you.

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How to determine A325 Structural Bolt Length - Structural Bolts Dimensions

The A325 Structural Bolt is used in construction and structural assembly. It fastens steel-to-steel structural connections where the application is critical.

 It is available both in Plain or Hot Dipped Galvanized finish, in the diameter range from 1/2" to 1 1/2".

 

A325 Structural Bolt  Dimensions

Bolt

Diameter

D

F

C

H

T

Body Diameter

Width Across Flats

Width Across Corners

Height

Thread Length

1/2

0.515

7/8

0.9895

5/16

1.00

5/8

0.642

1 1/16

1.201

25/64

1.25

3/4

0.768

1 1/4

1.413

15/32

1.38

7/8

0.895

1 7/16

1.6245

35/64

1.5

1

1.022

1 5/8

1.836

39/64

1.75

1 1/8

1.149

1 13/16

2.0475

11/16

2.00

1 1/4

1.277

2

2.259

25/32

2.00

1 3/8

1.404

2 3/16

2.471

27/32

2.25

1 1/2

1.531

2 3/8

2.682

15/16

2.25

 ** Some engineering drawing may show the bolts in the metric system, however they are only available in the imperial system, which mean the numbers must be converted into inches.

 

How to determine A325 Structural Bolt Length

If you are looking to determine the optimal length for your Structural Bolts on your project, 

You will need to calculate the sum of :

 Grip( Thickness of materials clamped together )    + Corresponding number on the table below ( Depending on number of F436 Washers used and bolt diameter )

  

Bolt Diameter

(inch)

Length to add (inch)

No Washer

One Washer

Two Washers

1/2

11/16

55/64

1 1/64

5/8

7/8

1 1/32

1 3/16

3/4

1

1 5/32

1 5/16

7/8

1 1/8

1 9/32

1 7/16

1

1 1/4

1 13/32

1 9/16

1 1/8

1 1/2

1 21/32

1 13/16

1 1/4

1 5/8

1 25/32

1 15/16

1 3/8

1 3/4

1 29/32

2 1/16

1 1/2

1 7/8

2 1/32

2 3/16

 

** In the case of a Beveled Washer being used,  add 5/16" to the 'No Washer' corresponding column.

 

E.G : If you are looking to clamp 2  Metal Frames of 3/8" thick each , using 3/4" diameter bolt assembled structural bolts with one washer. The length of the bolt would need to be (3/8" X 2) + 1 5/32" = 1.90625" rounding up on the size (increment by 1/4" inch) would give us 3/4" X 2" A325 Structural Bolts.

 

Have any question ?  Our professional team will gladly help you, you may send any inquiry at Boulonseclair@boulonseclair.com .

 

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