Torque Calculator

 

Calculation according to DIN946 (Rotzler formula) when using NORD-LOCK washers Bolt size

A

Thread pitch [mm] B

Mean diam. of thread [mm]

Load area [mm2]

0.0

0.00

M

Thread friction

µT C

OD of contact area [mm] D

ID o f contact area [mm] E

Mean diam. of contact area

Washer friction

µW F

Yield point of bolt [Mpa] G

0.00

= specify parameters A B C D

Specify bolt size (Metric only) Specify tread pitch Specify thread friction (if possible please use chart 1 below) OD of contactact area = outer diameter of contact area between NL washer and nut/bolt head

E F G H

ID of contactact area = inner diameter of contact area between NL washer and nut/bolt head Specify washer friction (if possible use chart 1 below) Specify yield point of bolt (if possible use chart 2 below) Specify ratio of the bolt's yield point (%)

Chart 1: Thread friction µT and Washer friction µW (according to DIN946) Bolt grade

Non Lubricated Thread Washer

With oil spray Thread Washer

With MoS2 Thread Washer  

8.8

0 .1 5

0 .1 7

0 .1 2

0 .1 4

0 .1 1

0 .1 2

10.9

-

-

0 .1 4

0 .1 1

0 .1 4

0 .1 0

12.9

-

-

0 .1 4

0 .1 1

0 .1 5

0 .1 0

 A4

-

-

-

-

0 .1 4

0 .1 5

Chart 2: Yield points for most common bolt grades Bolt grade

3.6

4 .6

4 .8

5 .6

Steel 5 .8

6.8

8 .8

9.8

 Yield point [Mpa]

1 80

240

320

3 00

40 0

4 80

6 40

72 0

 

Ratio of Tension yield point [%] [Mpa]

Clamp load [kN]

Tightening torque [Nm]

H 0

0.0

0.0

Stainless steel 10.9

12.9

A4-50

A4-70

A4-80

900

1080

210

450

600