Page 262 - HAZET英文2021

Torque Technology

Increased screw connection quality through

improvement in the screw tightening

Torque + Rotation angle
sTAC controlled tightening process
Accuracy / Precision of the screw connection ➧ ➧ ➧ ➧ ➧ ➧ 6000 CT Torque controlled

sTAC

tightening process

5000 CT

tightening process,
not monitored
Impact wrench Machine-operated
Manually operated
tightening process,
not monitored
Wrenches

The complete screw connection is only OK if the
torque and rotation angle are both OK (Fig. c)

a b c

Torque Torque Torque

Torque O K. Rotation Torque not OK. Rotation Torque O K Rotation
Rotation angle not OK. angle Rotation angle O K. angle Rotation angle O K. angle
Important: In particular for the joints using threaded fasteners of the category A (according to VDI guideline 2862),
e.g. belt, airbag or rotor blades for wind energy plants!
Figure 1: Figure 2:
The torque is reached, but the rotation The rotation angle is reached, but the
angle isn’t. – Possible causes: torque isn’t. – Possible causes:
• Use of an incorrect screw that is too long. • Use of an incorrect screw that is too short
and the thread has been ripped out.
• The component to be screwed is too thin, screw
or nut is stuck in the end of the thread. • Use of an incorrect screw with insufficient strength.
• The head and / or thread friction are too high because • The head and / or thread friction are too low
the surfaces are too rough and the screw has possibly because the screw coating is incorrect.
“jammed”, for example. The coating of the screw is not • Use of an incorrect screw.
correct because a screw with a different coating was
used or the coating is incomplete. There is not sufficient • Use of an incorrect lubricant.
lubrication or an incorrect lubricant has been used. • The screw or the thread is damaged or
• Screw or thread is damaged. the thread has been ripped out.
• Thread is incorrectly cut and not deep enough. • Installation of an incorrect seal that is too soft.
• There are chips from the thread cutting in the blind hole.
• A washer or a seal has been forgotten
and the screw is in place.

Components and spare parts from page 482 to 490 Valid until December 31, 2021 261