FEC AFC3000 - Page 196

Chapter 7 Fastening Instructions
PAGE 7-29
<Final Torque Check – Angle Control>
P For Angle Control operations, the Torque value may reach a peak value and then drop to a lower
value as the fastener is stretched beyond the point of yielding. Final Torque High and Low Limits are
either set by the engineering specification for that specific fastener or by determining the acceptable
limits from a study of known good and bad assemblies.
ANGLE CONTROL
REJECT TYPE
CAUSES
FINAL TORQUE HIGH LIMIT
Reduced joint compression.
Increased joint friction.
Excessive chatter of the torque signal due to slip stick friction.
Incorrect parameter set-up.
FINAL TORQUE LOW LIMIT
Increased joint compression.
Reduced joint friction.
Excessive yield of fastener or broken fastener.
High initial prevailing torque.
Incorrect parameter set-up.
Reject condition caused by another monitor item reject.
Peak Torque High Limit
Peak Torque Low Limit
Torque
Angle/Time
Final Torque High Limit
Final Torque Low Limit
Snug Torque
Ramp Down Start Torque
1
st
Torque
2
nd
Torque
2
nd
Time
1
st
Time
Standard
Angle