Universal Robots UR5 Service Manual page 28

CAUTION
Ensure the alignment taps are aligned before assembly. If the taps are
opposite each other (180 degree offset), the joints cannot be merged
properly and there is a risk the joint will loosen itself over time.
2. Make sure all washers are flush against the head of the bolt (this is important) before
gently twisting the parts clockwise roughly 5 degrees until a mechanical stop is met.
3. Gently tighten the screws, until they are almost in the correct position then tighten in cross
order (as shown in the numbered diagram below).
ALWAYS start with the screws at the alignment tap.
Tighten with the correct torque, to ensure that that the two faces are parallel.
See Torque values
UR5
for more information.
5. Service and Replacement of parts
22 Service Manual