Overview of screw tightening torques

This overview shows only the most important screw connections.

Inner and outer cross head beams

Check the high-tensile bolts. The high-tensile bolts must meet these requirements:

	Material	Size	Lubrication
High-tensile bolt (hexagonal)	10.9 HV tZn	M20
Washer	C 45 HV tZn	HV 21	MoS2
High-tensile nut (hexagonal)	10 HV tZn	M20	MoS2

─ The high-tensile bolts and mounting plate with high-tensile nuts may only be installed with tightening torque a maximum of two times. If they are installed more than twice with tightening torque, the high-tensile bolts as well as the mounting plates with the high-tensile nuts must be scrapped.

Should it be necessary to loosen the high-tensile bolts during installation, the same high-tensile bolts can be reused a maximum of one more time, otherwise the lubrication will no longer be sufficient!

─ The high-tensile nuts and washers must be galvanised and lubricated with MoS2.

─ High-tensile bolts which have been installed on a crane for a lengthier period may not be used again.

	Central high-tensile bolt

Remaining high-tensile bolts

─ Only tighten high-tensile bolts with the appropriate torque wrench.

─ Do not use an impact wrench.

─ Do not tighten high-tensile bolts using turn-of-nut tightening.

Tighten the central high-tensile bolts on both sides (left and right on the cross head beam). Use a torque wrench to 300 Nm.

Next, tighten the remaining high-tensile bolts, alternating between left and right. Use a torque wrench to 300 Nm.

Then tighten all high-tensile bolts in the same sequence. Use a torque wrench to 450 Nm.

Note

Mark the high-tensile bolts with a permanent marker with a continuous line from the bolt head over the washer to the plate. This serves as proof that all high-tensile bolts have been tightened with tightening torque.