Sterlco SMS Series Single Shaft Shredder - Manual (Page 48)

GRN4-605 Chapter 5: Maintenance 48 of 93
Replacing and Checking the Cutting Cutter Mountings
Certain machine parts are subject to stress during operation as a result of vibrations that
can lead to loosening of the screw connections. Therefore, it is absolutely necessary to
check the cutter and bed knife mounting screws in accordance with the Maintenance
Plan.
1. Tighten the mounting screws on the cutters and bed knives using a torque wrench.
(Check required torque for the screw size.) The required torque for the cutter
mounting screws is 120 Nm.
NOTE: You can find out the required torque from the following table. Tightening
capacity decreases for screw when loosened and tightened again several times.
New screws of the same material quality must replace the cutting cutter
mounting screws after they have been loosened and tightened several times.
Checking the Condition of the Cutters
Danger of cutting caused by sharp cutters at all times—even when rotor is
at standstill. Serious Injury especially to the hands and fingers can occur.
Wear protective gloves!
The cutting cutters become blunt after a certain number of operation hours; they should be
checked regularly. Using blunt cutters can affect the efficiency and performance of the
machine in the following ways:
• Decreased shredding capacity.
• Increased current consumption of the drive motor.
• Inexact cut.
• Overheating of the shredded material.
Dismounting the Cutters (see drawing below)
1. Switch OFF the shredder at the main switch.
Torque
Screw type Grade 8.8 Grade 10.9 Grade 12.9
Nm lb. ft Nm lb. ft Nm lb. ft
M8 25 18.4 35 25.8 41 30.2
M10 49 36.1 69 50.9 83 61.2
M12 86 63.4 120 88.5 145 106
M16 210 154 295 217 355 261
M20 410 302 580 428 690 508
M24 710 523 1000 737 1200 885