Sterling SXS Series specifications Working on the Cutting Knives, Torque Grade Bolt type

Working on the Cutting Knives

Correctly setting and mounting the cutting knives is important when working with shredders to ensure efficient and economic function.

Replacing and Checking the Cutting Knife Mountings

Certain machine parts are subject to stress during operation as a result of vibrations that can lead to loosening of the screw connections. 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 knife fixing bolts is 355 Nm.

NOTE: You can find out the required torque from the following table. Tightening capacity decreases for screws when loosened and tightened again several times.

New screws of the same material quality must replace the cutting knife mounting screws after they have been loosened and tightened several times.

		Torque
					Grade 12.9
Bolt type	Grade 8.8		Grade 10.9
	Nm	lbf ft	Nm	lbf ft	Nm	lbf 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

Checking the Condition of the Cutters

WARNING! Danger of cutting caused by sharp knives at all times—even when rotor is at standstill. Serious Injury especially to the hands and fingers can occur. Wear protective gloves!

The cutting knives become blunt after a certain number of operation hours; they should be checked regularly. Using blunt knives 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.

BJ5-620 Maintenance 44 of 73