Tightening Torques - Stihl 021 Service & Repair Manual

3.6

Tightening Torques

DG screws are used in the polymer and light-alloy components. These screws form a permanent thread
when they are installed for the first time. They can be removed and installed as often as necessary without
detrimentally affecting the strength of the screwed assembly, providing the specified tightening torque is
observed. For this reason it is essential to use a torque wrench.
Fastener Thread
Spline screw IS-DG4x15
Spline screw IS-DG4x15
Spline screw IS-DG4x15
Spline screw IS-DG4x15
Spline screw IS-DG5x24
Spline screw IS-DG5x24
Spline screw IS-DG5x24
Spline screw IS-DG5x24
Spline screw IS-DG5x24
Spline screw IS-DG5x24
Spline screw IS-DG5x24
Spline screw IS-DG5.3x40
Collar screw DG8x18
Collar screw (rear) DG8x18
M12x1L
M14x1.25
Hexagon nut M5
Hexagon nut M5
Collar nut M8x1
M12x1.5
Slotted nut M5
Spline screw IS-DG5x16
Use the following procedure to fit a DG screw in an existing thread:
– Place the DG screw in the hole and rotate it counterclockwise until drops down slightly.
– Tighten the screw clockwise to the specified torque.
This procedure ensures that the screw engages properly in the existing thread and does not form a new thread,
which would weaken the assembly.
1) 023 L
2) On easy start version only
3) With quick chain adjuster
Note: Power screwdriver speed settings for polymer: Plastoform screws
021, 023, 025
For component
size
Chain brake cover
Handle molding
Connector
(engine/oil pump)
Ground wire
(to cylinder)
Handle housing/
front handle
Hand guard
Hand guard
Fan housing
Buffer (to front handle)
Buffer (to engine)
Ignition module
(to engine housing)
Cylinder
(to engine housing)
Guide bar mounting
Guide bar mounting
Carrier (clutch)
Spark plug
Muffler
Filter housing/carburetor
Flywheel to crankshaft
Decompression valve
Filter base/carburetor
Spiked bumper
DG screws
Torque Remarks
Nm lbf.ft
2.0 1.5
1.6 1.2
2.5 1.8
3.5 2.6
3.5 2.6
3.5 2.6
3.7 2.8 1)
3.5 2.6
3.5 2.6
3.5 2.6
4.0 3.0
9.5 7.0
16.0 11.8
8.0 5.9 3)
50.0 37.0
25.0 18.5
7.0 5.2
2.7 2.0
28.0 21.0
14.0 10.3 2)
2.0 1.5 1)
3.7 2.8
max. 600 rpm
max. 500 rpm
5