Chainsaw Bolt & Torque Specs
OEM-referenced torque specs and fastener sizes for chainsaws: Stihl MS 170/180, Husqvarna 120/130/135, and other Stihl and Husqvarna homeowner and mid-size saws. Covers bar mounting nuts, clutch cover nuts, and spark plugs. For Rancher-series bar nut torque by model, see the dedicated Husqvarna Chainsaw Torque page linked below.
Bar mounting nut torque
Bar mounting nuts on homeowner-class saws like the Stihl MS 170/180 and Husqvarna 120/130/135 torque to 15-20 ft-lb; larger Rancher-class saws (Husqvarna 455/460, Stihl MS 250) run 20-30 ft-lb. Tension the chain before final torque, and tighten the two bar nuts evenly in an alternating pattern so the bar seats flat against the clutch cover.
Clutch cover nut — left-hand thread
The clutch cover nut, or clutch drum nut on saws where it is exposed, commonly uses a left-hand thread: turn clockwise to loosen. This prevents the nut from backing off from the clutch drum spinning at high RPM during normal cutting. Forcing it counter-clockwise only tightens it further.
Spark plug torque scales with saw size
Spark plug torque on homeowner-class 2-stroke chainsaws like the Stihl MS 170/180 and Husqvarna 120/130/135 is light, around 6-7 ft-lb, because the aluminum cylinder head strips easily. Larger Rancher-class saws (Husqvarna 440-460) use a bigger plug thread and run higher, around 18-22 ft-lb. Always match torque to your saw plug size, not a generic 2-stroke value.
Related lookups
Loading interactive lookup…