Oregon Harvester Handbook page 15

Manual Tensioning Systems
• Saw chain should be tight enough to pull the chassis of the
saw chain firmly against the perimeter of the guide bar .
• Tension needs to be checked regularly .
• Only tension saw chain when it is cool . Steel expands
when hot and contracts as it cools . As a result, it could
cause damage to your guide bar or saw motor if tensioned
when hot .
• At shut down or breaks, relieve saw chain tension to prevent
damage to the cutting system (saw motor, bar tip, saw chain
chassis) as the saw chain cools and contracts .
• In cold weather, maintain proper tension . Check tension often
with manual tensioning systems .
Checking Tension
To check for proper tension, grasp the saw chain at the mid-span
of the guide bar and pull the saw chain away from the bar rails .
• For hard nose guide bars, the drive link tangs should nearly
come out of the bar groove .
• For sprocket nose guide bars, the saw chain chassis
should come out of the bar groove/away from the bar
rails approximately 1/8 inch ( approximately 3 mm) . When
released, the chassis should snap back against the bar rails .
Operational Recommendations
Mechanical Timber Harvesting Handbook
1/8"
10