O-rings are made to contain thousands of PSI pressure by creating a seal between two or more parts. O-ring measurements are specified by the inside diameter and the thickness.
Of the many causes for O-Ring failure, the most common among power tools are:
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Extrusion and Nibbling - O-ring has ragged, tattered edges. These
...Read more are commonly caused by pressure spikes which shear off tiny "bites" from the o-ring, or caused by clearance gaps.
• Abrasion - One or both sides of the o-ring appear rough and slightly flattened. Commonly caused by a contact surface that it too rough, contains grit or is too smooth to allow lubrication.
• Over Compression - O-ring is flattened on both sides and may have a "ring" split along its length. Commonly caused by excessive pressure or heat.
• Heat Hardening - O-ring has a pitted or cracked surface, and often is flattened on both sides. Caused by temperature exceeding o-ring capacity.
• Weather/Ozone Cracking - O-ring is covered in small surface cracks. Caused by exposure to ozone, UV rays and air pollution. Excessive seal stretching causes similar cracking.
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