Radial Seal
Compression is applied perpendicular to the seal centerline.
Reciprocating Seal
Seals used in moving piston and rod situations.
Reinforcing Agent
Fillers, such as Carbon Black, added to the elastomeric batch mix to improve such physical properties as tensile strength.
The capability of returning to original size and shape after deformation.
Rubber Manufacturers Association.
Root Mean Square. A measure of surface roughness typically applied to the machining of metal gland and shaft surfaces. RMS stands for the square root of the sum of the squares of micro-inch deviation from true flat.
Rotary Seal
Seals for rotating shafts, with the turning shaft protruding through the I.D. (hole) of the o-ring.
A common name for both naturally occurring and synthetically made elastomers.
Rubber, Natural
A natural product of the juices of certain tropical plants (latex), improved through heat treating with sulfur (vulcanization).
Rubber, Synthetic
Man-made elastomers such as Nitrile, Fluorocarbon, Silicone, etc.
Running Friction
A force which resists objects already in motion.
Runout (Shaft)
Same as gyration. When expressed in inches along, or accompanied by abbreviation “TIR” (total indicator reading), it refers to twice the radical distance between shaft axis and axis of rotation.