Feature |
Name |
Symbol |
Cross Section |
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| A pressure ring with rectangular cross section. Most widely used in general applications. Has excellent performance in gas tightness and heat conduction. | Plain |
P |
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| The working surface is provided with a slight taper. Has excellent running-in performance at initial operation. | Taper face |
 |
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| The working surface is made slightly spherical to keep good contact with the cylinder wall even if the ring groove may be deformed due to operation temperature. Jamming and oil failure are thus effectively prevented. | Barrel tace |
 |
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Inside surface is beveled or cut to allow the ring to be inclined during operation. so that the ring working surface lower edge line contact with the cylinder wall to assist initial running-in. | Inside bevel |
 |
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Inside cut |
 |
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The lower edge of the working suriace is cut. While being a pressure ring, it also performs as an oil control ring. | Under cut |
 |
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| Gas and oil is effectively prevented from leaking through the ring-end gap, by providing a discontinued under cut as shown at the ring. | Effective seal |
 |
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| This is an undercut ring with tapered working surface, Has good fit to the cylinder wall and excellent oil control function. | Taper face under cut |
 |
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The cross section is wedge-shaped from both sides. Excellent in preventing ring sticking. | Both-side keystone |
 |
|
 |
The cross section is wedge-shaped from one side only. Excellent in preventing ring sticking. Two types of poston ring grooves are available as shown at the left. | Single-side Keystone |
 |
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A single-sidekeystone type is balanced to prevent ring sticking and to secure good contact with the lower suriace of the groove. It is therefore effective in gas sealing can be used in a rectangular ring groove. | S.G Keystone (Square-grooved keyston) |
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