O-Rings
| Product name | O-Rings/P Series |
| Part number | NPA32 |
* Orange colored cells in the table below indicate the part numbers used in this example.
Selection criteria
To transport a workpiece without damaging it
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Available sizes
■O-Rings - P Series
| Material | Hardness (JIS Hs) | Color | Operable Temperature Range | JIS Symbol | Usage |
| Nitrile Rubber | 70±5 | Black | -30-100°C | Class 1 A | Mineral Oil Resistant |
| 90±5 | Black | -25-100°C | Class 1 B |
| Silicon Rubber | 50±5 | Milky White | -50-200°C | - | Heat Resistant |
| 70±5 | Navy | -50-200°C | Class 4 C |
| Fluororubber | 70±5 | Black | -15-200°C | Class 4 D |
| 90±5 | Black | -15-200°C | - |
Ethylene Propylene Rubber | 70±5 | Black | -45-130°C | - | Weather Resistant |
■Sizes and Dimensions (excerpt)
JIS Nominal Number | Ring I.D. | Ring Wire Dia. | Mating Side Dia. Against O-ring |
| Internal Contact | External Contact |
| P22 | Ø21.8 | Ø2.4 | Ø22 | Ø26 |
| P22A | Ø21.7 | Ø3.5 | Ø22 | Ø28 |
| P22.4 | Ø22.1 | Ø22.4 | Ø28.4 |
| P24 | Ø23.7 | Ø24 | Ø30 |
| P25 | Ø24.7 | Ø25 | Ø31 |
| P25.5 | Ø25.2 | Ø25.5 | Ø31.5 |
| P26 | Ø25.7 | Ø26 | Ø32 |
| P28 | Ø27.7 | Ø28 | Ø34 |
| P29 | Ø28.7 | Ø29 | Ø35 |
| P29.5 | Ø29.2 | Ø29.5 | Ø35.5 |
| P30 | Ø29.7 | Ø30 | Ø36 |
| P31 | Ø30.7 | Ø31 | Ø37 |
| P31.5 | Ø31.2 | Ø31.5 | Ø37.5 |
| P32 | Ø31.7 | Ø32 | Ø38 |
| P34 | Ø33.7 | Ø34 | Ø40 |
| P35 | Ø34.7 | Ø35 | Ø41 |
| P35.5 | Ø35.2 | Ø35.5 | Ø41.5 |
| P36 | Ø35.7 | Ø36 | Ø42 |
| P38 | Ø37.7 | Ø38 | Ø44 |
| P39 | Ø38.7 | Ø39 | Ø45 |
| P40 | Ø39.7 | Ø40 | Ø46 |
| P41 | Ø40.7 | Ø41 | Ø47 |
| P42 | Ø41.7 | Ø42 | Ø48 |
| P44 | Ø43.7 | Ø44 | Ø50 |
| P45 | Ø44.7 | Ø45 | Ø51 |
| P46 | Ø45.7 | Ø46 | Ø52 |
| P48 | Ø47.7 | Ø48 | Ø54 |
| P50 | Ø49.7 | Ø50 | Ø56 |
* Please see the product pages for other diameter rings.
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Accuracy Info
Ring Wire DIA. Tolerance:
| Wire Dia. | Tolerance |
| Ø1.9 | ±0.08 |
| Ø2.4 | ±0.09 |
| Ø3.5 | ±0.10 |
| Ø5.7 | ±0.13 |
Parting Surface Burr Height: 0.1 or less
Parting Surface Burr Width: 0.15 or less
Ring I.D. Tolerance;
JIS Nominal Number | Ring I.D. | Tolerance |
| Nitrile | Silicone Ethylene | Fluorine |
| P22 | Ø21.8 | ±0.24 | ±0.36 | ±0.28 |
| P22A | Ø21.7 |
| P22.4 | Ø22.1 |
| P24 | Ø23.7 |
| P25 | Ø24.7 | ±0.25 | ±0.37 | ±0.30 |
| P25.5 | Ø25.2 |
| P26 | Ø25.7 | ±0.26 | ±0.39 | ±0.31 |
| P28 | Ø27.7 | ±0.28 | ±0.42 | ±0.33 |
| P29 | Ø28.7 | ±0.29 | ±0.43 | ±0.34 |
| P29.5 | Ø29.2 |
| P30 | Ø29.7 |
| P31 | Ø30.7 | ±0.30 | ±0.45 | ±0.36 |
| P31.5 | Ø31.2 | ±0.31 | ±0.46 | ±0.37 |
| P32 | Ø31.7 |
| P34 | Ø33.7 | ±0.33 | ±0.49 | ±0.39 |
| P35 | Ø34.7 | ±0.34 | ±0.51 | ±0.40 |
| P35.5 | Ø35.2 |
| P36 | Ø35.7 |
| P38 | Ø37.7 | ±0.37 | ±0.55 | ±0.44 |
| P39 | Ø38.7 |
| P40 | Ø39.7 |
| P41 | Ø40.7 | ±0.38 | ±0.57 | ±0.45 |
| P42 | Ø41.7 | ±0.39 | ±0.58 | ±0.48 |
| P44 | Ø43.7 | ±0.41 | ±0.61 | ±0.49 |
| P45 | Ø44.7 |
| P46 | Ø45.7 | ±0.42 | ±0.63 | ±0.50 |
| P48 | Ø47.7 | ±0.44 | ±0.66 | ±0.52 |
| P50 | Ø49.7 | ±0.45 | ±0.67 | ±0.54 |
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Idler Pulleys
| Product name | Idler Pulleys/Resin/Flat/Flanged |
| Part number | TPBSN38-15 |
| Features | Can be used as the tension adjuster for timing belts. |
* Orange colored cells in the table below indicate the part numbers used in this example.
Selection criteria
Used for tension adjustment of a timing belt
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Available sizes
■Idler Pulleys - Resin, Flat / Flanged
| Body Material | Bearing Material |
Glass Reinforced Nylon (engineered plastic) | Steel |
■Sizes
Nominal Dia. of the Idler | Overall Width | Inner Width | O.D. | Bearing No. to Use | Applicable Idler Shaft |
| Flanged | No Flange | Flanged |
| Ø38 | 18 | 18 | 15 | Ø42 | 6200ZZ | WS010S |
| Ø40 | 26 | 26 | 20 | Ø48 | 6201ZZ | WS116S ・ WS122S |
| Ø45 | 25 | 25 | Ø50 | 6202ZZ | WS216S |
| Ø46 | Ø52 | 6201ZZ | WS112S ・ WS116S |
| Ø50 | 31 | 31 | 25 | Ø62 | WS116S ・ WS122S |
| Ø60 | 36 | - | 30 | Ø66 |
| Ø70 | 35 | - | 28 | Ø80 | 6202ZZ | WS216S ・ WS222S |
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IDEA NOTE Circuit board contact
An O-ring is used on the roller for contacting the sides and edges of the circuit board.
IDEA NOTE Rollers serve as a width guide
The roller attached with the O-ring is flanged and the flange guides the workpiece in the widthwise direction.
IDEA NOTE Idler
Idler presses the belt from the top, creating proper tensioning between belt and pulleys.