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  • 17x40x8mm Nitrile Rubber Rotary Shaft Oil Seal with Garter Spring R21 / SC
  • 17x40x8mm Nitrile Rubber Rotary Shaft Oil Seal with Garter Spring R21 / SC
17x40x8mm Nitrile Rubber Rotary Shaft Oil Seal with Garter Spring R21 / SC
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17x40x8mm Nitrile Rubber Rotary Shaft Oil Seal with Garter Spring R21 / SC

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Oil Seals: Designed to aid trouble-free operation of your equipment, providing an excellent barrier against the escape of oils and greases and preventing the ingress of foreign matter.
Benefits: Excellent wear resistance, good running properties, high resistance to chemicals and petroleum based fuels including petrol, diesel and LPG.

Brand / Quality: Simply NBR Seals - High Quality
Inside Diameter: 17mm
Outside Diameter: 40mm
Width: 8mm
Shaft Size not Inside Diameter (d)
Outside Diameter (D)
Width (b)
Oil Seals
An oil seal normally consists of three basic components: The Sealing Element (the nitrile rubber part), the Metal Case, and the Spring. It is a widely used sealing component. The function of a seal is to prevent the leakage of medium along the moving parts. This is mainly achieved by the sealing element. Nitrile Rubber (NBR)
NBR is the most commonly used seal material. It has good heat resistance properties, good resistance to oils, salt solutions, hydraulic oils, and gasoline. Operation temperatures are recommended from -40deg C to 120deg C. It also functions well under dry environment, but only for intermittent periods.
R21 / SC design cross section

Cross section of an R21 / SC style oil seal.

This is a single sealing lip seal arrangement.

The seal cases are made from SAE 1008-1010 Carbon Steel and are often coated in a very thin layer of Nitrile rubber to assist sealing in the housing.
The principle function of the metal case is to impart rigidity and strength to the seal.
The spring is made from SAE 1050-1095 Carbon Spring Steel which has a protective zinc coating.
The principle function of the spring is to maintain an even gripping pressure around the shaft

Viton Chemical Resistance

  • Ashton Villegas, United Kingdom 19/12/2019

    5 of 5 Stars!
    I called at your trade counter to source some replacement oil seals which were very badly damaged . Although they were extremely distorted the young lady was very methodical and thorough in identifying the correct replacements but above all she was polite and patient. A very good experience indeed.

  • Kamari Killian, United Kingdom 30/09/2019

    5 of 5 Stars!
    Thanks for delivering my oil seals the next day

  • Leandro Seth, United Kingdom 30/09/2019

    5 of 5 Stars!
    Great selection of oil seals and I found what I needed in no time at all. Top quality and great value.

  • Aaron Yahir, United Kingdom 08/03/2018

    5 of 5 Stars!
    great quality seal at very affordable prices

  • Yusuf Lamont, United Kingdom 18/02/2016

    5 of 5 Stars!
    service is always second to none

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17x40x8mm Nitrile Rubber Rotary Shaft Oil Seal with Garter Spring R21 / SC

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Simply bearings are the UK's largest online retailer of bearings, seals, belts, chains, sprockets, lubricants and other associated power transmission equipment.
Simply Bearings Ltd, Halton House, Greenfold Way, Leigh
Greater Manchester
United kingdom

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