Click and Collect now available during checkout.

Close X

Price Breaks




£1.49 each


£1.40 each


£1.39 each


£1.37 each


£1.35 each


£1.34 each


£1.25 each


£1.24 each


£1.22 each


£1.20 each


£1.17 each

  • 16x30x4.5mm Nitrile Rubber Rotary Shaft Oil Seal R21 / SC
  • 16x30x4.5mm Nitrile Rubber Rotary Shaft Oil Seal R21 / SC
16x30x4.5mm Nitrile Rubber Rotary Shaft Oil Seal R21 / SC
Great rates on shipping on any order regardless of size

Add to a Save List

Share this product with Friends or Colleagues

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: 16mm
Outside Diameter: 30mm
Width: 4.5mm
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

  • Rodolfo Bray, United Kingdom 19/12/2019

    5 of 5 Stars!
    The whole order process of my oil seals was easy and quick.

  • Reece Dougherty, United Kingdom 19/12/2019

    5 of 5 Stars!
    Brilliant attitude over the telephone. Clear, concise and confident in the oil seals they sold to me.

  • Aarav Giovanni, United Kingdom 18/12/2019

    5 of 5 Stars!
    Thank you for helping me find the correct oil seals.

  • Riley Juan, United Kingdom 27/09/2019

    4 of 5 Stars!
    Thanks for getting my oil seals to me so quickly. Brilliant service.

  • Marvin Dax, United Kingdom 08/09/2015

    5 of 5 Stars!
    would like to say what outstanding service you have everything was bob on cheers

View More

Write a Product Review

16x30x4.5mm Nitrile Rubber Rotary Shaft Oil Seal R21 / SC

Please rate and write your honest review of this item in up to 300 characters:

* Required Fields *


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

The product has been added to your saved list.