Quick Answer
CSM emphasizes weather, ozone and chemical durability; NBR is a cost-effective oil-resistant workhorse. The choice depends on whether external environment or hydrocarbon contact is the dominant requirement.
CSM vs NBR: practical comparison
| Selection factor | CSM | NBR |
|---|---|---|
| Oil resistance | Good; compound dependent | Very good and widely used |
| Weather/ozone | Excellent | Limited without protection |
| Chemical/outdoor durability | Strong CSM use case | More limited outdoor durability |
| Cost | Specialty | Generally lower |
| Typical role | Exposed covers, chemical/outdoor components | Oil seals, hoses, hydraulic components |
How to choose
For an industrial hose, NBR may be attractive for the inner tube while CSM can be attractive for a weatherable/chemical-resistant outer cover.
Important: Ratings describe general polymer-family tendencies. Exact performance can change materially with grade, formulation, cure system, fluid composition, temperature and test method.
Frequently asked questions
Not automatically. NBR remains a strong oil-seal material; use CSM when other exposure requirements justify it.
Yes, multilayer designs can use different elastomers for different functions.