Common Name	ASTM Designation D 1418-93	Composition	General Properties
Natural	NR	Isoprene Rubber (Natural)	Excellent physical properties,including abrasion resistance.Not oil resistant
SBR	SBR	Styrene-Butadiene Rubber	Good pysical properties,includingabrasion resistance.Not oil cresistant
EPM or EPDM	EPOM	Elthylene-Propylene-diene-terpolymer	Good general purpose polymer.Excellent heat,ozone and weather resistance. Not oil resistant
Neoprene	CR	Chloroprene	Excellent weathering resistance. Flame retarding.Good oil resistance.Good pysical properties
Bruna-N or Nitrile	NBR	Nitrile-Butadiene	Excellent oil resistance. Good pysical properties
Hypalon	CSM	Chloro-sulfonated polyetylene	Excellent ozone,weathering and acid resistance.Good abrasion and heat resistance. Can be compounded for good oil resistance
Cholorinated polyethylene (CPE)	CM	Chloro-polyetilene	Good long term resistance to UV and weathering. Good oil and chemical resistance. Excellent flame resistance Good low temperature impact resistance.
Cross Linked Polyethylene	XLPE	Cross Linked Polyetylene	Excellent resistance to most solvents,oil,and chemicals. Do not confuse with chemical properties of standard polyetylene
Butyl	IIR	Isobutene-isoprene	Very good weathering resistance, low permeability to air. Good physical properties. Poor resistance to petroleum based fluids.
Viton	FKM	Fluorocarbon rubber	Excellent high temperature resistance, particulary in air or oil. Very good chemical resistance