304 – Neoprene Rubber Polychloroprene (CR)

ASTM D-2000 classification: BC, BE


Temperature Range:

-40°C to +110°C (-40°F to +230°F).



Neoprene rubbers are homopolymers of chloroprene (chlorobutadiene) and were among the earliest synthetic rubbers used to produce seals. CR has good aging characteristics in ozone and weather environments, along with abrasion and flex cracking resistance. CR is not effective in aromatic and oxygenated solvent environments.

Most elastomers are either resistant to deterioration from exposure to petroleum based lubricants or oxygen, where Neoprene is unusual in having some resistance to both. This, combined with a broad temperature range and moderate cost, accounts for its desirability in applications with refrigerants like Ammonia, Freon® (R12, R13, R21, R22, R113, R114, R115, R134A), silicone oils, water, ozone, vegetable oils, alcohols, and low-pressure oxygen.

CR has a very low resistance to mineral oils.


EMI ReferenceSpecificationHardness IRHDSGTensile Strength (MPa)Elongation at Break %Colour
304 - CRC40BS2752:C4043°1.25136600Black
304 - CR501Commercial50°1.355400Black
304 - CRC50BS2752:C5053°1.3517480Black
304 - CR602Commercial60°1.456300Black
304 - CR601Commercial60°1.355300Black
304 - CR604Commercial60°1.456250Black
304 - CRC60BS2752:C6064°1.4219340Black
304 - CR606Food Quality 60°1.59450White
304 - CR607Insertion (reinforced)60°1.45--Black
304 - CR608Insertion (reinforced)60°1.355300Black
304 - CR701Commercial70°1.457250Black
304 - CRC70BS2752:C7073°1.418.9310Black
304 - CR709Flame Retardant (NCB)70°1.413400Black
304 - CRC80BS2752:C8083°1.419230Black

Full data sheets for all grades are available on request.

* The information above is supplied in good faith and believed to be correct. This information is supplied upon the condition that persons receiving this will make their own determination as to its suitability for their purposes prior to use. EMI makes no representations or warranties, either expressed or implied with respect to the information or the product to which this information refers.