CR (Neoprene)
A balanced rubber for general and outdoor use
Typical values for the temper in the title
CR (polychloroprene, trade name Neoprene) is the first synthetic rubber, developed by DuPont in 1930. It is balanced: moderate oil resistance, good weather and ozone resistance, resistance to flexing and aging, and flame retardant thanks to its chlorine.
It is not the best at any single property, but good at all of them, so it is common in seals and profiles in construction and outdoors, hoses, belts, padding and insulation, and wetsuits. Typical service range is from about -40 to about 100–120 °C.
Mechanical and physical properties
| Property | Value | Note |
|---|---|---|
| Max service temperature | ≈100–120°C | |
| Machinability | Molding / die-cut | relative rating in the site database |
Structure and family
| Feature | Value | Meaning |
|---|---|---|
| Type | polychloroprene | balance and flame retardance |
| ASTM D1418 code | CR | |
| Typical hardness | Shore A 40–90 | by compound |
Typical values per producer data.
Grades and versions
In rubber, the polymer type is chosen first (by fluid and temperature), then hardness (Shore A) and compound. In ASTM D2000 the code gives the service temperature (first letter) and oil resistance (second letter).
| Version | Properties | When to choose it |
|---|---|---|
| Solid sheet | seals and padding | cut gaskets |
| Sponge (closed cell) | insulation and padding | insulation, wetsuits |
| Profiles | outdoor sealing | windows, doors |
Applications
- Outdoor seals and profiles
- Hoses and belts
- Padding and insulation
- Flame-retardant parts
- Wetsuits
Fabrication
Suitable for
Weather and ozone (moderate to good), water, oils moderately, some refrigerants, dilute acids and bases.
Not suitable for
Aromatic and chlorinated solvents, ketones, oxidizing acids, fuels (limited resistance).
Production
Molding and curing (vulcanization), die-cutting from sheet, or extrusion. Machining rubber is not common.
Compared with similar materials
| Material | Rm / Rp0.2 | Welding | When it is the better choice |
|---|---|---|---|
| EPDM | 7-20 MPa | — | EPDM: more weather and steam resistant, not for oil · material page |
| NBR (Nitrile, Buna-N) | 15-25 MPa | — | NBR: more oil resistant, less weather resistant · material page |
| Silicone (VMQ) | 4-10 MPa | — | silicone: wider temperature range · material page |
Common mistakes
Choosing CR for oil or fuel service
NBR is more resistant.
Choosing CR for steam
EPDM is better.
Expecting FKM-like chemical resistance
Its resistance is moderate.
Equivalents, standards and supply
| ASTM | D1418: CR / D2000: BC, BE |
|---|---|
| Standards | ASTM D2000 BC/BE / ASTM D1418 |
| Forms | sheet · seal · hose · profile |
| Producers | Denka · Arlanxeo (Baypren) |
Learn more
Values are typical for a compound and for comparison only. In rubber, properties depend strongly on the compound (filler, cure, hardness). For seals, design to a chemical compatibility chart and producer data. Sources: ASTM D1418, ASTM D2000, ISO 1629, producer data, and the METAL HUB materials database.
Updated: October 31, 2026