CSM
also Hypalon
CSM (Hypalon) is a chlorosulfonated polyethylene elastomer cured with an MgO acid acceptor plus a sulfur donor or peroxide.
Reference datasheet — CSM is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the GP-A70 condition
CSM grades and fills
CSM is supplied in 10 conditions, soft to hard. GP-A70 is the default FabDigit quotes; the values on this page are for it.
Compare all 10 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Solution / coating & adhesive grade | Low-Mooney polymer dissolved in aromatic/chlorinated solvent for tank linings, corrosion-protective and marine paints. | 8 | 300 | 15 Shore D | |
Roofing / pond-liner membrane sheet | Reinforced or unreinforced calendered sheet for single-ply roofing and containment liners with 20+ year weathering. | 9 | 300 | 21 Shore D | |
Soft compound, Shore A 50 | Choose for low-closure-force seals, diaphragms and flexible sheet where softness matters more than strength. | 10 | 480 | 50 Shore A | |
Flame-retardant compound | Specify where UL 94 V-0 or low-flame-spread jacketing/sheeting is mandated. | 11 | 280 | 27 Shore D | |
White / light-colored weathering grade | Pick when colored, non-blooming outdoor parts are needed — CSM keeps color and gloss without carbon black. | 12 | 380 | 20 Shore D | |
Cable jacket / electrical grade | Use for flexible cord and mining/welding cable jackets requiring heat, ozone and flame resistance. | 14 | 350 | 75 Shore A | |
GP-A70Default General purpose, Shore A 70 | Default weather-resistant compound for hose covers, gaskets, rollers and molded goods. | 16 | 320 | 22 Shore D | |
High-chlorine (≈40–43% Cl) oil/chemical-resistant grade | Higher chlorine content improves oil, fuel and chemical resistance at the cost of low-temperature flexibility. | 17 | 300 | 72 Shore A | |
Low-chlorine, low-temperature flexible grade | Choose when cold flexibility to about −45 °C matters more than oil resistance. | 18 | 420 | 17 Shore D | |
Hard compound, Shore A 80–90 | For rolls, wear liners and extruded profiles needing higher modulus and abrasion resistance. | 20 | 220 | 30 Shore D |
What is CSM?
CSM (Hypalon) is a chlorosulfonated polyethylene elastomer cured with an MgO acid acceptor plus a sulfur donor or peroxide. It combines ozone, weathering and chemical resistance with the ability to make light-coloured, non-blooming compounds, at about 1.35 g/cm³ density, 16 MPa tensile strength, 320 % elongation and 125 °C maximum service temperature. Typical forms are calendered roofing membrane, cable jacket, moulded fenders and solution grades for coatings. It is scorch-sensitive and tacky to process, fuel and aromatic resistance is limited, and availability is narrower than EPDM or CR. CSM has a density of 1.35 g/cm³ (0.0488 lb/in³), heavier than 75% of polymer grades. Its glass-transition temperature is -25°C (-13 °F). CSM has a tensile strength of 16 MPa (2.32 ksi), weaker than 72% of polymer grades. Elongation at break is 320% and the elastic modulus is 0.01 GPa (0.001 Msi).
What is CSM used for?
- roofing membranes
- boat fenders
- cable jacketing
- chemical-resistant coatings
Advantages
- Good UV / weathering resistance — 95/100, better than 95% of polymer grades
- Ductile — tolerates forming and impact — 320%, better than 82% of polymer grades
- Forms and bends easily — 85/100, better than 81% of polymer grades
Limitations
- High mold shrinkage — 2.5%, worse than 93% of polymer grades
- Low stiffness — 0.01 GPa (0.001 Msi), worse than 84% of polymer grades
- Difficult to machine — 35/100, worse than 84% of polymer grades
- Heavy — 1.35 g/cm³ (0.0488 lb/in³), worse than 75% of polymer grades
- Absorbs moisture — dry before molding — 0.6%, worse than 75% of polymer grades
CSM properties
Typical room-temperature values for CSM-GP-A70; bars are the position among polymer grades.
Physical3
CSM has a density of 1.35 g/cm³ (0.0488 lb/in³), heavier than 75% of polymer grades. Its glass-transition temperature is -25°C (-13 °F).
Mechanical8
CSM has a tensile strength of 16 MPa (2.32 ksi), weaker than 72% of polymer grades. Elongation at break is 320% and the elastic modulus is 0.01 GPa (0.001 Msi).
Thermal8
CSM is rated for continuous service to 125°C (257 °F). It conducts heat at 0.2 W/m·K (0.116 BTU/hr·ft·°F), worse than 56% of polymer grades. Thermal expansion is 180 µm/m·K (100 µin/in·°F).
Electrical5
CSM is an electrical insulator with a dielectric strength of 22 kV/mm (558.8 V/mil) and a resistivity of 1×10¹¹ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (85/100), better than 65% of polymer grades. UV resistance is excellent.
Sustainability3
Producing a kilogram of CSM takes about 105 MJ of energy and emits 4.5 kg of CO₂ — more than 54% of polymer grades. Typical recycled content is 0%.
Manufacturability6
CSM's machinability is fair (35/100, worse than 84% of polymer grades); weldability good (65/100); formability excellent (85/100).
Common Calculations4
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the polymer family
Yield strength against density for every polymer grade FabDigit runs. CSM is highlighted; hover a dot for its name, or open the interactive family chart.
Working with CSM
Is CSM easy to machine?
Die-cutting, water-jet and cryogenic trimming preferred; conventional machining smears — use sharp blades and lubricant for skiving rolls.
Can CSM be welded?
Cured stock is not weldable; uncured or non-cured-membrane sheet is joined by solvent (toluene/xylene) or hot-air seaming and by CSM-based contact adhesives after abrasion.
Can CSM be formed, bent or molded?
Mixes on cold mill or internal mixer below ~110 °C to avoid scorch; calenders and extrudes well but is tacky — needs release/anti-tack dusting; press cure 150–180 °C with MgO acid acceptor plus sulfur-donor or peroxide cure system.
CSM chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| chlorosulfonated polyethylene polymerbase polymer; chlorine 24–43 wt%, sulfur (as sulfonyl chloride) 0.8–1.5 wt% of polymer | 35 – 60 | 45 |
| chlorine (in polymer)on polymer basis, not compound | 24 – 43 | 35 |
| sulfur (sulfonyl)on polymer basis; provides cure sites | 0.8 – 1.5 | 1.1 |
| carbon black / mineral fillerN550/N774 or TiO₂+clay in light colors | 20 – 45 | 33 |
| plasticizer / process oilchlorinated paraffin, ester or aromatic plasticizer | 3 – 15 | 8 |
| MgO / litharge / epoxy acid acceptoressential HCl scavenger for heat aging | 2 – 8 | 4 |
| cure system (sulfur donor, MBTS/TMTD or peroxide cure gives best heat resistance | 1 – 5 | 3 |
| compound balance (antioxidant, wax, pigm | balance |
What surface finishes work on CSM?
Accepts CSM/acrylic paints and pigmenting without blooming; bonds to metal with chlorinated-rubber or phenolic primers; surface can be chlorinated/primed for adhesive lamination.
Equivalent designations
Standards and trade names that resolve to CSM in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- Hypalon
How much does CSM cost?
CSM is a premium-cost polymer ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
CSM — frequently asked
What is CSM used for?
CSM is typically used for roofing membranes, boat fenders, cable jacketing and chemical-resistant coatings. In short: ozone and weather resistant; light-colour non-blooming compounds; chemical-resistant coating base.
What is the tensile strength of CSM?
CSM has a typical tensile strength of 16 MPa (2.32 ksi) — weaker than 72% of polymer grades. Strength varies by condition: see the 10 listed tempers.
Is CSM easy to machine?
Not especially — machinability is rated fair (35/100, worse than 84% of polymer grades). Die-cutting, water-jet and cryogenic trimming preferred; conventional machining smears — use sharp blades and lubricant for skiving rolls.
Can CSM be welded?
Yes — weldability is rated good (65/100). Cured stock is not weldable; uncured or non-cured-membrane sheet is joined by solvent (toluene/xylene) or hot-air seaming and by CSM-based contact adhesives after abrasion.
What surface finishes work on CSM?
Accepts CSM/acrylic paints and pigmenting without blooming; bonds to metal with chlorinated-rubber or phenolic primers; surface can be chlorinated/primed for adhesive lamination.
Can CSM be formed, bent or molded?
Mixes on cold mill or internal mixer below ~110 °C to avoid scorch; calenders and extrudes well but is tacky — needs release/anti-tack dusting; press cure 150–180 °C with MgO acid acceptor plus sulfur-donor or peroxide cure system.
What is the maximum service temperature of CSM?
CSM is rated for continuous use to about 125°C (257 °F), and briefly to 165°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does CSM cost?
CSM is a premium-cost polymer ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- TOSO-CSM Chlorosulfonated Polyethylene technical bulletin — Tosoh Corporation (2022)
- Hypalon Synthetic Rubber — Properties and Compounding Guide (legacy) — DuPont Performance Elastomers (2008)
- Engineered Materials Handbook Vol. 2: Engineering Plastics / Elastomers data — ASM International (1999)
- ASTM D2000 — Classification System for Rubber Products in Automotive Applications (CE/CH type-class) — ASTM (2018)
- GB/T 5576 (CSM designation) — SAC / (1997)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.