CPVC IM
Grade
ISO 1043 PVC-C · also Corzan, Chlorinated PVC
IM = impact-modified CPVC compound
Choose where installation abuse or sub-ambient handling causes brittle cracking; trades some stiffness and HDT for toughness.
Values for the IM condition
Other CPVC grades and fills
CPVC is listed in 4 conditions; see the grade overview at CPVC.
Compare all 4 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Cellular (foam-core) CPVC sheet / pipe | Use where weight, insulation or cost per area matters and pressure rating is not required (duct, non-pressure sheet, foam-core pipe). | 23 | 25 | 12 | 68 Shore D |
IMThis page Impact-modified CPVC compound | Choose where installation abuse or sub-ambient handling causes brittle cracking; trades some stiffness and HDT for toughness. | 44 | 48 | 50 | 78 Shore D |
ASTM D1784 pressure-pipe cell class | Pick for potable hot/cold water, fire sprinkler and industrial pressure piping where D1784 cell-class minimums must be met. | 52 | 55 | 25 | 82 Shore D |
20% glass-fiber reinforced CPVC | For structural fittings, valve bodies and duct components needing higher stiffness and lower creep/CTE at temperature. | 75 | 2.5 |
What is CPVC IM?
CPVC IM is CPVC in the IM grade — choose where installation abuse or sub-ambient handling causes brittle cracking; trades some stiffness and HDT for toughness. CPVC IM has a yield strength of 44 MPa (6.38 ksi) and a tensile strength of 48 MPa (6.96 ksi) — weaker than 60% of polymer grades. Elongation at break is 50% and the elastic modulus is 2.5 GPa (0.363 Msi). CPVC IM has a density of 1.54 g/cm³ (0.0556 lb/in³), heavier than 90% of polymer grades. Its glass-transition temperature is 115°C (239 °F).
Advantages
- Low moisture uptake — 0.04%, better than 86% of polymer grades
- Low embodied carbon — 3 kg CO₂/kg, better than 83% of polymer grades
- Easy to machine — 78/100, better than 81% of polymer grades
- Good UV / weathering resistance — 55/100, better than 77% of polymer grades
Limitations
- Heavy — 1.54 g/cm³ (0.0556 lb/in³), worse than 90% of polymer grades
- Poor heat conductor — 0.15 W/m·K (0.0867 BTU/hr·ft·°F), worse than 80% of polymer grades
CPVC IM properties
Typical room-temperature values for CPVC IM; 24 are specific to this condition. Other listed values are CPVC reference data and may not represent this condition. Bars are the position among polymer grades.
Physical5
CPVC IM has a density of 1.54 g/cm³ (0.0556 lb/in³), heavier than 90% of polymer grades. Its glass-transition temperature is 115°C (239 °F).
Mechanical14
CPVC IM has a yield strength of 44 MPa (6.38 ksi) and a tensile strength of 48 MPa (6.96 ksi) — weaker than 60% of polymer grades. Elongation at break is 50% and the elastic modulus is 2.5 GPa (0.363 Msi).
Thermal11
CPVC IM is rated for continuous service to 88°C (190 °F). It conducts heat at 0.15 W/m·K (0.0867 BTU/hr·ft·°F), worse than 80% of polymer grades. Thermal expansion is 68 µm/m·K (37.8 µin/in·°F).
Electrical6
CPVC IM is an electrical insulator with a dielectric strength of 22 kV/mm (558.8 V/mil) and a resistivity of 1×10¹³ Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (80/100), worse than 52% of polymer grades. UV resistance is good.
Sustainability4
Producing a kilogram of CPVC IM takes about 75 MJ of energy and emits 3 kg of CO₂ — less than 91% of polymer grades. Typical recycled content is 0%.
Manufacturability7
CPVC IM's machinability is very good (78/100, better than 81% of polymer grades); weldability very good (70/100); formability good (55/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with CPVC IM
Is CPVC easy to machine?
Machines easily with sharp, high-rake carbide tools, high speed and light feeds; use air or flood coolant to avoid heat build-up and gummy edges, and avoid deep unrelieved stress in threaded sections.
Can CPVC be welded?
Joined by solvent cement (CPVC-specific cement, not PVC) or hot-gas/hot-plate welding; never hot-melt butt-fuse like PE and never flame-heat, since >220 °C releases HCl.
Can CPVC be formed, bent or molded?
Extrudes and injection molds in a narrow window (185–210 °C melt, 40–75 °C mold) with corrosion-resistant screws/tools, generous venting and no hang-up; thermoforms at ~130–160 °C.
What surface finishes work on CPVC?
Not paintable without primer and not platable; parts are typically used as-molded, or lightly sanded/buffed—solvent wipe with ketones will craze the surface.
CPVC 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 |
|---|---|---|
| chlorine (bound, of resin)characterizing parameter of CPVC resin, not a separate additive | 63 – 69 | 67 |
| tin/Ca-Zn heat stabilizerorganotin mercaptide typical for pipe compounds | 1.5 – 4 | 2.5 |
| impact modifier (acrylic/CPE)higher in impact-modified variants | 0 – 8 | 4 |
| process aid / lubricant (acrylic, wax) | 1 – 4 | 2 |
| TiO2 pigmentUV screening for outdoor pipe | 0 – 3 | 1.5 |
| vinyl chloride (post-chlorinated PVC bacbase resin; bound chlorine content 63–69 wt% of resin vs 56.7% for PVC | ≥ 88 (balance) |
CPVC IM — frequently asked
What is CPVC IM used for?
CPVC IM is typically used for hot water plumbing pipe and fittings, fire sprinkler piping, chemical process piping and valve bodies, corrosive drain and vent lines, tank fittings and machined fluid blocks and duct and fume-handling sheet fabrications. In short: high-temp chlorinated PVC.
What is the yield strength of CPVC IM?
CPVC IM has a typical yield strength of 44 MPa (6.38 ksi) and a tensile strength of 48 MPa (6.96 ksi) — weaker than 60% of polymer grades. Strength varies by condition: see the 4 listed tempers.
Is CPVC IM easy to machine?
Yes — machinability is rated very good (78/100, better than 81% of polymer grades). Machines easily with sharp, high-rake carbide tools, high speed and light feeds; use air or flood coolant to avoid heat build-up and gummy edges, and avoid deep unrelieved stress in threaded sections.
Can CPVC IM be welded?
Yes — weldability is rated very good (70/100). Joined by solvent cement (CPVC-specific cement, not PVC) or hot-gas/hot-plate welding; never hot-melt butt-fuse like PE and never flame-heat, since >220 °C releases HCl.
What surface finishes work on CPVC IM?
Not paintable without primer and not platable; parts are typically used as-molded, or lightly sanded/buffed—solvent wipe with ketones will craze the surface.
Can CPVC IM be formed, bent or molded?
Extrudes and injection molds in a narrow window (185–210 °C melt, 40–75 °C mold) with corrosion-resistant screws/tools, generous venting and no hang-up; thermoforms at ~130–160 °C.
What is the maximum service temperature of CPVC IM?
CPVC IM is rated for continuous use to about 88°C (190 °F), and briefly to 105°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in CPVC IM?
Yes — CPVC IM is available for CNC machining, sheet metal and injection molding; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM D1784 — Rigid PVC and CPVC Compounds (cell classification) — ASTM (2020)
- ASTM F441/F441M — CPVC Plastic Pipe, Schedules 40 and 80 — ASTM (2020)
- ASTM F493 — Solvent Cements for CPVC Pipe and Fittings — ASTM (2020)
- Corzan CPVC industrial piping systems engineering & physical property data — Lubrizol (2023)
- Engineered Materials Handbook Vol. 2: Engineering Plastics — ASM International (1988)
- CAMPUS / UL Prospector rigid CPVC compound datasheets — CAMPUS / UL (2024)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.