The short answer
General-purpose injection polycarbonate typically runs 1.19–1.20 g/cm³ density, 60–66 MPa tensile yield strength, 650–850 J/m notched Izod on 3.2 mm bars and 124–132°C / 255–270°F heat deflection at 1.8 MPa. Melt flow is reported at 300°C / 1.2 kg, and common classes sit near MFR 10, 15–18 and 20. Higher flow fills thinner walls but gives up some impact. Clear grades transmit about 87–89% of light at 2.5–3 mm.
Have a part number or drawing callout?
Paste it as written. A polymer chemist will tell you which grade it calls for, suggest equivalents and quote it by email.
This page covers general-purpose polycarbonate injection grades by melt flow. Full typical values are on polycarbonate properties and the overview is on polycarbonate. Two common reference grades have their own pages: Lexan 141R and Makrolon 2805.
Typical spec window
| Property | Typical range | Test method |
|---|---|---|
| Melt flow (MFR) | About 10–20 g/10 min for GP injection grades | ASTM D1238 or ISO 1133, 300°C / 1.2 kg |
| Density | 1.19–1.20 g/cm³ | ASTM D792 or ISO 1183 |
| Tensile strength at yield | 60–66 MPa / 8,700–9,600 psi | ASTM D638 or ISO 527 |
| Flexural modulus | 2.3–2.4 GPa / 334,000–348,000 psi | ASTM D790 or ISO 178 |
| Notched Izod, 23°C, 3.2 mm bar | 650–850 J/m / 12–16 ft·lb/in | ASTM D256 (ISO 180 on ISO sheets) |
| Heat deflection, 1.8 MPa | 124–132°C / 255–270°F | ASTM D648 or ISO 75, unannealed |
| Light transmission, clear grades | 87–89% at 2.5–3 mm | ASTM D1003 or ISO 13468 |
| Mold shrinkage | 0.5–0.8% | ASTM D955 or ISO 294-4 |
| Flammability | HB for standard grades; some are V-2 at thin walls | UL 94 |
Typical ranges from published data sheets for grades in this window. Your grade’s own data sheet and the lot COA are what count.
What it’s used for
- Clear covers, lenses and light diffusers
- Electrical and electronic housings
- Appliance parts and transparent windows
- Safety and protective components
- Medical device housings, with the right grade documentation
- Automotive interior and lighting parts
How to tell grades apart
- Melt flow class. MFR around 10 (Makrolon 2805, Lexan 141 class) gives the best impact for general parts. MFR 15–18 (Lexan 121 is listed at 17.5) balances flow and toughness. MFR around 20 (Makrolon 2405) fills thin walls and long flow paths. Lower-flow grades suit thick parts and extrusion.
- UV-stabilized versions. Many base grades have a UV-stabilized twin at the same flow, such as Makrolon 2807 for 2805 and 2407 for 2405, and Lexan 143R near the 141 class. UV stabilizer slows yellowing. For long outdoor life, ask about coatings or dedicated weatherable grades.
- Mold release. Easy-release grades contain internal mold release for faster ejection. Makrolon 2805 and Lexan 143R are listed with release. Keep the same package once a part is approved, since release can affect bonding, painting and printing.
- Impact and thickness. PC notched Izod is high on 3.2 mm bars but can drop sharply on 6.4 mm bars and in the cold. Compare impact at the same bar thickness and temperature.
- Not GP. Flame-retardant (V-0), optical, medical, glass-filled and PC/ABS grades are separate families with their own specs.
What to put on your RFQ or PO
- Melt flow with the condition. MFR at 300°C / 572°F and 1.2 kg, nominal value and range.
- Clarity and color. Clear, a tint code, translucent or opaque color, and any haze or yellowness limit you test.
- UV and release. UV stabilized or not, and mold release or not.
- Flame rating. HB is standard. If you need V-2 at a stated thickness, or V-0, name it.
- Impact and heat. Notched Izod with bar thickness, and the heat deflection value your part depends on.
- Approvals. FDA, medical, UL or automotive specs, with the producer’s letter for the exact grade and color.
- COA values to check. Melt flow on each lot, and color or yellowness values for clear and pre-colored resin.
- Packaging. Gaylords or 25 kg (55 lb) bags. PC must be dried to about 0.02% moisture before molding, so ask for lined gaylords or sealed bags.
- Quantity and release size. Total quantity, how much per release and how often.
A polymer chemist reviews every request and checks the grade against your process before we quote. Every prime lot from our suppliers ships with a COA, and orders start at one gaylord.
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- Same MFR class and additive package from another producer. The closest swap. Check clarity, color, shrinkage and release on first articles. See Lexan 141R and Makrolon 2805.
- Clear and optical PC. For lenses and light guides. See clear polycarbonate.
- Acrylic (PMMA). Better scratch and UV resistance, much lower impact. See PC vs. acrylic.
- PC/ABS. Easier flow and lower heat. See PC vs. PC/ABS.
- Other options. See polycarbonate alternatives.
Common processing problems
- Silver streaks from wet resin: splay silver streaks
- Cracks near solvents or cleaners: environmental stress cracking
- Yellowing or dark streaks from heat: heat discoloration
- Yellowing outdoors: uv fading yellowing
- Bubbles in thick clear sections: voids bubbles
Common questions
What MFR polycarbonate do I need for injection molding?
Start from the MFR of the grade that runs your mold now, measured at 300°C / 1.2 kg. MFR around 10 suits most general parts, 15–18 balances flow and impact, and around 20 fills thin walls. Higher flow usually means lower impact.
What is the difference between Makrolon 2805 and 2807?
Both are medium-viscosity grades at about MVR 9 cm³/10 min (MFR 10) with easy release. 2807 is listed as the UV-stabilized version.
Does polycarbonate need to be dried?
Yes, always. Dry at about 120°C / 248°F for 2–4 hours to 0.02% moisture or less. Wet PC splays and loses molecular weight, which makes parts brittle.
Why did my PC part crack?
Common causes are molded-in stress, wet resin, sharp corners, and contact with solvents, some cleaners or oils. Check drying first, then stress and chemical exposure.
Tell us the grade you run now
A polymer chemist reviews every request, then matches your grade or finds a qualified equivalent and prices it.
What to send for an accurate quote
- The grade name, from any supplier, or a data sheet
- Color (natural, black or a custom match)
- Fill type and percentage, if any
- Melt flow, if you know it
- Quantity for this order and what you use in a year
- Ship-to city and state or province