Benchmark · 4 materials
PU Cast vs UHMW-PE vs EPDM vs Silicone
All polymer grades — bands show the family's 10th–90th percentile. The best value in each row is in bold; metric first, imperial in gray.
Properties
| Property | PU Cast | UHMW-PE | EPDM | Silicone |
|---|---|---|---|---|
| Yield strengthMPa | 6 MPa1 ksi | 20 MPa3 ksi | 5 MPa1 ksi | 5 MPa1 ksi |
| Tensile strengthMPa | 50 MPa7 ksi | 40 MPa6 ksi | 10 MPa1 ksi | 10 MPa1 ksi |
| Specific strengthMPa·cm³/g | 5 | 21 | 4 | 4 |
| Densityg/cm³ | 1.2 g/cm³0.043 lb/in³ | 0.94 g/cm³0.034 lb/in³ | 1.2 g/cm³0.043 lb/in³ | 1.15 g/cm³0.042 lb/in³ |
| Max service temp°C | 90 °C194 °F | 80 °C176 °F | 130 °C266 °F | 200 °C392 °F |
| Min service temp°C | -40 °C-40 °F | -100 °C-148 °F | -40 °C-40 °F | -60 °C-76 °F |
| Electrical conductivity% IACS | < 0.001 % IACSinsulator | < 0.001 % IACSinsulator | < 0.001 % IACSinsulator | < 0.001 % IACSinsulator |
| Machinability/100 | Poor20 / 100 | Fair50 / 100 | Not recommended10 / 100 | Not recommended5 / 100 |
| Weldability/100 | Fair40 / 100 | Poor20 / 100 | Not recommended1 / 100 | Not recommended1 / 100 |
| Formability/100 | Excellent92 / 100 | Fair40 / 100 | Not recommended1 / 100 | Not recommended1 / 100 |
| Relative cost | $$ Standard | $$ Standard | $$ Standard | $$$ Premium |
| Processes | CNC, Sheet, Molding | CNC, Sheet, Molding | Sheet, Molding | CNC, Sheet, Molding |
Where each grade sits
One track per property; coloured markers are the compared grades, the shaded band is the polymer family 10th–90th percentile and the tick its median.
Yield strength6 MPa
5 MPafamily median 50 MPa89 MPa
Tensile strength50 MPa
11 MPafamily median 55 MPa95 MPa
Density1.2 g/cm³
0.97 g/cm³family median 1.2 g/cm³1.59 g/cm³
Hardness (HB equiv.)—
65 HBfamily median 170 HB481 HB
Max service temp90 °C
72 °Cfamily median 100 °C257 °C
Electrical conductivity< 0.001 % IACS
< 0.001 % IACSfamily median < 0.001 % IACS< 0.001 % IACS
Machinability20 / 100
20 / 100family median 70 / 10085 / 100
Relative cost28
14family median 2899
PU CastUHMW-PEEPDMSilicone
Strength versus weight
Manufacturing and finishing
| Capability | PU Cast | UHMW-PE | EPDM | Silicone |
|---|---|---|---|---|
| CNC machining | Yes | Yes | — | Yes |
| Sheet metal | Yes | Yes | Yes | Yes |
| Injection molding | Yes | Yes | Yes | Yes |
| Default condition | Shore A 40 | FDA | Solid | Medical Grade |
| Min. machined wall | 0.5 mm | 0.5 mm | — | 0.5 mm |
| Best machined surface | Ra 0.8 µm | Ra 0.8 µm | — | Ra 0.8 µm |
| Heat treatments | — | — | — | — |
| Chemical Etching | Yes | Yes | Yes | Yes |
| Chrome Plating (Plastic) | Yes | Yes | Yes | Yes |
| Dot Peen Marking | Yes | Yes | Yes | Yes |
| EMI Shielding Coating | Yes | Yes | Yes | Yes |
| Electro-chemical Etching | Yes | Yes | Yes | Yes |
| Embossing / Debossing | Yes | Yes | Yes | Yes |
| Hot Stamping | Yes | Yes | Yes | Yes |
| In-Mold Labeling (IML) | Yes | Yes | Yes | Yes |
| Ink Stamping | Yes | Yes | Yes | Yes |
| Laser Marking | Yes | Yes | Yes | Yes |
| Mechanical Engraving | Yes | Yes | Yes | Yes |
| Pad Printing | Yes | Yes | Yes | Yes |
| Painting | Yes | Yes | Yes | Yes |
| Soft Touch Coating | Yes | Yes | Yes | Yes |
| Spray Painting | Yes | Yes | Yes | Yes |
| UV Coating | Yes | Yes | Yes | Yes |
| Vibro Engraving / Scribing | Yes | Yes | Yes | Yes |
Typical handbook values for the default condition, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.