Material class
PET-CF — carbon-fiber-reinforced PET
A carbon-fiber-reinforced PET engineering polymer. Roughly 17% short carbon fiber by weight gives it the highest stiffness and the highest heat-deflection point of anything we build with, while staying light. This is the backbone material of the Bearly Defense line.
The shape of the material
Five properties, each scaled to the strongest material in the lineup so the reach on every spoke reads as a share of best-in-class. PET-CF is filled in the accent colour; the dashed outline is ABS, a familiar commodity polymer, shown for reference only.
Lightness is density read inversely (lighter = further out); durability is notched impact strength. Each spoke is scaled to the best material for that property.
Spec sheet
Every tile carries the real figure, its ISO standard, and a four-bar comparison across the lineup and the ABS reference. The accent bar is PET-CF; ABS is the commodity reference we do not build with.
The carbon fiber is what buys the stiffness and heat resistance.
Full comparison
The same properties across every material we build with, with PET-CF highlighted. ▲ marks the strongest material in each row. The ABS column is a reference commodity polymer only.
| Property | PET-CF | ASA | PETG | ABS · ref |
|---|---|---|---|---|
| Tensile strength MPa | 65.9 | 43.8 | 31.9 | 33.3 |
| Tensile modulus MPa | 5,481 | 2,379 | 1,472 | 2,174 |
| Flexural strength MPa | n/a | 73.4 | 53.7 | 59 |
| Impact strength (notched) kJ/m² | 5.1 | 10.3 | 5.1 | 12.6 |
| Heat deflection (0.45 MPa) °C | 147.5 | 103 | n/a | 100 |
| Density g/cm³ | 1.34 | 1.13 | 1.25 | 1.12 |
Higher is better for every row except density, which just reflects mass (no ▲ marked). Values are representative engineering figures for the material class, not a warranty of any individual item.
What the numbers mean for real gear
These numbers describe a material built for stiffness and heat. Its tensile modulus of 5,481 MPa is the highest in our lineup: it resists flexing under load, so an edge or a point holds its geometry instead of bending away from the work.
A heat-deflection point of 147.5 °C means it keeps that stiffness well past anything it will meet in a pocket, a hot car, or a summer trunk. The trade is toughness — at 5.1 kJ/m² notched impact it is stiffer than it is forgiving, so it is matched to gear meant to stay rigid rather than soak up a hard shock. At 1.34 g/cm³ it stays light for how rigid it is.
The fine print
Standards: ISO 527 / 178 / 179 / 75 / 1183 (tensile / flexural / impact / heat deflection / density).
Values shown are representative engineering figures for the material class, not a warranty or a guarantee of the performance of any individual item. Actual part performance depends on geometry, use and handling.