Same problem as the TO-3, smaller package. You've got a TO-220 that needs isolating from the heatsink and you're tired of the grease-and-pray approach or watching mica flake off at the edges. These grey silicone-rubber washers handle both the electrical isolation and the thermal path in one piece. 4 kV dielectric breakdown, 94V-0 flammability. No cleanup, no re-greasing after a year. Twenty in the pack so the next board build doesn't leave you short. Slap it under the tab, tighten the screw, move on to the next component
| brand | Jaycar |
| category | Electronics & Components |
| subcategory | Electronic Components |
| transistor_package | TO-220 |
| material | Silicone impregnated rubber |
| colour | Grey |
| tensile_strength | 40 kg/cm² |
| elongation | 80% |
| dielectric_breakdown_voltage | 4000 V / 0.3 mm |
| thermal_conductance_coefficient | 2.4 × 10⁻³ |
| flammability_class | 94V-0 / 0.3 mm |
| dimensional_stability | 0.2% change / 0.3 mm |
| pack_quantity | 20 |
| sku | HP1155 |
