40pcs TO-3 Silicone Mica Insulation Pads & Washers | Transistor

TO-3 Silicone Mica Insulation Pads – 40-Piece Pack

Keep your electronics running efficiently with these high-quality TO-3 Mica Insulation Pads. Designed for use with TO-3 package transistors and other power components, these silicone mica sheets provide excellent electrical isolation while allowing effective heat dissipation to heatsinks and mounting surfaces. Whether you're building amplifiers, power supplies, or repairing vintage electronics, these insulation washers are an essential component in any electronics toolkit.

Key Features

• Material: High-grade silicone mica — combines the electrical insulating properties of mica with the flexibility and durability of silicone
• Application: Specifically sized for TO-3 transistor packages; ideal for power transistors, MOSFETs, and similar components
• Heat Resistant: Capable of withstanding high operating temperatures, ensuring long-lasting performance in demanding electronic assemblies
• Electrical Isolation: Prevents short circuits between transistor casings and heatsinks or chassis while maintaining efficient thermal transfer
• Quantity: Comes in a convenient pack of 40 pieces — plenty for multiple projects or repairs
• Brand New & High Quality: Each pad is inspected for consistent size and material integrity

Specifications

• Item Type: Insulation Pads / Washers
• Package: TO-3
• Material: Silicone Mica
• Quantity: 40 pcs per pack
• Country of Origin: Made in China

What's in the Box?

• 40 × TO-3 Silicone Mica Insulation Pads / Washers

Important Notes

• Photos may not reflect actual size — please refer to the specifications above for dimensional details.
• Due to manual measurement, minor dimensional tolerances of ±5–10 mm may occur.
• Colors may vary slightly due to monitor settings, lighting, and screen calibration.

Safety & Standards

For guidance on electrical safety in DIY and professional electronic assemblies, refer to the U.S. Consumer Product Safety Commission (CPSC), which provides resources on safe use of electrical components and assemblies.

Frequently Asked Questions

Q: What are TO-3 silicone mica insulation pads used for?

A: TO-3 silicone mica insulation pads are used to electrically isolate TO-3 package transistors (and similar power components) from heatsinks or metal chassis, while still allowing heat to transfer away from the component efficiently. This prevents short circuits and protects your circuit.

Q: Are these insulation washers compatible with all TO-3 transistors?

A: Yes — these pads are specifically designed for the standard TO-3 package footprint, making them compatible with a wide range of TO-3 power transistors, audio amplifier output transistors, and MOSFETs that use the TO-3 case style.

Q: How many insulation pads come in the pack?

A: Each pack includes 40 pieces, giving you an ample supply for multiple projects, repairs, or builds.

Q: What makes silicone mica better than plain mica for insulation pads?

A: Silicone mica combines the excellent electrical insulation and heat resistance of mica with the flexibility and conformability of silicone. This results in a pad that seats more evenly against mounting surfaces, improving both electrical isolation and thermal conductivity compared to rigid mica alone.