3M
3M 2229-P Scotch-Seal Mastic Tape 125 mil 2-1/2 x 3-3/4 in PK40 electrician tool
Self-fusing mastic strips seal and insulate splices up to 1000 volts and 175 °F, supplied in a 40-piece pack
- 125 mil mastic thickness seals out moisture
- Rated to 175 °F for high-temperature environments
- UV-resistant vinyl backing withstands outdoor exposure
- Meets ASTM D1000 and D150 standards
- Pack of 40 strips covers multiple jobs
Electrical insulation tape
3M Scotch-Seal 2229 mastic tape is a vinyl-backed strip with a mastic adhesive designed for sealing and insulating electrical connections up to 1,000 volts. The black strips measure 2-1/2 inches wide by 3-3/4 inches long and come in a pack of 40 for professional electrician use.
Build and daily handling
Each strip is 125 mil thick, giving a substantial self-fusing layer that conforms to irregular shapes and resists UV exposure for outdoor durability. The vinyl backing protects the mastic core during handling, while the strip format allows quick, tool-free application on splices, terminals and cable jackets.
Voltage and temperature limits
The tape is rated for a maximum of 1,000 volts and a continuous operating temperature of 175 degrees F, with compliance to ASTM D1000 and D150 test standards. These ratings define the safe envelope for high-voltage sealing and thermal stress; applications beyond these limits require a different insulation system.
Highlights
- 125 mil mastic thickness seals out moisture
- Rated to 175 °F for high-temperature environments
- UV-resistant vinyl backing withstands outdoor exposure
- Meets ASTM D1000 and D150 standards
- Pack of 40 strips covers multiple jobs
Specifications
| Brand | 3M |
|---|
Questions about this item
What does the 1000-volt rating mean for the Scotch-Seal 2229 mastic tape?
The tape is rated for a maximum of 1000 volts, so it is suitable for insulating and sealing low-voltage electrical connections up to that limit.
What are the exact dimensions of each strip in the pack?
Each strip measures 2-1/2 inches wide by 3-3/4 inches long with a thickness of 125.0 mil, supplied as individual pieces in a pack of 40.
How do you apply the mastic tape correctly, and what is the common mistake?
Remove the liner, stretch the tape slightly, and wrap it with half-lap coverage so the mastic fuses into a void-free seal; the frequent error is failing to stretch it enough, which leaves gaps.
Also in this aisle
People compared these
Same shelf, same checkout — eight coins and a 30-minute rate lock.
