3M 8427-12 Cold Shrink Connector Insulators
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Manufacturer 3M
Mfg Catalog # 8427-12
NorthEast Part # 16263


  • Specially designed for primary insulation of solid dielectric insulated wires and cable splicing rated to 1000 volts
  • Simple installation which requires no tools
  • 3M™ Cold Shrink Connector Insulators 8420 and 8430 Series are designed using 3M’s proprietary cold shrink delivery system. Products are supplied prestretched on a removable core for efficiency and ease of installation. Removal of the core (unwinding) after positioning the splice allows the product to shrink into position forming a moisture-tight seal. The live memory action of the specially formulated EPDM material promotes a permanent, durable environmental seal and insulation, with a typical operating temperature range from -40–194°F (-40–90°C). The 8420 insulator meets requirements of ANSI C119-1 and Western Underground Guide 2.14 for secondary splices rated up to 1 kV. Applications: Primary electrical insulation for all solid dielectric (rubber and plastic) insulated wire and cable splicing rated to 1000 V. Good for repairs and environmental sealing for communication and other non-electrical applications. Important: Use insulation jacket or connector O.D. for final ordering criteria. * Mastic pads included for cable O.D. build-up. ** Kit contains adapters. *** These sizes are listed for availability only and are not designed to be used as primary insulation. These tubes are for conduit sealing and breakouts. ****Maximum connector length: 5.625” “Point of Purchase” packaging designated by “P”. Example: 8423-6P
  • Sealing of terminal lug barrels, conduit couplings and conduit-to-cable breakouts
  • Made of black EPDM rubber
  • Made of EPDM rubber which contains no chlorides or sulfur
  • Withstands temperatures of -40 to 194 degrees F (-40 to 90 degrees C)
  • Environmental sealing for communication and other non-electrical applications

Legal Disclaimer

  • The designation that a product is Manufactured in the USA means the product undergoes substantial transformation in one of our U.S. Manufacturing plants. Some products contain imported components.
  • Note: 3M products offered on a government contract that require country of origin representation must be certified by 3M Trade Compliance. Contact customer service at 800-245-3573 to request a certificate.


  • 3M ID: 80610134035
  • Application: Insulation, mechanical protection, repair
  • Brand: 3M™
  • Cable Shielding: Non-shielded || Tape Shield || UniShield® || Wire Shield
  • Cable Type: Non-Shieled, Solid Dielectric Power Cable
  • Case Quantity: 10
  • Color Family: Black
  • Conductor Material: Aluminum || Copper
  • Conductor Size Range: 250-400 kcmil
  • Conductor Sizes: 250 kcmil || 300 kcmil || 350 kcmil || 400 kcmil
  • Inner Diameter After Shrink (Imperial): 0.661 in
  • Inner Diameter After Shrink (Metric): 16.8 mm
  • Inner Diameter Before Shrink (Imperial): 1.382 in
  • Inner Diameter Before Shrink (Metric): 35.1 mm
  • Manufacturing Origin: USA
  • Material: EPDM Rubber
  • Maximum Connector Length: 8.0 in
  • Maximum Connector Length (Metric): 203.2 mm
  • Maximum Operating Temperature (Celsius): 90 Degree Celsius
  • Maximum Operating Temperature (Fahrenheit): 194 Degree Fahrenheit
  • Minimum Operating Temperature (Fahrenheit): -40 Degree Fahrenheit
  • Number of Conductors: 1
  • Overall Length (Imperial): 12 in
  • Overall Length (Metric): 304.8 mm
  • Product Color: Black
  • Product Type: Splice
  • Relaxed Tube Length: 12 in
  • Relaxed Tube Length (Metric): 304.8 mm
  • Splice Type: Cold Shrink
  • Voltage: 1 kV
  • Voltage Application: Low Voltage


UPC 05400734459
Product Description Quick and easy installation, no special tools and no heat requiredSeals tight, retains resiliency and pressureAccommodates a wide range of cable sizesResists acids, alkalis and ozoneNo mastic or tape required to seal
GTiN 00054007344599
Length 12 in
Size 250 kcmil; 300 kcmil; 350 kcmil; 400 kcmil
Color Black
Voltage 1 kV
Type Cold Shrink Splice
Splice Type Cold Shrink
Material Aluminum; Copper
Product Type Splice
Number of Conductors 1
Conductor Size 250 MCM
Cable Type Power Cable
Family Brand Name 3M
Max Operating Temperature 194 degrees F
Overall Length 12 in

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