Heyco Plugs Knock-Out Seals
Knock-Out Seal

Material: Nylon 6/6

Certifications:

File E51579

File 8919

Flammability Rating: 94V-2

Temperature Range: -40°F to 221°F (-40°C to 105°C)

 
  • Plugs electrical knock-outs.
  • Molded in gray color to resemble galvanized steel.
  • Installs quickly with fingertip pressure (no tool required).
  • Economical.
  • Multiple trade sizes fit 1/2" to 2" knock-out holes.
  • Convex, matte finish head tapers to a thin edge.
  • Locks firmly in boxes up to 1/8" thick (3,2 mm) [except for #4002 (KOS 2) and Thick Panel Knock-Out Seals (KOST's) which lock firmly in boxes up to 1/4" thick (6,4 mm)].
  • Locking finger steps are designed at fractional increments up to the maximum panel thickness.
  • Approximate head thickness: .062" (1,6 mm). Thickness may vary.
Heyco® Knock-Out Seals
Mounting Hole Diameter Range: 1/2" to 2" Electrical Knock-outs [.875" to 2.50" nominal (22,2 mm to 63,5 mm)]
Panel Dimensions Trade Size Part
Number
Description Part Dimensions
Maximum
Thickness
Mounting Hole
Diameter
A
Head Diameter
B
Overall Height
in. mm. in. mm. Silver Gray in. mm. in. mm.
Multiple Locking Steps for Panel Thickness up to .125" (3,2 mm)
.125 3,2   .875 22,2 1/2 3997 KOS 1/2 1.02 25,8 .45 11,5
1.093 27,8 3/4 3998 KOS 3/4 1.22 31,0
1.375 34,9 1 3999 KOS 1 1.50 38,1
1.750 44,5 1-1/4 4000 KOS 1-1/4 1.91 48,4
2.000 50,8 1-1/2 4001 KOS 1-1/2 2.16 54,9
Multiple Locking Steps for Panel Thickness up to .250" (6,4 mm)
.250 6,4   .875 22,2 1/2 3991 KOST 1/2 1.02 25,8 .56 14,3
1.093 27,8 3/4 3992 KOST 3/4 1.22 31,0
1.375 34,9 1 3993 KOST 1 1.50 38,1
1.750 44,5 1-1/4 3994 KOST 1-1/4 1.91 48,4
2.000 50,8 1-1/2 3995 KOST 1-1/2 2.16 54,9 .58 14,7
2.500 63,5 2 4002 KOS 2 2.73 69,3 .750 19,1