Heyco Knock-Out Seals

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
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

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

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

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

4002

KOS 2

2.73

69,3

.750

19,1