McMaster-Carr logo
    Forward
    Enter e-mail addresses in the fields below
    Message
    Cancel
    Print
    How can we improve?
    Comments
    E-mail address (if you would like a response)
    77 Products

    For Use With

    For Shape

    Attachment Type

    Knockout Plugs for Enclosures

    Guard your electrical components from debris and pesky critters. Use these plugs to block unused conduit knockouts in enclosures, outlet boxes, junction boxes, and electrical panels.
    Snap In—Press these plugs into knockouts from the outside until they snap into place—there’s no need to reach inside. All have built-in clips for a secure hold. To remove, pry them out with a flathead screwdriver.
    Clamp On—These plugs create a tighter hold than snap-in plugs but require access to both the inside and outside of the enclosure to install. Position the two metal plates of the plug on either side of the enclosure wall and tighten to sandwich the wall between them.
    For
    Knockout
    Trade
    Size
    Dia.
    For Max.
    Panel Thk.
    Head
    Dia.
    Pkg.
    Qty.
    Pkg.
    Snap In
    Image of Product. Front orientation. Electrical Enclosure Plugs. Knockout Plugs for Enclosures, Snap In.
     
    Steel
    1/2
    		7/8"1/8"1 1/16"250000000000000
    3/4
    		1 1/8"1/8"1 1/4"25000000000000
    1
    		1 3/8"1/8"1 1/2"25000000000000
    1 1/4
    		1 3/4"1/8"1 13/16"25000000000000
    1 1/2
    		2"1/8"2 3/16"25000000000000
    2
    		2 1/2"1/8"2 11/16"10000000000000
     
    Clamp On
    Image of Product. Front orientation. Electrical Enclosure Plugs. Knockout Plugs for Enclosures, Clamp On.
     
    Zinc-Plated Steel
    1/2
    		7/8"1/16"1 1/8"1000000000000
    3/4
    		1 1/8"1/16"1 3/8"1000000000000
    1
    		1 3/8"1/16"1 5/8"1000000000000
    1 1/4
    		1 3/4"1/16"2 1/16"1000000000000
    1 1/2
    		2"1/16"2 7/16"1000000000000
    2
    		2 7/16"1/16"2 15/16"1000000000000
    2 1/2
    		2 15/16"1/16"3 3/4"1000000000000
    3
    		3 9/16"1/16"4 1/2"1000000000000
    3 1/23 3/4"1/16"5"1000000000000
    4
    		4 5/8"1/16"5 1/2"10000000000000
     

    Watertight Knockout Plugs for Enclosures

    Image of Product. Front orientation. Electrical Enclosure Plugs. Watertight Knockout Plugs for Enclosures.
    Don't let water sneak into unused conduit knockouts. These plugs include a gasket that locks out moisture and dust to keep your electrical components dry and contaminant-free.
    Clamp On—These plugs create a tighter hold than snap-in plugs but require access to both the inside and outside of the enclosure to install. Position the two metal plates of the plug on either side of the enclosure wall and tighten to sandwich the wall between them.
    Oil-Resistant Powder-Coated Steel—The coating creates a barrier against water, mild detergents, and oil. However, if scratched, the underlying steel may rust.
    Corrosion-Resistant 304 Stainless Steel—Won't corrode from frequent washdowns and can stand up to most cleaners, detergents, and oil.
    Chemical-Resistant Fiberglass—Won’t break down when exposed to acids, solvents, salt water, and oil. These plugs are also a lightweight alternative to stainless steel.
    For
    Knockout
    Trade
    Size
    Dia.
    For Max.
    Panel Thk.
    Head
    Dia.
    For Enclosure Rating
    Certification
    Specs.
    Met
    Each
    Clamp On
     
    Oil-Resistant Powder-Coated Steel
    1/2
    		7/8"0.31"1 3/8"NEMA 13, NEMA 4, IP66
    		CSA Certified, UL Recognized Component
    		UL 508A0000000000000
    3/4
    		1 1/16"0.31"1 9/16"NEMA 13, NEMA 4, IP66
    		CSA Certified, UL Recognized Component
    		UL 508A000000000000
    1
    		1 3/8"0.31"1 7/8"NEMA 13, NEMA 4, IP66
    		CSA Certified, UL Recognized Component
    		UL 508A000000000000
    1 1/4
    		1 11/16"0.31"2 3/16"NEMA 13, NEMA 4, IP66
    		CSA Certified, UL Recognized Component
    		UL 508A000000000000
    1 1/2
    		2"0.31"2 1/2"NEMA 13, NEMA 4, IP66
    		CSA Certified, UL Recognized Component
    		UL 508A000000000000
    2
    		2 1/2"0.31"3"NEMA 13, NEMA 4, IP66
    		CSA Certified, UL Recognized Component
    		UL 508A000000000000
    2 1/2
    		3"0.31"3 1/2"NEMA 13, NEMA 4, IP66
    		CSA Certified, UL Recognized Component
    		UL 508A000000000000
    3
    		3 5/8"0.31"4 1/8"NEMA 13, NEMA 4, IP66
    		CSA Certified, UL Recognized Component
    		UL 508A000000000000
    4
    		4 5/8"0.31"5 1/8"NEMA 13, NEMA 4, IP66
    		CSA Certified, UL Recognized Component
    		UL 508A000000000000
     
    Corrosion-Resistant 304 Stainless Steel
    1/2
    		7/8"0.31"1 3/8"NEMA 13, NEMA 4X, IP66
    		CSA Certified, UL Recognized Component
    		UL 508A000000000000
    3/4
    		1 1/16"0.31"1 9/16"NEMA 13, NEMA 4X, IP66
    		CSA Certified, UL Recognized Component
    		UL 508A000000000000
    1
    		1 3/8"0.31"1 7/8"NEMA 13, NEMA 4X, IP66
    		CSA Certified, UL Recognized Component
    		UL 508A000000000000
    1 1/4
    		1 11/16"0.31"2 3/16"NEMA 13, NEMA 4X, IP66
    		CSA Certified, UL Recognized Component
    		UL 508A000000000000
    1 1/2
    		2"0.31"2 1/2"NEMA 13, NEMA 4X, IP66
    		CSA Certified, UL Recognized Component
    		UL 508A000000000000
    2
    		2 1/2"0.31"3"NEMA 13, NEMA 4X, IP66
    		CSA Certified, UL Recognized Component
    		UL 508A000000000000
    2 1/2
    		3"0.31"3 1/2"NEMA 13, NEMA 4X, IP66
    		CSA Certified, UL Recognized Component
    		UL 508A0000000000000
    3
    		3 5/8"0.31"4 1/8"NEMA 13, NEMA 4X, IP66
    		CSA Certified, UL Recognized Component
    		UL 508A0000000000000
    4
    		4 5/8"0.31"5 1/8"NEMA 13, NEMA 4X, IP66
    		CSA Certified, UL Recognized Component
    		UL 508A0000000000000
     
    Chemical-Resistant Fiberglass
    —1/2" to 13/16"1/4"1"NEMA 12, NEMA 6P, IP66, IP68
    		C-UL Recognized Component, UL Recognized Component
    		UL 508A00000000000
    1/2
    		7/8"1/4"1 3/16"NEMA 6P, IP66, IP68
    		——00000000000
    1/2, 3/4
    		7/8" to 1 9/32"1/4"1 1/2"NEMA 12, NEMA 6P, IP66, IP68
    		C-UL Recognized Component, UL Recognized Component
    		UL 508A000000000000
    1, 1 1/4
    		1 3/8" to 1 3/4"1/4"2"NEMA 12, NEMA 6P, IP66, IP68
    		C-UL Recognized Component, UL Recognized Component
    		UL 508A000000000000
    1 1/2, 2
    		2" to 2 9/16"1/4"2 3/4"NEMA 12, NEMA 6P, IP66, IP68
    		C-UL Recognized Component, UL Recognized Component
    		UL 508A000000000000
    2 1/2
    		3"1/4"3 3/8"NEMA 12, NEMA 6P, IP66, IP68
    		C-UL Recognized Component, UL Recognized Component
    		UL 508A000000000000
    3
    		3 5/8"1/4"4"NEMA 12, NEMA 6P, IP66, IP68
    		C-UL Recognized Component, UL Recognized Component
    		UL 508A000000000000
    3 1/24 1/8"1/4"4 1/2"NEMA 12, NEMA 6P, IP66, IP68
    		C-UL Recognized Component, UL Recognized Component
    		UL 508A000000000000
    4
    		4 5/8"1/4"5"NEMA 12, NEMA 6P, IP66, IP68
    		C-UL Recognized Component, UL Recognized Component
    		UL 508A000000000000
     

    Sanitary Threaded Plugs for Enclosures

    Image of Product. Front orientation. Electrical Enclosure Plugs. Sanitary Threaded Plugs for Enclosures.
    Image of Product. Back orientation. Electrical Enclosure Plugs. Sanitary Threaded Plugs for Enclosures.
    Super smooth with round edges that prevent bacteria buildup, these plugs are FDA compliant for food processing areas. Screw them in unused threaded holes for a more secure hold than clamp-on and snap-in plugs. These plugs include a seal that locks out moisture and dust to keep your electrical components dry and contaminant-free. Twist them in place from the outside of the enclosure and then tighten with a hex key from the inside.
    Highly-Corrosion-Resistant 316L Stainless Steel—Superior to 304 stainless steel, these plugs won’t pit or weaken when exposed to harsh chemicals, including bleach and salt water.
    Thread Size
    Head Dia.,
    mm
    For Enclosure
    Rating
    Each
    Highly-Corrosion-Resistant 316L Stainless Steel
    M10 × 1.5 mm19.7IP66
    		0000000000000
     

    Watertight Push-Button Plugs for Enclosures

    Image of Product. Front orientation. Electrical Enclosure Plugs. Watertight Push-Button Plugs for Enclosures.
    Seal unused push-button switch holes so water won't sneak in. These plugs include a gasket that locks out moisture and dust to keep your electrical components dry and contaminant-free.
    Clamp On—These plugs create a tighter hold than snap-in plugs but require access to both the inside and outside of the enclosure to install. Position the two metal plates of the plug on either side of the enclosure wall and tighten to sandwich the wall between them.
    Oil-Resistant Powder-Coated Steel—The coating creates a barrier against water, mild detergents, and oil. However, if scratched, the underlying steel may rust.
    Corrosion-Resistant 304 Stainless Steel—Won't corrode from frequent washdowns and can stand up to most cleaners, detergents, and oil.
    For Push-Button
    Hole Size, mm
    For Hole
    Dia.
    For Max.
    Panel Thk.
    Head
    Dia.
    For Enclosure Rating
    Certification
    Specs.
    Met
    Each
    Clamp On
     
    Oil-Resistant Powder-Coated Steel
    227/8"0.31"1 1/4"NEMA 13, NEMA 4, IP66
    		CSA Certified, UL Recognized Component
    		UL 508A0000000000000
    301 1/4"0.31"1 3/4"NEMA 13, NEMA 4, IP66
    		CSA Certified, UL Recognized Component
    		UL 508A000000000000
     
    Corrosion-Resistant 304 Stainless Steel
    227/8"0.31"1 1/4"NEMA 13, NEMA 4X, IP66
    		CSA Certified, UL Recognized Component
    		UL 508A000000000000
    301 1/4"0.31"1 3/4"NEMA 13, NEMA 4X, IP66
    		CSA Certified, UL Recognized Component
    		UL 508A000000000000
     

    Threaded Plugs for Enclosures

    Image of Product. Front orientation. Electrical Enclosure Plugs. Threaded Plugs for Enclosures.
    Screw into unused threaded holes in enclosures, outlet boxes, junction boxes, and electrical panels for a more secure hold than clamp-on and snap-in plugs. Use these plugs to protect your electrical components in dusty or hazardous locations. Install them from the outside.
    Pipe
    Size
    Thread Size
    Head
    Dia.
    For Enclosure
    Rating
    Hazardous Location Rating
    Certification
    Specs. Met
    Each
    Aluminum
    1/2
    		—3/4"—NEC Class I Divisions 1, 2 Groups A, B, C, D; NEC Class II Divisions 1, 2 Groups E, F, G; NEC Class III Divisions 1, 2
    		CSA Certified, UL Listed
    		UL 886, UL 1203000000000000
    3/4
    		—1"—NEC Class I Divisions 1, 2 Groups A, B, C, D; NEC Class II Divisions 1, 2 Groups E, F, G; NEC Class III Divisions 1, 2
    		CSA Certified, UL Listed
    		UL 886, UL 120300000000000
    1
    		—1 1/4"—NEC Class I Divisions 1, 2 Groups A, B, C, D; NEC Class II Divisions 1, 2 Groups E, F, G; NEC Class III Divisions 1, 2
    		CSA Certified, UL Listed
    		UL 886, UL 120300000000000
    1 1/4
    		—1 1/2"—NEC Class I Divisions 1, 2 Groups A, B, C, D; NEC Class II Divisions 1, 2 Groups E, F, G; NEC Class III Divisions 1, 2
    		CSA Certified, UL Listed
    		UL 886, UL 120300000000000
    1 1/2
    		—1 3/4"—NEC Class I Divisions 1, 2 Groups A, B, C, D; NEC Class II Divisions 1, 2 Groups E, F, G; NEC Class III Divisions 1, 2
    		CSA Certified, UL Listed
    		UL 886, UL 120300000000000
    2
    		—2 1/4"—NEC Class I Divisions 1, 2 Groups A, B, C, D; NEC Class II Divisions 1, 2 Groups E, F, G; NEC Class III Divisions 1, 2
    		CSA Certified, UL Listed
    		UL 886, UL 1203000000000000
     
    Nickel-Plated Brass
    —M12 × 1.5 mm9/16"IP54
    		—CE Marked, C-UL Recognized Component, UL Recognized Component
    		—00000000000
    —M16 × 1.5 mm11/16"IP54
    		—CE Marked, C-UL Recognized Component, UL Recognized Component
    		—00000000000
    —M20 × 1.5 mm7/8"IP54
    		—CE Marked, C-UL Recognized Component, UL Recognized Component
    		—00000000000
    —M25 × 1.5 mm1 1/8"IP54
    		—CE Marked, C-UL Recognized Component, UL Recognized Component
    		—00000000000
    —PG-7
    		9/16"IP54
    		—CE Marked
    		—00000000000
    —PG-9
    		11/16"IP54
    		—CE Marked
    		—00000000000
    —PG-11
    		13/16"IP54
    		—CE Marked
    		—00000000000
    —PG-16
    		15/16"IP54
    		—CE Marked
    		—00000000000
    —PG-21
    		1 3/16"IP54
    		—CE Marked
    		—00000000000
    —PG-29
    		1 9/16"IP54
    		—CE Marked
    		—000000000000
     

    Watertight Threaded Plugs for Enclosures

    Image of Product. Front orientation. Electrical Enclosure Plugs. Watertight Threaded Plugs for Enclosures.
    Screw into unused threaded holes to block out water with a more secure hold than clamp-on and snap-in plugs. These plugs include a gasket that locks out moisture and dust to keep your electrical components dry and contaminant-free. Install them from the outside.
    Pipe
    Size
    Thread Size
    Head
    Dia.
    For Enclosure
    Rating
    Certification
    Specs.
    Met
    Each
    Nylon
    1/2
    		—1"NEMA 4X, IP68
    		C-UL Recognized Component, UL Recognized Component
    		UL 508A0000000000000
    3/4
    		—1 5/16"NEMA 4X, IP68
    		C-UL Recognized Component, UL Recognized Component
    		UL 508A00000000000
    1
    		—1 3/4"NEMA 4X, IP68
    		——00000000000
    1 1/4
    		—2 1/16"NEMA 4X, IP68
    		——00000000000
    —M12 × 1.5 mm5/8"NEMA 4X, IP68
    		C-UL Recognized Component, UL Recognized Component
    		UL 508A00000000000
    —M16 × 1.5 mm13/16"NEMA 4X, IP68
    		C-UL Recognized Component, UL Recognized Component
    		UL 508A00000000000
    —M20 × 1.5 mm1"NEMA 4X, IP68
    		C-UL Recognized Component, UL Recognized Component
    		UL 508A00000000000
    —M25 × 1.5 mm1 5/16"NEMA 4X, IP68
    		——00000000000
    —PG-7
    		5/8"NEMA 4X, IP68
    		C-UL Recognized Component, UL Recognized Component
    		UL 508A000000000000
    —PG-9
    		13/16"NEMA 4X, IP68
    		C-UL Recognized Component, UL Recognized Component
    		UL 508A00000000000
    —PG-21
    		1 5/16"NEMA 4X, IP68
    		C-UL Recognized Component, UL Recognized Component
    		UL 508A00000000000
    —PG-29
    		1 3/4"NEMA 4X, IP68
    		——00000000000
     

    Watertight Square Plugs for Enclosures

    Image of Product. Front orientation. Electrical Enclosure Plugs. Watertight Square Plugs for Enclosures.
    Seal unused square holes on the bottom of enclosures, such as floor drainage holes. These plugs have an adhesive-gasket backing that locks out water and dust to keep your electrical components dry and contaminant-free. Stick them in place from the outside.
    For
    Hole
    Head
    Lg.
    Wd.
    For Max.
    Panel Thk.
    Lg.
    Wd.
    For Enclosure Rating
    Reaches Full
    Strength, hr.
    Certification
    Specs.
    Met
    Each
    Adhesive
     
    Polycarbonate
    2"2"0.19"3"3"NEMA 12, NEMA 4X, IP56
    		72C-UL Recognized Component, UL Recognized Component
    		UL 508A000000000000
     
    back to top