Hole Covers | McMaster-Carr

Keep metal snap-in plugs of various sizes on hand to solve whatever problems arise. Made of steel, these plugs are our most durable plugs for panels. Their tapered prongs snap into holes to securely hold them in place.

Vented Snap-In Panel Plugs

Vents in the top allow air circulation and permit heat and fumes to escape. These plugs have tapered prongs that snap into the hole to securely hold them in place.

Locking Panel Plugs

The wings on these plugs expand against the sides of a hole to lock them in place.

Vented Locking Panel Plugs

Vents in the top allow air circulation and permit heat and fumes to escape. All of these plugs have wings that expand against the sides of the hole to lock them in place.

Clear Locking Panel Plugs

These plugs are see-through to provide visibility and light transmission. They have wings that expand against the sides of the hole to lock them in place.

Push-In Panel Plugs

Push these plugs into place for a finished appearance on both sides of a panel.

Sealing Panel Plugs

The wings on these plugs expand against the sides of a hole to form a liquid-tight seal. Pierce the plugs with round wire, cable, or tubing and they function as a grommet to create insulated holes.

Round Plugs

Snap-In Round Plugs

Flexible ridges or straps hold these plugs in place and allow them to fit a range of hole diameters.

Conductive Round Plugs

With a surface resistivity of less than 10⁵ ohms, these plugs not only dissipate electrical charges, but can be used as an electrical shield.

Antistatic Round Plugs

Keep equipment safe from electrical currents with these plugs that have a surface resistivity of less than 10¹² ohms.

Round Plugs

The hollow construction allows these plugs to compress for a snug fit in threaded and unthreaded holes.

Sealing Plugs

With a compressible flanged top, these plugs are designed to seal the ends of copper tubing often used in water supply lines, refrigerant lines, and HVAC compressors. All are sized to fit standard copper tube dimensions.

Pull-Tab Round Plugs

A time-saving alternative to threaded plugs, these plugs press in place and have an ergonomic pull tab for quick and easy removal. Use them to temporarily protect holes in objects from contaminants during storage, painting, and light fabrication.

High-Temperature Round Plugs for NPT Pipe

These plugs withstand temperatures up to 600° F to protect internally threaded NPT connections from contaminants during electropainting, paint baking, and powder coating applications.

Threaded Round Plugs for NPT Pipe

Protect internally threaded NPT connections from contaminants during fabrication and storage.

Threaded Round Plugs for BSPT Pipe

Safeguard internally threaded BSPT connections from contaminants during fabrication and storage.

Threaded Round Plugs for 37° Flared Tube

Designed to fit into 37° flared connections such as those found on JIC and SAE fittings, these plugs protect internally threaded connections from contaminants during fabrication and storage.

Threaded Round Plugs for Straight-Thread Pipe

Seal tube and hose fittings to keep their straight threads protected from contaminants during fabrication and storage.

Miniature Pull-Through Round Plugs

Also known as mouse tails, these tiny plugs fit through-hole IDs as small as 0.022”, 0.025", or 0.03”.

Flanged Pull-Through Round Plugs

Designed with a flange, these plugs protect countersunk holes during anodizing, electroplating, paint baking, and powder-coating applications. All withstand temperatures up to 600° F. Use the smaller end of the plug to pull the larger end into a through hole to form a tight seal.

High-Temperature Pull-Through Round Plugs

Good for electroplating, paint baking, and powder-coating applications, these plugs withstand temperatures up to 600° F. To form a tight seal, use the smaller end of the plug to pull the larger end into a through hole.

Chemical-Resistant Pull-Through Round Plugs

These plugs have excellent chemical resistance for masking parts during chemical finishing applications such as plating and anodizing. Use the smaller end of the plug to pull the larger end into a through hole to form a tight seal.

Tapered Plugs

Hollow Tapered Plugs

The hollow construction allows these plugs to compress for a snug fit in threaded and unthreaded holes of varying diameters.

Hollow Tapered Plug Assortments

Keep hollow tapered plugs of various sizes on hand to solve whatever problems arise. The hollow construction allows these plugs to compress for a snug fit in threaded and unthreaded holes of varying diameters.

Tapered Plugs

Often used as laboratory stoppers, these rubber plugs have good impact and abrasion resistance. They’re tapered to fit a range of hole diameters.

Expandable Tapered Plugs

Place a plug into an opening and tighten the wing nut—the sides expand to create a seal in holes of varying diameters.

Pull-Ring Tapered Plugs

Pull the two built-in rings to quickly remove these plugs. All are tapered to fit a range of hole diameters.

Miniature Tapered Plugs

Sized to fit small openings, these tiny plugs fit snugly but can be removed easily using the flange. Their tapered design fits a range of hole diameters.

Corks

Lightweight and moisture resistant, these plugs are laboratory-grade 100% natural cork. They’re tapered to fit a range of hole diameters.

Tamper-Evident Tapered Plugs

Often used on gas cylinders, these plugs cinch and lock tightly around valve heads to block the ports—they must be cut off making it clear if the cylinder has been tampered with. The plugs are tapered to fit a range of hole diameters.

High-Temperature Tapered Plugs

Good for electroplating, paint baking, and powder-coating applications, these plugs withstand temperatures up to 570° F. All are tapered to fit a range of hole diameters.

Hollow High-Temperature Tapered Plugs

The hollow construction allows these plugs to compress for a snug fit in threaded and unthreaded holes of varying diameters. Good for electroplating, paint baking, and powder-coating applications, they withstand temperatures up to 450° F.

Expandable High-Temperature Tapered Plugs

Place a plug into an opening and tighten the wing nut—the sides expand to create a seal in holes of varying diameters. Good for paint baking and powder-coating applications, these plugs withstand temperatures up to 450° F.

Miniature High-Temperature Tapered Plugs

Sized to fit small openings, these tiny plugs fit snugly but can be removed easily using the flange. They withstand temperatures up to 470° F, which makes them good for electroplating, paint baking, and powder-coating applications. All are tapered to fit a range of hole diameters.

Chemical-Resistant Tapered Plugs

These plugs have excellent chemical resistance for masking parts during chemical finishing applications such as plating and anodizing. Their tapered design fits a range of hole diameters.

Food Industry Tapered Plugs

Made of FDA listed materials, these plugs are suitable for food contact. They're tapered to fit a range of hole diameters.

Rectangular Plugs

Snap-In Rectangular Plugs

Flexible ridges securely hold these plugs in place and allow them to fit a range of hole sizes.

Push-In Rectangular Plugs

Push these plugs into an opening and friction holds them in place.

Square Plugs

Snap-In Square Plugs

Flexible ridges or straps hold these plugs in place.

Push-In Square Plugs

Push these plugs into an opening and friction holds them in place.

Metal Square Plugs

More durable than plastic plugs, these provide the most protection from abrasion and impact. Use them to eliminate sharp edges and create a finished look on metal fence and machine-guard posts. Drive them in place with a hammer for a secure fit.

Domed Square Plugs

Often used on metal furniture, these plugs provide a finished look on posts and tubes. Snap them into place and their flexible ridges will provide a secure grip.

Expansion Plugs for Castings

Also known as freeze plugs, these are commonly used to permanently seal the shallow holes left in a component during the casting process.

Fixture Plate Chip Plugs

Keep chips and shavings from clogging or damaging unused holes on fixture plates in milling machines.

Hydraulic Sealing Plugs

Permanently seal unthreaded holes in pneumatic and hydraulic components.

Ethernet Port Plugs

Shield unused RJ45 type ports on computers and other electronic equipment from debris and moisture.

Flange Caps

Adhesive-Back Flange Caps

Stick these caps on the raised surfaces of flanges or other flat surfaces for extra protection during transport and storage.

Stretchable Flange Caps

Stretch these caps over flared edges such as flanged tubing and valve handles.

Flange Caps

Snap these caps into flange bolt holes to safeguard pipe flanges during shipping, storing, and finishing applications. They all have a thick center pad to protect the flange opening and pipe threads from damage.

SAE Flange Caps

Protect SAE hydraulic flanges during shipping, storing, and finishing applications.

Caps

Tapered Caps

These flexible plastic caps are tapered to fit a variety of unthreaded and threaded objects.

Tapered Cap Assortments

Keep tapered caps of various sizes on hand to solve whatever problems arise. These flexible plastic caps are tapered to fit a variety of unthreaded and threaded objects.

High-Temperature Tapered Caps

Made of silicone, these caps withstand temperatures of 450° F for electroplating, paint-baking, and powder-coating applications. All of these flexible caps are tapered to fit a variety of unthreaded and threaded objects.

Metal Round Caps

More durable than plastic caps, these provide the most protection from abrasion and impact.

Heavy Duty Round Caps

Made of rigid plastic, these caps are more wear resistant than vinyl caps but not as flexible.

Round Caps

Slide these flexible vinyl caps on and they conform for a snug fit.

Domed Round Caps

The large domed head extends beyond the diameter of your pipe, rod, or tubing for added protection.

Roll-Resistant Round Caps

Commonly used on shipping tubes, these caps have a square head to prevent round objects from rolling during shipping and storage.

Tethered Round Caps

The tethered design allows frequent access to the ends of pipe, tubing, and other round objects without ever misplacing the cap.

Hanging Round Caps

Slide these caps over a tool handle or other round object and use the eye to hang it.

Sure-Grip Round Caps

A long, textured pull tab provides a sure grip for quick removal even when wearing gloves.

Food Industry Round Caps

Made of FDA listed materials, these caps are suitable for food contact.

Chemical-Resistant Round Caps

These caps have excellent chemical resistance for masking parts during chemical finishing applications such as plating and anodizing.

Conductive Round Caps

With a surface resistivity of less than 10⁵ ohms, these caps not only dissipate electrical charges, but can be used as an electrical shield.

Antistatic Round Caps

Keep equipment safe from electrical currents with these caps that have a surface resistivity of less than 10¹² ohms.

High-Temperature Round Caps

Good for electroplating, paint baking, and powder-coating applications, these caps withstand temperatures up to 440° F or 570° F.

Heavy Duty Angle Caps

Made of rigid plastic, these caps provide more wear resistance to the ends of angle iron than vinyl caps but are not as flexible.

Angle Caps

Place these flexible vinyl caps over the ends of your angle iron and they conform for a snug fit.

Heavy Duty Square Caps

Made of rigid plastic, these caps are more wear resistant than vinyl caps but not as flexible.

Corner Caps

Guard the corners of fragile materials such as glass and mirrors.

Rectangular Caps

Slide these flexible vinyl caps onto rectangular objects and they conform for a snug fit.

Square Caps

Slide these flexible vinyl caps on and they conform for a snug fit.

Stretchable Sealing Caps

Create an airtight seal around the tips of bottles and containers.

Stretchable Elastic Caps

Similar to a shower cap, these caps have an elastic band that allows them to stretch and cover a variety of shapes in a range of sizes.

Squeeze Top Caps

Squeeze the dome top to remove these caps. They're commonly used as thread protectors.

Threaded Caps

Protect externally threaded components from contaminants during fabrication and storage.

Propane Tank Tear-Tab Caps

Designed for propane tanks such as those on forklifts and grills, these caps protect tank valves during storage and transit. Push the caps onto the valves, then tear their tab to break the seal for easy removal.

Flexible Pull-Tab Caps

Slide these flexible vinyl caps on and they conform for a snug fit. Pull the tab for easy removal.

Tear-Tab Caps

Push these caps onto pipe and fittings, then tear their tab to break the seal for easy removal.

Heat-Shrink Round Caps

Permanently seal pipe, tubing, conduit, and even crimped electrical connections. Slide these flexible caps on and use a heat gun to tightly shrink them to the shape of whatever they are covering. Their outer surface shrinks while the inner wall flows into voids to create a sealed connection.

High-Visibility Pull-Tab Caps

A vibrant yellow color makes these caps stand out. They are made of flexible rubber that conforms for a snug fit. Pull the tab for easy removal.

Fastener Caps

Screw Caps

Conceal and protect the tops of socket head or button head screws.

Threaded Standoff Caps

Give open-ended standoffs a finished look and protect them from dirt and debris.

Hinged Fastener Caps

A one-piece hinged design allows frequent access to screw heads without misplacing the top. To conceal and protect the entire screw head, insert your screw through the hole in the base and flip the hinged top over.

Snap-On Fastener Caps

To conceal and protect the entire screw head, insert your screw through the hole in the base and snap on the top.

DIN Rail Caps

Guard the edges of DIN rail from damage and create a finished look.

Rebar Caps

Keep personnel safe from protruding rebar and pipe. Made of rigid plastic, these durable safety caps are bright orange or yellow for excellent visibility.

Stacking Caps and Targets

Weld these caps and targets to the ends of posts to create stackable shelving and racking systems.

USB Caps

Shield USB connectors from damage, contaminants, and moisture when they are not being used.

Capacitor Caps

Also known as capacitor boots, these caps protect capacitors and wire connections from damage to extend their service life. They also insulate wire terminal connections to help reduce accidental shocks.

Plumbing Fixtures and Drains

Drain Cleanout Hole Covers

Allow easy access to cleanout plugs hidden behind walls and floors.

Cleanout Plugs

Close off your drain cleanout pipe with these plugs.

Adjustable Floor Drain Covers

Cover unused drains to prevent accidents and help comply with OSHA requirements.

Floor Drain Grates

Use these drain grates in areas without vehicle traffic.

Adjustable Floor Drain Grates

Adjust these grates to fit a range of hole diameters.

Heavy Duty Floor Drain Grates

These grates are strong enough to handle a high volume of traffic, even from vehicles.

Plastic Floor Drains

These drains are an economical alternative to iron floor drains.

Iron Floor Drains

Roof Drain Grates

Roof Drains

Floor Drain Plugs

Often used to prevent spills from going down your drain, these plugs resist oil and most chemicals. They are nonabsorbent, washable, and reusable.

Sewer Drain Grate Guards

Placed under a grate, these guards have filter strips to catch oil, sediment, and other pollutants.

Sink Drains

Stoppers for Sink Drains

Bumpers, Grommets, and Trim

Furniture Grommets

Eliminate clutter on desktops, countertops, benchtops, and other work surfaces by organizing wire, cable, and cords.

Tight-Grip Push-In Bumpers

A ridge on the stem provides a tighter grip than other push-in bumpers. Push the stem into a hole for quick installation. These bumpers are commonly used as feet on instruments and bench-top equipment to keep them from sliding. They're also good as spacers between sheets of material. Also known as stem and grommet bumpers.

Push-In Bumpers

Push the stem into a hole for quick installation. These bumpers are commonly used as feet on instruments and bench-top equipment to keep them from sliding. They're also good as spacers between sheets of material. Also known as stem and grommet bumpers.

Compressible-Stem Push-In Bumpers

The stem on these bumpers compresses to fit into tight holes. Push the stem into a hole for quick installation. These bumpers are commonly used as feet on instruments and bench-top equipment to keep them from sliding. They're also good as spacers between sheets of material. Also known as stem and grommet bumpers.

Electrical

Corrosion-Resistant Washdown
Hole Plugs for Square Holes

Close 2" square holes in the floor of your enclosure with these adhesive plugs.

Heat-Shrink End Caps

Seal the end of crimped connections, such as motor coils, to protect them from moisture.

Ethernet Port Security Clips

Lock Ethernet cords in place to prevent unauthorized removal from ports.

Expansion Plugs

Wing Nut Expansion Plugs

Twist the wing nut on these plugs to expand the seal.

Square-Head Expansion Plugs

Turn the square head of the plug into the sealing ring to close off pipe openings.

T-Handle Expansion Plugs

Twist the easy-grip t-handle on these plugs to expand the seal.

Hex-Nut Expansion Plugs

Tighten the nut on these plugs to expand the seal.

Quick-Snap Expansion Plugs

Turn the cam handle to expand the seal, then snap the handle down to hold it in place.

Expansion Plugs with Bypass

Use the bypass tube on these plugs to add air, water, and other fluid to your pipeline or to relieve pressure while testing.

Air- and Water-Inflatable Plugs for Y-Joints

These extra-long plugs allow you to seal off two pipes at the same time. They have two separate inflation chambers to release back pressure gradually and prevent splash back as water clears the drain line.

Air- and Water-Inflatable Plugs

Penetrate tight pipe junctures with the most flexible expansion plugs we offer.

Air-Inflatable Plugs

Also known as pneumatic plugs, these plugs conform to wide and out-of-round pipes.

Air-Inflatable Plugs with Bypass

Use the bypass tube on these plugs to add air, water, and other fluid to your pipeline or to relieve back pressure while testing.

Deep-Reach Wing Nut Expansion Plugs

Insert these plugs deep within your pipe to seal it off from the inside.

Expansion Plugs for Tubing

These plugs are designed for metal and rigid plastic tubing.

Deep-Reach Hex Nut Expansion Plugs with Bypass

Use the bypass tube to add air, water, and fluid or relieve back pressure.

Ductwork and Louvers

Sloped Roof Vent Caps

Flat Roof Vent Caps

Wall Vent Caps

Exhaust Pipe Caps

Keep rain and debris out of vertical exhaust pipe with these caps that open with slight pressure from exhaust.

Chimney Vent Caps

Cover chimneys to reduce downdrafts and prevent obstructions from entering.

High-Temperature Chimney Vents and Fittings

Built to withstand temperatures up to 1000° F, these vent pipes and fittings are for use with boilers, furnaces, stoves, and other equipment that is fired by coal, gas, oil, propane, or wood.

Spark-Protection Chimney Vent Caps

The expanded mesh on these vent caps provides spark protection.

Gas Chimney Vents and Fittings

For use with gas-fired equipment, such as boilers and furnaces, these vent pipes and fittings withstand temperatures up to 400° F. Also known as type B gas vents.

Sorbents and Spill Control

Magnetic Spill-Control Drain Covers

Stop oil, chemicals, and other spills from going down the drain with these magnetic covers.

Spill-Control Drain Covers

Block grates and manholes to stop liquids from going in, or seal inactive drains to keep odors from leaking out.

Curb-Style Storm Drain Filters

Prevent rainwater from carrying trash, debris, and sediment into sewers.