Caps | McMaster-Carr

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Acrylic/Cotton Fabric

Adhesive

Aluminum

Aluminum Oxide

Aramid/Carbon Fiber Fabric

Aramid/Lyocell Fabric

Aramid/Modacrylic Fabric

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Aramid/Viscose Fabric

Brass

Bronze

Carbon Fiber

Carbon Fiber/Kevlar Fabric

Carbon Fiber/Polyester Fabric

Fitting Type

System of Measurement

Pipe Size

Shape

Adjustable-Angle Elbow

Thread Type

Chicago Fire Department

For Use With

Alcohol-Based Solvents

Deutsch Style Connectors

Color

Brown/Dark Brown/White

Fitting Connection

Thread Size

Gender

Tube OD

Attachment Type

Adjustable Heel Strap with Buckles

Adjustable Heel Strap with Snap Hook

Band-and-Buckle Clamp

Clamp On

Cord

Crimp-On Hose Ferrule

Elastic Heel Strap

Headband

Hook and Loop Heel Strap

Pipe Material

Pipe Schedule

Profile Shape

Inside Height

Length

RoHS

Compliant with Exemptions

Tube Material

REACH

U.S.–Mexico–Canada Agreement (USMCA) Qualifying

Yes

Export Control Classification Number (ECCN)

DFARS Specialty Metals

17,505 Products

Fluid Handling

Pipe and Fittings

Generally thicker and more rigid than tubing for distributing liquids and gases

3,170 products

Tube End Caps

Cover the ends of tube to keep out dirt and debris

394 products

Tube End Plugs

Insert into the ends of tube to keep out dirt and debris

260 products

Tube Fittings

Make threaded, push to connect, barbed, and other types of connections between lengths of tube

466 products

Tubing Flow Stops

Temporarily block water flow to make soldering repairs without waiting for your line to drain

9 products

Hose End Caps

Cover the ends of hose to keep out dirt and debris

155 products

Hose Fittings

Create threaded, barbed, quick-disconnect, and other types of connections between lengths of hose

1,367 products

Hose End Plugs

Insert into the ends of hose to keep out dirt and debris

41 products

Hose

Flexible and stronger than tubing; often used to convey liquids and gases under pressure

65 products

Expansion Plugs

Seal pipe and tubing lines when checking for leaks

346 products

Bore Sealing Plugs

Permanently seal unthreaded holes in pneumatic and hydraulic components

95 products

Air Vent Valves

Eliminate air pockets from fluid lines to maintain consistent flow and prevent surges

39 products

Breather Vents

Maintain even pressure and vacuum as temperatures change by allowing airflow in tanks and enclosures

155 products

Pressure-Relief Valves

Protect equipment by opening at a set pressure and closing when the pressure drops; for repeated use

17 products

Sights

Observe and monitor the contents of pipes, tanks, and other containers

246 products

Thermocouple Connector Covers

Shield thermocouple connectors from dust and debris

1 product

Heat Exchanger Plugs

Plug leaky internal tubes in heat exchangers

17 products

Building and Machinery Hardware

Protective Caps

Protect just about anything, including pipe, flanges, screws, and posts

1,070 products

Protective Plugs

Insert into holes in pipe, containers, panels, and parts to keep out debris

1,009 products

T-Slotted Framing and Fittings

The most versatile system, attach fittings along the continuous slots to build virtually anything

127 products

Strut Channel Framing and Fittings

Secure fittings in the U-shaped channel to route conduit and pipe or build other structures

112 products

Slip-On Framing and Fittings

Insert rails into fittings and tighten screws to make guards, railings, and racks

27 products

Locking-Slotted Framing and Fittings

Make platforms, bases, and other structures that stand up to more movement than T-slotted framing

1 product

Clamp-On Framing and Fittings

Two-piece fittings let you modify assembly stations, conveyors, and racks without dismantling them

1 product

Press-Fit Framing and Fittings

Set up temporary partitions, guards, and displays using only a hammer

2 products

Bolt-Together Framing and Fittings

Fasten through equally spaced holes to build and adjust guards, tables, and racks

1 product

Knobs

Position, tighten, and secure fixtures and equipment

503 products

Protective Feet

Add to furniture and light equipment to protect floors from scratches and wear

279 products

Leveling Mount Inserts

Slip onto equipment and furniture to add threaded-stud leveling feet

113 products

Leveling Mounts

Level machines and workbenches on uneven surfaces, reduce vibration, and protect floors

10 products

Keyhead Covers

Color-code your keys for easy identification

2 products

Hand Grips

Cover handles so they're more comfortable and secure to hold

183 products

Lockouts

Ensure that machines stay turned off to prevent accidents during maintenance work

4 products

Door Drip Guards

Divert rain and snow away from door openings

13 products

Electrical Power, Networking, and Controlling

Electrical Connector Caps

Protect data connectors when not in use

78 products

Power Connectors

Plugs, sockets, receptacles, and other connectors for powering equipment

842 products

Latching Connectors

Protect connections in wet or harsh environments while keeping them accessible

173 products

Coaxial Connectors

Plugs, sockets, receptacles, and adapters to make coaxial connections

59 products

Solenoid Valve Sockets

Pair with plugs or receptacles to connect solenoid components

11 products

Metric Circular Connectors

Plugs, sockets, receptacles, and adapters for equipment with metric connections

130 products

USB Connectors

Plugs, sockets, receptacles, and adapters to make USB connections

20 products

RJ45 Plugs

Pair with sockets or receptacles to make Ethernet connections

25 products

Audio Connectors

Plugs, sockets, receptacles, and adapters to make audio connections

26 products

D-Sub Connectors

Plugs, sockets, receptacles, and adapters for connecting computers, monitors, and printers

138 products

CB Radio Sockets

Pair with receptacles to connect CB radios

1 product

Molex Connectors

Plugs, sockets, and housings for making Molex connections

180 products

Amphenol Connectors

Attach wires to a circuit board

32 products

HDMI Adapters

Convert one HDMI size or style to another

14 products

Sure Seal Connectors

A PVC housing keeps out liquids and dust and resists chemicals

6 products

Ballast Connectors

Avoid exposure to live wires when replacing fluorescent ballasts

2 products

Mil. Spec. Connectors

Meet strict military standards or are compatible with Mil. Spec. connectors

94 products

Breakaway Connectors

If pulled or stressed, these disconnect without damaging cables and equipment

3 products

RJ45 Connector Repair Clips

Snap onto broken Ethernet plugs to restore their ability to make secure connections

1 product

Ecomate Connectors

Connect machine tools, robots, and other vibrating equipment

14 products

ix Industrial Sockets

Pair with plugs to add ix Industrial connections to printed circuit boards

6 products

AMP Connectors

Build-your-own and ready-to-use AMP connectors

80 products

DMX Connectors

Replace damaged plugs and sockets on lighting cables

2 products

Mini Connectors

Plugs, sockets, and receptacles send power and control signals to equipment and automated systems

24 products

Micro 360 Connectors

Plugs and sockets to make control and data connections in tight spaces

24 products

Han Connectors

Plugs and sockets to make Han connections

8 products

RJ45 Connector Security Clips

Lock Ethernet cords in place to prevent unauthorized removal from ports

3 products

Wire Splices, Connectors, and Taps

Join wire and protect the connection

378 products

Data Port Plugs

Keep dust, debris, and moisture out of unused computer ports

3 products

Wire Splice Covers

Seal out dust and moisture to protect electrical connectors

3 products

USB Cords

Transfer data between computers, printers, and mobile devices

252 products

Metric Circular Cords

Send power and signal to equipment with metric connections

474 products

Power Cords

Connect equipment and devices to a power source

9 products

Terminal Covers

Block out dirt and corrosion to protect battery terminals

20 products

Terminal and Splice Kits

Maintain a supply of extra terminals and splices to join and terminate wire

17 products

USB Chargers

Power up mobile devices and other electronics

21 products

Data Port Locks

Block USB or Ethernet ports from unauthorized use

9 products

Wire Splice Bits

Install twist-on wire splices using a power screwdriver or drill

2 products

Wire Splice Screwdrivers

Install twist-on wire splices

2 products

Welding Cable Connectors

Plugs and sockets to deliver power to welding cable

13 products

Electrical Enclosure Plugs

Block or seal holes in outlet boxes and enclosures to keep out debris, dust, and moisture

77 products

Electrical Enclosure Drains

Release moisture to keep components dry

4 products

Heat-Shrink Tubing End Caps

Seal moisture out of crimped electrical connections

22 products

Cold-Shrink Tubing End Caps

Seal crimped electrical connections without heat or tools to protect against moisture

4 products

Electrical Enclosure Vents

Attach to sealed enclosures so air can flow to equalize temperature and pressure

10 products

Weatherheads

Bring power into buildings and protect the entry point from rain and snow

10 products

Electrical Enclosure Drain Vents

Prevent moisture from getting trapped inside enclosures while letting air flow through

6 products

Outlet Box Covers

Enclose wiring for outlets and switches or block off unused components

86 products

Outlet Boxes

House electrical components such as on-off switches, receptacles, and dimmer knobs

7 products

DIN Rail Caps

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

2 products

Battery Vent Caps

Flip open to check water levels and fill wet-cell batteries

1 product

Capacitor Boots

Shield capacitors and wire connections to extend their service life and reduce accidental shocks

3 products

Electrical-Insulating Wire Caps

Cover live wire ends to protect against shock from accidental contact

3 products

Circuit Breaker Box Filler Plates

Conceal live electrical components in circuit breaker boxes to prevent injury and damage

2 products

Fuse Block Safety Covers

Prevent accidental shocks when handling fuse blocks and fuses

4 products

Circuit Board Connectors

Connect flat flexible cable to circuit boards

10 products

Fastening and Joining

Cap Nuts

Cover and protect threads while adding a finished look; also known as acorn nuts

423 products

Standoff Caps

Create a finished look on standoffs and protect them from dirt and debris

66 products

Quick-Release Pin Receptacles

Secure quick-release pins when you don’t have a through hole

36 products

Quick-Release Pin Retaining Caps

Hold quick-release pins in holes that are oversized or out of round

23 products

Threaded Inserts

Create new threads or repair stripped threads

1 product

Press-Fit Nuts

Push into drilled or punched holes to add threads to thin panels

2 products

Push Nuts

Press onto threads for a light duty hold that’s faster to install than typical nuts

7 products

Retaining Rings

Hold components on a shaft

273 products

Binding Barrel Caps

Pair with a plastic binding barrel post to create a custom fastener

2 products

Cartridge Sealing Caps

Slip over the tips of adhesive and sealant cartridges to keep contents from hardening

1 product

Socket Retaining Rings

Secure sockets and adapters to impact tools

39 products

Containers, Storage, and Furniture

Drum Plug Caps

Access inside drums to fill them

4 products

Drum Plugs

Seal drum lid openings

27 products

Drum Locks

Secure drum lids and openings to prevent tampering

3 products

Drum Lids

Replace the lid on your drum

16 products

Drum Covers

Protect drum lids from damage and rust

10 products

Drum Locking Rings

Clamp lids onto drums for a tight seal

7 products

Fuel Caps

Seal fuel tanks on trailers, compressors, and other equipment

2 products

Gas Tank Safety Caps

Protect valves on high-pressure gas tanks without having to remove the regulator

1 product

Gas Tank Safety Collars

Protect valves on acetylene tanks without having to remove the regulator

1 product

Dust Covers

Stretch over drums, pails, and other objects to keep out dust and debris

16 products

Helmet Bags

Carry your helmet and shield it from scratches, dents, and rain

1 product

Hard Hat Bags

Protect your hard hat from sunlight and other damaging elements to extend its life

1 product

Pail Lids

Replace the lid on your pail with one that quickly screws open and closed

2 products

Vial Caps

Take samples from vials without removing the cap

15 products

Syringe Caps

Cover syringe tips when not in use to protect them and prevent leaks

13 products

Stacking Caps and Targets

Turn the ends of posts into stackable shelving and rack systems

6 products

Hard Hat Racks

Keep hard hats close at hand, but out of the way

6 products

Pegboard Hook End Caps

Slide onto the end of pegboard hooks to protect items from scratches

2 products

Knife Sheaths

Safely store knives while protecting them from damage

7 products

Heating, Ventilation, and Air Conditioning

Duct and Fittings

Circulate air through HVAC systems using round, rectangular, and fabric duct

145 products

Air Diverters

Guide air toward your workspace or deflect unwanted drafts

9 products

Chimney Pipe and Fittings

Exhaust hot air and fumes from boilers, furnaces, and stoves

20 products

Air Conditioner Service Valve Caps

Seal off AC service valves to prevent refrigerant from leaking out

2 products

Air Conditioner Service Valves

Tap into refrigerant lines to drain and fill your system

18 products

Temperature-Controlled Outlet Adapters

Automatically turn heating and cooling devices on and off as temperatures rise and fall

3 products

Safety Equipment

Hair Covers

Catch stray hairs before they contaminate food

12 products

Hats

Shield your head from sun, rain, cold, and sparks

28 products

Hard Hat Liners

Layer under your hard hat for extra warmth

17 products

Hard Hats

Protect your head from falling objects

50 products

Hard Hat Windsocks

Stretch over your hard hat to block wind and cold

5 products

Hard Hat Cooling Pads

Soak in water to keep your head cool

5 products

Clothing Kits

Head-to-toe protection from electrical arc flashes, chemical splashes, welding sparks, and more

11 products

Hoods

Shield your head and neck from dirt, heat, cold, and electrical and welding sparks

41 products

Earplugs

Protect your hearing in loud environments without the bulk of earmuffs

98 products

Earmuffs

Dampen loud noises to protect hearing

31 products

Bandanas

Keep sun, dust, and sweat off your face

3 products

Toe and Foot Guards

Slip over shoes or boots to shield feet and toes from impact

20 products

Bump Caps

Guard against minor head bumps and scrapes

50 products

Bicycle Helmets

A multi-directional impact protection system (MIPS) reduces injury risk

1 product

Bump Cap Inserts

Tuck inside a baseball cap to protect your head from bumps and scrapes

4 products

Ear Warmers

Wrap behind your head to shield your ears from the cold and wind

1 product

Face Shields

Protect your face from dirt, chemical splashes, and electrical and welding sparks

4 products

Sweatbands

Absorb sweat from your head or arms

8 products

Earmuff and Headset Covers

Keep shared earmuffs, headsets, and headphones germ-free without sterilizing them

2 products

Neck Gaiters

Protect your neck and face from cold, heat, flames, and electrical hazards

6 products

Fire Hydrant Caps

Pair with a hook-style spanner wrench to quickly cover and uncover fire hydrants

6 products

Fire Hydrant Plugs

Pair with a hook-style spanner wrench to quickly seal fire hydrants and washdown equipment

3 products

Bearing Guards

Shield bearings from dirt, and protect fingers and tools from moving parts

20 products

Spill-Control Drain Covers

Block grates and manholes so liquid can't get in and odors can't get out

7 products

Floor Drain Plugs

Prevent oil and other spills from going down your floor drain

3 products

Fabricating and Machining

Clamp Holding Screw Tips

Cover metal holding screws to protect workpieces from scratches

12 products

Clamp Holding Screws

Replace worn holding screws in clamps or customize with different sizes or styles

52 products

Tweezer Tip Caps

Protect tweezer tips from damage

1 product

Jaw Covers for Pliers

Cover the jaws of slip-joint pliers to protect the finish of your workpiece

2 products

Vise Jaw Liners

Place over vise jaws to protect workpieces from marring

50 products

Rotary Tool Nose Caps

Attach to the end of Dremel grinders for quick accessory changes without extra tools

1 product

Fixture Plate Plugs

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

8 products

Tooling Ball Covers

Protect tooling balls when not in use

3 products

Sanding Bits

Smooth out small, recessed, and hard-to-reach areas, and also remove paint and rust

210 products

Lubricating

Grease Fitting Caps

Protect grease fittings from dirt, debris, and moisture

14 products

Grease Fitting Adapters

Mate grease fittings when the sizes and thread types don't match

41 products

Grease Fittings

Create an inlet on equipment and machinery for injecting lubricant; also known as Zerk fittings

360 products

Grease Fitting Junction Blocks

Send different types and amounts of grease from multiple grease fittings to lubricate several points

9 products

Grease Fitting Manifolds

Lubricate multiple points with the same amount and type of grease using one grease fitting

3 products

Grease Fitting Repair Tools

Remove and repair broken or clogged grease fittings and re-tap threaded holes

2 products

Grease Fitting Installation Tools

Tap to insert grease fittings in unthreaded holes

2 products

Grease Fitting Cleaning Tools

Flush out old grease, dirt, and debris from clogged fittings

2 products

Coolant Hose and Fittings

Build a custom system to deliver coolant, cutting oil, water, or air in any direction

6 products

Facility and Grounds Maintenance

Flush Valve Replacement Parts

Replace virtually any part in the most common flush valve brands

5 products

Drain Cleanouts

Create an access point to inspect and clean floor drain pipelines

3 products

Sink Drain Stoppers

Plug drains to fill up sinks and tubs

5 products

Sink Drains

Empty liquids from sinks into sewer lines

47 products

Sink Drain Strainers

Catch debris to prevent clogs and plug drains to fill sinks

6 products

Faucet Hole Covers

Close off unused faucet holes intended for soap dispensers and side sprayers

2 products

Protective Coatings

Shield surfaces from the surrounding environment

1 product

Chain Link Fencing

Everything you need to build or repair a chain link fence, from posts to gates

5 products

Fence Posts

Secure and hold up fencing

10 products

Rebar Caps

Brightly colored to alert workers to exposed rebar and pipe

4 products

Shampoo Caps

Remove contaminants from your hair with no rinsing required

2 products

Communication

Labels

Stick onto items to identify or convey information about them

17 products

Tamper-Evident Seals

Secure hasps, latches, and other connections to visibly indicate tampering

2 products

Marking Cones

Designate areas for material identification, inventory control, and pallet staging

6 products

Headsets

Make calls from computers and other devices or communicate over two-way radios

3 products

Power Transmission

Die Spring Screw Caps

Brace springs and control tension in die sets while simplifying maintenance

10 products

Material Handling

Valve Stem Caps

Keep dust and debris out of tire valves

2 products

Conveyor Guide Mounting Rod Caps

Cover the ends of conveyor guide mounting rods for a finished look

7 products

Ladder Pads

Cushion the top of ladders to protect surfaces

1 product

Pallet Load Covers

Fit over boxes on pallets to shield the tops and edges from strapping gouges and impact

3 products

Measuring and Inspecting

Variance Indicator Caps

Cover and color-code the spindle on your variance indicator

1 product

Caliper Battery Covers

Protect the battery inside your caliper

8 products

Voltage Detectors

Check for voltage in receptacles, cables, and electrical components

3 products

Sealing

Drum Plug Gaskets

Form a tighter seal in drum openings than with a drum plug alone

7 products

Drum Gaskets

Seal lids onto steel and stainless steel drums

6 products