5/16"-18 Nuts | McMaster-Carr

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Nut Type

Finish

Cadmium Yellow-Chromate Plated

Chrome Plated

Corrosion-Resistant Coated

Dry Film Lubricated

Galvanized

Hot-Dipped Galvanized

Hex Nut Profile

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Fastener Strength Grade/Class

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System of Measurement

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Unified Standard Class 1A

Unified Standard Class 1B

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Unified Standard Class 3B

Washer Material

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DFARS Specialty Metals

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Compliant with Exemptions

Not Compliant

REACH

Compliant

Not Compliant

Export Control Classification Number (ECCN)

1,353 Products

Fastening and Joining

Hex Nuts

Handle most general fastening needs

97 products

Locknuts

Hold fasteners in place to prevent loosening from vibration

61 products

Flange Nuts

The flange distributes pressure, so you don't need a washer

37 products

Cap Nuts

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

28 products

Coupling Nuts

Connect and extend threaded rods

27 products

Thumb Nuts

Easy to tighten and loosen by hand for making frequent adjustments

37 products

Square Nuts

Flat sides won’t spin in channels and square holes

11 products

Tamper-Resistant Nuts

Hard to detach without special tools to prevent unwanted removal

12 products

Socket Nuts

Install in recessed holes and tight spots where a wrench won’t fit; also known as Allen nuts

2 products

Push-Button Nuts

Disengage the threads to quickly slide along threaded rods

3 products

Split Nuts

Swivel to attach at any point on a threaded rod for quick installation

1 product

Sealing Nuts

Prevent leaks and block out contaminants with a rubber seal

1 product

Weld Nuts

Weld to metal surfaces to add permanent threads

40 products

Rivet Nuts

Add threads to thin panels with access from only one side; also known as blind inserts

45 products

Threaded Inserts

Create new threads or repair stripped threads

171 products

Clip-On Nuts

Slide onto the edge of thin panels to create a fastening point

7 products

Screw-Mount Nuts

Mount with screws, rivets, and nails to add threads to a surface

6 products

Press-Fit Nuts

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

8 products

Dowel Nuts

Form joints in blind holes in wood

4 products

Snap-In Nuts

Push into square holes in thin materials to add bolts for aligning off-center parts

8 products

Adhesive-Mount Nuts

Attach threads to material that’s too thin for a threaded insert

10 products

Tube-Connecting Nuts

Push inside tubes to join them with a threaded stud instead of welding

7 products

Push Nuts

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

2 products

Binding Barrels and Screws

Thread together for a low-profile fastener

71 products

Thread Adapters

Join threads of a different type, size, and gender

363 products

Studs

Press, weld, or screw in place to add a threaded fastening point

57 products

Thumb Screws

Tighten and loosen by hand without the need for tools

14 products

Standoffs

Threaded to separate or connect parts as well as position components in assemblies

Turn fasteners with an external drive style without slipping and damaging the drive

1 product

Building and Machinery Hardware

T-Slotted Framing Fasteners

Secure brackets and other accessories to T-slotted rails

17 products

Strut Channel Framing and Fittings

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

19 products

Handle Nuts

Attach to threaded shafts to quickly turn the shafts by hand

3 products

Leveling Mount Inserts

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

6 products

Fabricating and Machining

T-Slot Nuts

Combine with setup studs or bolts to mount fixtures to machine tables

10 products

Fixture Kits

Everything needed to mount workpieces of different sizes to your machine table

2 products

Fixture Clamps

Secure your workpiece to a fixture table so it won't move during machining

4 products

Setup Studs

Secure setup clamps and fixtures to your machine table or assemble heavy machines

29 products

Lathe Chuck Jaw Nuts

Secure jaws to a CNC lathe chuck

1 product

Material Handling

Eye Nuts

Pair with bolts or threaded rod to lift and hang components

4 products

Turnbuckles

Twist the body or end fittings to adjust the length and tension of attached rope and chain

8 products