5/16"-18 Fasteners | McMaster-Carr

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System of Measurement

Thread Size

Length

Material

Fastener Head Type

Drive Style

Tamper-Resistant Torx

Finish

Cadmium Yellow-Chromate Plated

Chrome Plated

Corrosion-Resistant Coated

Galvanized

Hot-Dipped Galvanized

Threading

Threaded on Both Ends

Head Diameter

Thread Type

Socket Head Profile

Thread Direction

Right Hand and Left Hand

Thread Spacing

Head Height

Fastener Strength Grade/Class

Drive Size

Specifications Met

Federal Specification

Tensile Strength

10,000 psi to 19,999 psi

20,000 psi to 29,999 psi

30,000 psi to 99,999 psi

100,000 psi or greater

Head Width

DFARS Specialty Metals

Compliant

Exempt

Not Compliant

Thread Fit

ASME Interference Class 5

Metric Class 6g

Metric Class 6H

Unified Standard Class 1A

Unified Standard Class 1B

Unified Standard Class 2A

Unified Standard Class 2B

Unified Standard Class 3A

Unified Standard Class 3B

REACH

Compliant

Not Compliant

RoHS

Compliant

Compliant with Exemptions

Not Compliant

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

Yes

Export Control Classification Number (ECCN)

Thread Length

5,598 Products

Fastening and Joining

Rounded Head Screws

Sit just above the surface for a low-profile finish and hold tighter than flat head screws

337 products

Socket Head Screws

With a deeper drive than flat and rounded head screws, these withstand more torque for a tighter hold

352 products

Hex Head Screws

Used with nuts to create a stronger joint than flat and rounded screws

714 products

Flat Head Screws

Fit in countersunk holes for a flush finish that won't snag on surrounding parts

257 products

Tapping Screws

Fasten a range of materials together without needing to tap the hole first

57 products

Thumb Screws

Tighten and loosen by hand without the need for tools

156 products

Shoulder Screws

Rotate parts around the cylinder under the head to guide and align them during installation

459 products

Carriage Bolts

A smooth head provides a finished look while a square neck keeps the bolt in place when using a nut

135 products

Set Screws

Exert pressure at the tip to hold parts in place, unlike screws that hold material together with threads

266 products

Studs

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

82 products

12-Point Screws

12 contact points handle more torque than a hex head while a flange eliminates the need for a washer

24 products

Elevator Bolts

Create a flush joint to allow movement in tight spaces such as grain elevators and belting systems

49 products

Square Head Screws

Turn the large flat sides with a wrench into square holes that stop further rotation

20 products

T-Bolts

Turn by hand for easy fastening, use as a handle, or attach as a point for straps and clamps

1 product

Hold-Down Bolts

Hold material under the bent head while the other end is tightened down with a nut

4 products

Wood Screws

Fasten material to wood or pieces of wood to each other

5 products

Captive Panel Screws

Secure panels and enclosures while still having access to them

7 products

Oval Head Screws

The domed top sits slightly above the surface of countersunk holes for a decorative look

9 products

Hex Nuts

Handle most general fastening needs

98 products

Tamper-Resistant Nuts

Hard to detach without special tools to prevent unwanted removal

12 products

Thumb Nuts

Easy to tighten and loosen by hand for making frequent adjustments

37 products

Locknuts

Hold fasteners in place to prevent loosening from vibration

60 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

Square Nuts

Flat sides won’t spin in channels and square holes

11 products

Push-Button Nuts

Disengage the threads to quickly slide along threaded rods

3 products

Socket Nuts

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

2 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

Clip-On Nuts

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

7 products

Rivet Nuts

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

45 products

Weld Nuts

Weld to metal surfaces to add permanent threads

40 products

Threaded Inserts

Create new threads or repair stripped threads

244 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

Create custom low-profile fasteners with binding barrel posts, caps, and screws

75 products

Anchors

Secure anything from signs to heavy machinery in concrete, brick, and drywall

43 products

Standoff Caps

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

52 products

Standoffs

Separate, position, or connect components in assemblies

2 products

Threaded Rods

Anchor, connect, or hang components in a wide variety of applications

267 products

Quick-Release Pins

Fasten or remove components on equipment with a spring-loaded retaining ball

2 products

Dowel Pins

Align parts before assembly or use as a pivot, shaft, or hinge to join moving components

39 products

Taper Pins

Fit snugly into tapered holes to secure, position, and align components

4 products

Single-End Studs

Use the unthreaded end as a pivot point, hinge, shaft, or locator pin

11 products

Thread Adapters

Join threads of a different type, size, and gender

363 products

Rivet Tools

Install and remove blind, solid, hollow, and other types of rivets

Threaded Insert Installation Tools

Install helical, key-locking, slotted-drive, and other threaded inserts

61 products

Anchor Installation Tools

Drive with a hammer to expand and secure anchors in place

1 product

Magnets

Attract or repel metal objects to hang, secure, or position them

7 products

Building and Machinery Hardware

T-Slotted Framing Fasteners

Secure brackets and other accessories to T-slotted rails

33 products

T-Slotted Framing Structural Brackets

Join T-slotted rail surfaces and corners to build virtually any structure

87 products

T-Slotted Framing Braces

Reinforce joined corners of T-slotted rails for a sturdier connection than structural brackets

15 products

Bolt-Together Framing and Fittings

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

4 products

Strut Channel Nuts

Fasten on threaded rod to connect components to strut channel

17 products

Cam Handles

For fast clamping, push down on the handle to draw two parts together

11 products

Knobs

Position, tighten, and secure fixtures and equipment

114 products

Handle Nuts

Attach to threaded shafts to quickly turn the shafts by hand

3 products

Protective Plugs

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

1 product

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

14 products

Setup Studs

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

36 products

Fixture Clamps

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

18 products

Fixture Kits

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

2 products

Toggle Clamps

Lock workpieces onto worktables or objects

44 products

Clamping Screw Mounting Bases

Thread clamping screw clamps into the holes to hold workpieces

1 product

Clamping Screw Clamps

Mount in a base or through a threaded hole, then tighten the tip to hold a workpiece in place

1 product

Lathe Chuck Jaw Nuts

Secure jaws to a CNC lathe chuck

1 product

Material Handling

Turnbuckles

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

66 products

Eyebolts

Route rope through the loop or attach hooks and shackles for lifting

79 products

Hoist Rings

Pivot to resist stress that would bend or break an eyebolt when lifting at an angle

17 products

Eye Nuts

Pair with bolts or threaded rod to lift and hang components

4 products

U-Bolt Plates

Reinforce mounted U-bolts for a more secure hold

35 products

U-Bolts

Anchor heavy pipe, tube, and conduit; stronger than routing clamps and hangers

159 products

Routing Clamps

Secure routed lines of pipe, tubing, and conduit

102 products

Routing Rings

Suspend wire and cable by feeding it through the eyehole

2 products

Rope Cleats

Temporarily secure rope

1 product

Power Transmission

Rod Ends

Use with connecting rods to support loads and control steering, tensioning, or pivoting motion

41 products

Connecting Rods

Use with rod ends and swivel joints to link components in push/pull assemblies

18 products

Electrical Power, Networking, and Controlling

Battery Terminal Adapters

Convert one battery terminal style to another

2 products

Battery Terminal Fasteners

Replace bolts in battery terminals

2 products

Battery Terminals

Connect cable to battery posts to power vehicles and machines

1 product

Fluid Handling

Float Rods

Connect valve bodies and floats to build or repair a float valve

4 products