5/16"-18 Fasteners | McMaster-Carr

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Stainless Steel

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Partially Threaded

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Specifications Met

Federal Specification

Rounded Head Style

Tensile Strength

Less than 10,000 psi

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

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Metric Class 6g

Metric Class 6H

Unified Standard Class 1A

Unified Standard Class 1B

Unified Standard Class 2A

Unified Standard Class 2B

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Unified Standard Class 3B

DFARS Specialty Metals

REACH

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Compliant with Exemptions

Export Control Classification Number (ECCN)

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4,844 Products

Fastening and Joining

Rounded Head Screws

Rounded Head Screws

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

Socket Head Screws

Socket Head Screws

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

Hex Head Screws

Hex Head Screws

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

Flat Head Screws

Flat Head Screws

Fit in countersunk holes for a flush finish

Carriage Bolts

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

Tighten and loosen by hand without the need for tools

12-Point Screws

12-Point Screws

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

Shoulder Screws

Shoulder Screws

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

Studs

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

Set Screws

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

Elevator Bolts

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

Tapping Screws

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

Hold-Down Bolts

Hold-Down Bolts

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

T-Bolts

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

Square Head Screws

Square Head Screws

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

Captive Panel Screws

Captive Panel Screws

Secure panels and enclosures while still having access to them

Wood Screws

Fasten material to wood or pieces of wood to each other

Hex Nuts

Handle most general fastening needs

Tamper-Resistant Nuts

Tamper-Resistant Nuts

Hard to detach without special tools to prevent unwanted removal

Locknuts

Hold fasteners in place to prevent loosening from vibration

Flange Nuts

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

Easy to tighten and loosen by hand for making frequent adjustments

Cap Nuts

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

Push-Button Nuts

Push-Button Nuts

Disengage the threads to quickly slide along threaded rods

Square Nuts

Flat sides won’t spin in channels and square holes

Split Nuts

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

Coupling Nuts

Connect and extend threaded rods

Socket Nuts

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

Sealing Nuts

Prevent leaks and block out contaminants with a rubber seal

Rivet Nuts

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

Clip-On Nuts

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

Threaded Inserts

Threaded Inserts

Create new threads or repair stripped threads

Adhesive-Mount Nuts

Adhesive-Mount Nuts

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

Dowel Nuts

Form joints in blind holes in wood

Weld Nuts

Weld to metal surfaces to add permanent threads

Screw-Mount Nuts

Screw-Mount Nuts

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

Press-Fit Nuts

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

Tube-Connecting Nuts

Tube-Connecting Nuts

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

Snap-In Nuts

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

Push Nuts

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

Binding Barrels and Screws

Binding Barrels and Screws

Thread together for a low-profile fastener

Anchors

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

Threaded Rods

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

Single-End Studs

Single-End Studs

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

Thread Adapters

Thread Adapters

Join threads of a different type, size, and gender

Quick-Release Pins

Quick-Release Pins

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

Dowel Pins

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

Taper Pins

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

Standoffs

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

Rivet Nut Tools

Rivet Nut Tools

Install rivet nuts

Anchor Installation Tools

Anchor Installation Tools

Drive with a hammer to expand and secure anchors in place

Magnets

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

Building and Machinery Hardware

T-Slotted Framing Fasteners

T-Slotted Framing Fasteners

Secure brackets and other accessories to T-slotted rails

Bolt-Together Framing and Fittings

Bolt-Together Framing and Fittings

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

Strut Channel Framing and Fittings

Strut Channel Framing and Fittings

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

Knobs

Position, tighten, and secure fixtures and equipment

Handle Nuts

Attach to threaded shafts to quickly turn the shafts by hand

Cam Handles

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

Leveling Mount Inserts

Leveling Mount Inserts

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

Material Handling

U-Bolt Plates

Reinforce mounted U-bolts for a more secure hold

U-Bolts

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

Routing Rings

Suspend wire and cable by feeding it through the eyehole

Eyebolts

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

Turnbuckles

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

Eye Nuts

Pair with bolts or threaded rod to lift and hang components

Hoist Rings

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

Rope Cleats

Temporarily secure rope

Fabricating and Machining

Fixturing Clamps

Fixturing Clamps

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

T-Slot Nuts

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

Fixturing Kits

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

Setup Studs

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

Lathe Chuck Jaw Nuts

Lathe Chuck Jaw Nuts

Secure jaws to a CNC lathe chuck

Electrical

Battery Terminal Fasteners

Battery Terminal Fasteners

Replace bolts in battery terminals

Battery Terminal Adapters

Battery Terminal Adapters

Convert one battery terminal style to another

Fluid Handling

Float Rods

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

Power Transmission

Connecting Rods

Connecting Rods

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

The quick brown fox jumped over the lazy dog. Pedestal (35" Ht. x 4" Wd. x 4" Dp.)