4-40 Fasteners | McMaster-Carr

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3,536 Products

Fastening and Joining

Socket Head Screws

Socket Head Screws

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

Rounded Head Screws

Rounded Head Screws

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

Flat Head Screws

Flat Head Screws

Fit in countersunk holes for a flush finish

Hex Head Screws

Hex Head Screws

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

Shoulder Screws

Shoulder Screws

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

Tighten and loosen by hand without the need for tools

Set Screws

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

Captive Panel Screws

Captive Panel Screws

Secure panels and enclosures while still having access to them

Jack Screws

Secure computer cables and panels

Tapping Screws

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

Studs

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

Hex Nuts

Handle most general fastening needs

Locknuts

Hold fasteners in place to prevent loosening from vibration

Coupling Nuts

Connect and extend threaded rods

Easy to tighten and loosen by hand for making frequent adjustments

Socket Nuts

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

Cap Nuts

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

Flange Nuts

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

Square Nuts

Flat sides won’t spin in channels and square holes

Standoffs

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

Standoff Caps

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

Threaded Inserts

Threaded Inserts

Create new threads or repair stripped threads

Press-Fit Nuts

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

Push Nuts

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

Rivet-Mount Nuts

Rivet-Mount Nuts

Add threads in hard-to-reach areas and materials that are too thin to be tapped

Rivet Nuts

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

Weld Nuts

Weld to metal surfaces to add permanent threads

Threaded Rods

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

Thread Adapters

Thread Adapters

Join threads of a different type, size, and gender

Push Nut Installation Tools

Push Nut Installation Tools

Press nuts and retaining rings onto threaded fasteners and shafts

Rivet Nut Tools

Rivet Nut Tools

Install rivet nuts

Fabricating and Machining

Clamps

Hold workpieces securely in place

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