Threaded Fasteners Stripped

Hardware Fastener FAQ

1. What’s the difference between a screw and a bolt?

A screw is typically driven into a material to form its own threads or engage a pre-tapped hole. A bolt is inserted through a hole and secured with a nut. Screws are often used for direct fastening; bolts are used for clamping assemblies.

2. When should I use a washer?

Washers distribute load, prevent surface damage, and reduce loosening. Use flat washers under bolt heads or nuts, lock washers in vibration zones, and fender washers for soft or oversized holes.

3. What does “thread pitch” mean?

Thread pitch is the distance between threads. Coarse threads are better for soft materials and quick assembly. Fine threads offer better tension control and are used in precision or high-vibration applications.

4. What’s the most common finish for fasteners?

Fastener finishes affect corrosion resistance, conductivity, appearance, and compatibility with surrounding materials. Selection depends on environment, substrate, and regulatory requirements. Common finishes include:

• Zinc-plated – General indoor use; mild corrosion resistance; bright or clear appearance
• Hot-dip galvanized – Heavy-duty outdoor use; thick zinc layer for structural steel and wood-to-concrete connections
• Black oxide – Machinery and aesthetic applications; minimal corrosion resistance; often used indoors
• Stainless steel – High corrosion resistance; ideal for sanitary, marine, and outdoor environments
• Phosphate-coated – Used on drywall and self-tapping screws; improves paint adhesion and lubricity
• Cadmium-plated – Aerospace and marine use; excellent corrosion resistance and conductivity; restricted by RoHS
• Nickel-plated – Decorative and electrical applications; smooth finish with moderate corrosion resistance
• Chrome-plated – Decorative hardware; high polish and abrasion resistance; used in furniture and automotive trim
• Mechanical galvanizing – Uniform zinc coating for threaded parts; avoids hydrogen embrittlement common in hot-dip processes

5. How do I choose the right fastener?

Choosing the right fastener means matching its mechanical function, material compatibility, and installation method to the demands of the application. Key selection factors include:

• Material: Match the fastener to the substrate—wood, metal, plastic, or masonry—to ensure proper thread engagement and avoid splitting or corrosion
• Load: Identify the type of force—static, dynamic, shear, or tension—and select a fastener rated to resist it without deformation or pull-out
• Environment: Use finishes and materials suited to the location—indoor, outdoor, corrosive, or sanitary—to prevent rust, fatigue, or chemical degradation
• Access: Determine if the joint is accessible from one side (use screws) or requires clamping through a hole (use bolt and nut assemblies)

6. What causes fastener failure?

Fastener failure occurs when the mechanical or environmental demands exceed the fastener’s capacity, or when installation or material choices introduce hidden risks. Common causes include:

• Over- or under-tightening – Excess torque can stretch or shear fasteners; under-torque leads to joint loosening and movement
• Galvanic corrosion – Dissimilar metals in contact (e.g., stainless bolt in aluminum) create electrochemical reactions that degrade material
• Thread stripping – Occurs when threads are overdriven, misaligned, or cut into soft or undersized substrates
• Vibration loosening – Repeated motion can back off nuts or screws unless locking features (e.g., lock washers, threadlocker) are used
• Incompatible finishes or materials – Using indoor-rated finishes outdoors, or mismatched coatings, can accelerate rust, fatigue, or joint failure

7. Are fasteners standardized?

Yes. Fastener standards define the material, strength, dimensions, and environmental compliance required for safe and consistent use across industries. These standards apply when:

• Project specifications or building codes require certified fasteners
• Assemblies involve structural, mechanical, or electrical components
• Environmental or international compliance is necessary

Common standards include:

• ASTM – Defines material properties, coatings, and mechanical performance for structural and industrial fasteners
• SAE – Classifies fasteners by strength grade (e.g., Grade 2, 5, 8) for automotive and mechanical use
• ISO – Specifies metric dimensions, thread pitch, and tolerances for global compatibility
• RoHS – Restricts hazardous substances (e.g., lead, cadmium) in fasteners used in electronics and green building

Screws

Wood Screw

A tapered, coarse-threaded fastener designed to bite into wood without the need for a nut. Typically features a flat or oval head for flush or decorative finishes.

Common Use: Framing, cabinetry, trim installation

Finish: Zinc-plated, brass, black oxide

Installation Method: Driven with screwdriver or drill; pilot hole recommended in hardwood

Load Type / Force Resistance: Moderate shear and pull-out resistance

Thread Type / Engagement: Coarse thread; partial thread for clamping

Failure Mode / Risk Flags: Splitting in hardwood, thread strip-out if overdriven

Substrate Compatibility: Wood, plywood, MDF

Machine Screw

A uniform-threaded fastener used with tapped holes or nuts. Available in multiple head styles and drive types for metal-to-metal or metal-to-plastic fastening.

Common Use: Electrical enclosures, metal panels, junction boxes

Finish: Zinc-plated, stainless steel, black oxide

Installation Method: Inserted into tapped hole or through-hole with nut; torque-controlled

Load Type / Force Resistance: High tensile and shear when paired with nut

Thread Type / Engagement: Fine or standard machine thread; full engagement required

Failure Mode / Risk Flags: Cross-threading, loosening under vibration

Substrate Compatibility: Metal, plastic, composite

Sheet Metal Screw

A sharp-pointed, self-tapping fastener designed to pierce and secure thin metal or plastic. Often used in HVAC and appliance assembly.

Common Use: HVAC ductwork, appliance assembly

Finish: Zinc-plated, stainless steel

Installation Method: Driven directly into thin metal or plastic; may self-tap

Load Type / Force Resistance: Light to moderate shear; limited tensile

Thread Type / Engagement: Sharp, self-tapping thread; partial or full

Failure Mode / Risk Flags: Strip-out in thin gauge, over-tightening deformation

Substrate Compatibility: Sheet metal, plastic housings

Self-Tapping Screw

A hardened fastener that forms its own mating threads as it drives into metal, plastic, or composite materials. Eliminates the need for pre-threading.

Common Use: Electrical boxes, conduit straps, metal framing

Finish: Zinc-plated, case-hardened

Installation Method: Driven with drill or impact driver; no pre-threading required

Load Type / Force Resistance: Moderate shear and vibration resistance

Thread Type / Engagement: Thread-cutting or thread-forming; full engagement critical

Failure Mode / Risk Flags: Thread collapse in brittle substrates, overtightening

Substrate Compatibility: Metal, plastic, composite

Drywall Screw

A bugle-headed fastener designed for securing gypsum board to wood or metal studs. Typically features a sharp point and fine or coarse thread.

Common Use: Drywall-to-stud fastening

Finish: Black phosphate

Installation Method: Driven with drywall bit; no pilot hole needed

Load Type / Force Resistance: Light shear; minimal pull-out resistance

Thread Type / Engagement: Coarse thread for wood studs, fine for metal

Failure Mode / Risk Flags: Paper tear-out, overdrive crater

Substrate Compatibility: Gypsum board, wood studs, metal studs

Pan Head Screw

A rounded, low-profile screw with a flat bearing surface under the head. Common in electrical and appliance applications where flush mounting is not required.

Common Use: Electrical boxes, appliance panels, metal brackets

Finish: Zinc-plated, stainless steel, black oxide

Installation Method: Driven with Phillips or Torx driver; flush or surface-mounted

Load Type / Force Resistance: Light to moderate shear; low pull-through risk

Thread Type / Engagement: Machine or self-tapping thread; full engagement preferred

Failure Mode / Risk Flags: Head stripping, thread mismatch

Substrate Compatibility: Metal, plastic, composite

Truss Head Screw

A wide, low-profile screw head designed to maximize surface coverage and reduce pull-through. Often used in HVAC and light-gauge sheet metal.

Common Use: HVAC duct covers, light-gauge sheet metal, plastic panels

Finish: Zinc-plated, stainless steel

Installation Method: Driven with Phillips or square driver; surface-mounted

Load Type / Force Resistance: Light shear; high surface coverage

Thread Type / Engagement: Coarse or self-tapping thread

Failure Mode / Risk Flags: Head deformation, pull-through in soft materials

Substrate Compatibility: Sheet metal, plastic, composite

Socket Head Cap Screw

A high-strength fastener with a cylindrical head and internal hex drive. Used in precision assemblies where space is limited and torque control is critical.

Common Use: Machinery, robotics, automotive assemblies

Finish: Black oxide, stainless steel, alloy steel

Installation Method: Driven with Allen wrench; torque-controlled

Load Type / Force Resistance: High tensile and shear

Thread Type / Engagement: Fine or standard machine thread; full engagement required

Failure Mode / Risk Flags: Thread galling, over-torque fracture

Substrate Compatibility: Metal, composite

Set Screw (Grub Screw)

A headless screw used to secure one object within or against another. Common in rotating assemblies and shaft retention.

Common Use: Shaft collars, pulleys, knobs, gear retention

Finish: Black oxide, stainless steel

Installation Method: Driven with Allen wrench; recessed installation

Load Type / Force Resistance: Axial retention; light shear

Thread Type / Engagement: Fine thread; full engagement required

Failure Mode / Risk Flags: Loosening under vibration, thread wear

Substrate Compatibility: Metal, composite

Thread-Cutting Screw

A self-tapping screw that removes material to form threads in pre-drilled holes. Ideal for plastics and thin metals.

Common Use: Plastic housings, light-gauge metal, electrical enclosures

Finish: Zinc-plated, stainless steel

Installation Method: Driven with drill or screwdriver; requires pilot hole

Load Type / Force Resistance: Moderate shear and pull-out

Thread Type / Engagement: Thread-cutting; full engagement required

Failure Mode / Risk Flags: Material cracking, thread collapse

Substrate Compatibility: Plastic, metal, composite

Roofing Screw

A self-drilling screw with a hex washer head and bonded sealing washer. Designed to create a watertight seal in roofing and siding applications.

Common Use: Metal roofing panels, siding, outdoor enclosures

Finish: Zinc-plated, ceramic-coated, stainless steel

Installation Method: Driven with hex driver; sealing washer compresses under head

Load Type / Force Resistance: Moderate shear; high leak resistance

Thread Type / Engagement: Self-drilling or self-tapping; full engagement preferred

Failure Mode / Risk Flags: Seal degradation, overdrive crushing washer

Substrate Compatibility: Metal panels, wood purlins, composite roofing

Deck Screw

A corrosion-resistant screw designed for outdoor wood-to-wood fastening. Typically features a bugle head and coarse thread for treated lumber.

Common Use: Deck boards, railing systems, outdoor wood structures

Finish: Ceramic-coated, stainless steel

Installation Method: Driven with square or Torx bit; pilot hole optional in hardwood

Load Type / Force Resistance: Moderate shear and pull-out resistance

Thread Type / Engagement: Coarse thread; partial or full depending on length

Failure Mode / Risk Flags: Head snapping, thread strip-out in dense wood

Substrate Compatibility: Pressure-treated lumber, cedar, composite decking

Bolts

Hex Bolt

A six-sided head bolt used for structural and mechanical fastening. Common in steel framing and machinery where high clamping force is required.

Common Use: Steel framing, machinery, anchor plates

Finish: Hot-dip galvanized, zinc-plated, stainless steel

Installation Method: Inserted through pre-drilled hole; tightened with wrench or impact driver

Load Type / Force Resistance: High tensile and shear resistance

Thread Type / Engagement: Coarse or fine thread; full engagement with nut required

Failure Mode / Risk Flags: Over-tightening, thread galling, corrosion mismatch

Substrate Compatibility: Steel, wood, concrete (with anchors)

Carriage Bolt

A rounded head bolt with a square neck that locks into wood to prevent rotation. Used in wood-to-wood or wood-to-metal fastening.

Common Use: Decking, fence posts, playground equipment

Finish: Zinc-plated, galvanized

Installation Method: Inserted into pre-drilled hole; square neck locks into wood

Load Type / Force Resistance: Moderate shear and pull-through resistance

Thread Type / Engagement: Coarse thread; nut required

Failure Mode / Risk Flags: Neck spin-out, pull-through in soft wood

Substrate Compatibility: Wood, composite, metal (with washer)

Lag Bolt

A heavy-duty wood fastener with a hex head, designed for high-load structural applications. Often used without a nut.

Common Use: Ledger boards, heavy timber, structural wood joints

Finish: Hot-dip galvanized, zinc-plated

Installation Method: Driven into wood with wrench; pilot hole recommended

Load Type / Force Resistance: High pull-out and shear resistance

Thread Type / Engagement: Coarse thread; partial or full depending on length

Failure Mode / Risk Flags: Wood splitting, thread strip-out

Substrate Compatibility: Wood, masonry (with shield anchor)

Eye Bolt

A bolt with a looped head used for lifting, anchoring, or suspending loads. Available in open or closed eye styles.

Common Use: Rigging, cable suspension, tie-downs

Finish: Galvanized, stainless steel

Installation Method: Inserted through hole; secured with nut or embedded in concrete

Load Type / Force Resistance: Tension and axial load bearing

Thread Type / Engagement: Coarse or machine thread; full engagement required

Failure Mode / Risk Flags: Bending under side load, thread pull-out

Substrate Compatibility: Wood, metal, concrete (with anchor)

U-Bolt

A U-shaped bolt used to secure pipe, conduit, or round objects to a surface. Typically includes two nuts and washers.

Common Use: Pipe hangers, cable trays, exhaust systems

Finish: Zinc-plated, galvanized

Installation Method: Inserted around pipe; secured with nuts and washers

Load Type / Force Resistance: Clamp force and vibration resistance

Thread Type / Engagement: Machine thread; nut required

Failure Mode / Risk Flags: Thread loosening, deformation under load

Substrate Compatibility: Pipe, conduit, round bar, structural steel

Flange Bolt

A bolt with an integrated washer-like flange under the head to distribute load and resist loosening. Often serrated for grip.

Common Use: Automotive assemblies, machinery, sheet metal fastening

Finish: Zinc-plated, black oxide, stainless steel

Installation Method: Driven with socket or wrench; flange grips surface without separate washer

Load Type / Force Resistance: High shear and vibration resistance

Thread Type / Engagement: Coarse or fine machine thread; full engagement required

Failure Mode / Risk Flags: Surface damage from serrated flange, over-torque deformation

Substrate Compatibility: Metal, plastic, composite

Nuts

Hex Nut

A standard six-sided nut used for general-purpose fastening. Designed to pair with bolts or threaded studs for secure clamping.

Common Use: Machinery, framing, bracket attachment

Finish: Zinc-plated, galvanized, stainless steel

Installation Method: Threaded onto bolt or stud; torque applied

Load Type / Force Resistance: High tensile and shear when paired with bolt

Thread Type / Engagement: Coarse or fine; full engagement required

Failure Mode / Risk Flags: Thread stripping, loosening under vibration

Substrate Compatibility: Metal, wood (with bolt), concrete (with anchor)

Lock Nut

A vibration-resistant nut that prevents loosening through nylon inserts or deformed threads. Used in dynamic assemblies.

Common Use: Vibration zones, rotating equipment, HVAC mounts

Finish: Zinc-plated, stainless steel

Installation Method: Threaded onto bolt; resists backing off

Load Type / Force Resistance: Vibration and dynamic load resistance

Thread Type / Engagement: Coarse or fine; full engagement critical

Failure Mode / Risk Flags: Nylon degradation, overtightening

Substrate Compatibility: Metal, wood, composite

Wing Nut

A hand-tightened nut with wing-like projections for tool-free adjustment. Ideal for temporary or adjustable assemblies.

Common Use: Temporary panels, signage, hand-adjustable fixtures

Finish: Zinc-plated, stainless steel

Installation Method: Hand-tightened; no tools required

Load Type / Force Resistance: Light-duty clamping

Thread Type / Engagement: Coarse thread; partial or full

Failure Mode / Risk Flags: Loosening under vibration, thread wear

Substrate Compatibility: Metal, plastic, wood

Cap Nut (Acorn Nut)

A decorative and protective nut with a domed top that covers exposed threads. Used for safety and aesthetics.

Common Use: Furniture, exposed bolt ends, safety covers

Finish: Chrome-plated, zinc-plated, stainless steel

Installation Method: Threaded onto exposed bolt; hand or tool-tightened

Load Type / Force Resistance: Light-duty tension

Thread Type / Engagement: Coarse thread; partial engagement typical

Failure Mode / Risk Flags: Cosmetic damage, thread mismatch

Substrate Compatibility: Metal, wood

Flange Nut

A nut with an integrated washer base to distribute load and resist loosening. Often serrated for grip in vibration zones.

Common Use: Automotive, machinery, sheet metal fastening

Finish: Zinc-plated, serrated stainless steel

Installation Method: Threaded onto bolt; serrations grip surface

Load Type / Force Resistance: Shear and vibration resistance

Thread Type / Engagement: Coarse or fine; full engagement required

Failure Mode / Risk Flags: Surface damage, over-torque

Substrate Compatibility: Metal, plastic, composite

Jam Nut

A thin nut used to lock a standard nut in place. Often used in pairs to prevent rotation or loosening.

Common Use: Shaft assemblies, lockout applications, threaded rod stabilization

Finish: Zinc-plated, stainless steel

Installation Method: Threaded against standard nut; tightened to lock position

Load Type / Force Resistance: Axial retention; vibration resistance

Thread Type / Engagement: Coarse or fine; partial engagement typical

Failure Mode / Risk Flags: Thread wear, improper locking sequence

Substrate Compatibility: Metal, composite

Coupling Nut

A long, internally threaded nut used to join two male-threaded components. Common in threaded rod extensions.

Common Use: Threaded rod extensions, conduit unions, mechanical linkages

Finish: Zinc-plated, stainless steel

Installation Method: Threaded onto both ends; torque applied

Load Type / Force Resistance: Axial tension and compression

Thread Type / Engagement: Coarse or fine; full engagement required

Failure Mode / Risk Flags: Misalignment, thread mismatch

Substrate Compatibility: Metal, conduit, rod assemblies

Castle Nut

A slotted nut designed to accept a cotter pin for mechanical locking. Used in critical assemblies requiring fail-safe retention.

Common Use: Axle assemblies, steering linkages, mechanical pivots

Finish: Zinc-plated, stainless steel

Installation Method: Threaded onto bolt; aligned with hole and pinned

Load Type / Force Resistance: Axial tension; mechanical lockout

Thread Type / Engagement: Coarse thread; full engagement required

Failure Mode / Risk Flags: Pin shear, misalignment, slot deformation

Substrate Compatibility: Metal, mechanical assemblies

Washers

Flat Washer

A thin, flat disc used to distribute load and prevent surface damage under bolt heads or nuts. Also helps cover oversized holes.

Common Use: Bolt assemblies, wood-to-metal interfaces, oversized holes

Finish: Zinc-plated, stainless steel, galvanized

Installation Method: Placed under bolt head or nut; passive component

Load Type / Force Resistance: Load distribution; minimal force resistance

Thread Type / Engagement: N/A

Failure Mode / Risk Flags: Deformation under high torque, corrosion

Substrate Compatibility: Wood, metal, plastic

Lock Washer (Split)

A helical-shaped washer that compresses under torque to resist loosening. Common in vibration-prone assemblies.

Common Use: Motor mounts, vibration zones, rotating assemblies

Finish: Zinc-plated, black oxide

Installation Method: Placed under nut or bolt head; compresses under torque

Load Type / Force Resistance: Vibration resistance

Thread Type / Engagement: N/A

Failure Mode / Risk Flags: Flattening under over-torque, loss of tension

Substrate Compatibility: Metal, plastic

Fender Washer

A washer with a large outer diameter for load distribution across soft materials or oversized holes. Used where surface area coverage is critical.

Common Use: Drywall anchors, plastic panels, thin sheet metal

Finish: Zinc-plated, stainless steel

Installation Method: Placed under bolt or screw head; distributes load

Load Type / Force Resistance: Load distribution; minimal tension

Thread Type / Engagement: N/A

Failure Mode / Risk Flags: Bending, pull-through

Substrate Compatibility: Plastic, drywall, soft wood

Sealing Washer

A washer bonded with rubber or neoprene to create a watertight seal under fasteners. Used in roofing and outdoor enclosures.

Common Use: Roofing, outdoor enclosures, plumbing

Finish: Stainless steel with bonded seal

Installation Method: Compressed under bolt or screw head

Load Type / Force Resistance: Leak resistance; light tension

Thread Type / Engagement: N/A

Failure Mode / Risk Flags: Seal degradation, over-compression

Substrate Compatibility: Metal, plastic, roofing membrane

Belleville Washer (Spring Washer)

A conical washer that provides spring tension under load. Used to maintain preload in dynamic assemblies.

Common Use: Electrical terminals, thermal expansion joints, dynamic assemblies

Finish: Black oxide, stainless steel

Installation Method: Placed under bolt or nut; compresses under load

Load Type / Force Resistance: Axial tension and vibration resistance

Thread Type / Engagement: N/A

Failure Mode / Risk Flags: Fatigue, flattening

Substrate Compatibility: Metal, composite

External Tooth Lock Washer

A washer with outward-facing teeth that bite into the mounting surface to resist rotation. Used under bolt heads or nuts.

Common Use: Electrical connections, sheet metal fastening

Finish: Zinc-plated, stainless steel

Installation Method: Placed under fastener; teeth grip surface

Load Type / Force Resistance: Rotation resistance; light vibration resistance

Thread Type / Engagement: N/A

Failure Mode / Risk Flags: Surface scoring, tooth deformation

Substrate Compatibility: Metal, plastic

Internal Tooth Lock Washer

A washer with inward-facing teeth that grip the fastener shaft to resist loosening. Used in tight clearance applications.

Common Use: Electronics, small enclosures, precision assemblies

Finish: Zinc-plated, stainless steel

Installation Method: Placed under fastener; teeth grip shaft

Load Type / Force Resistance: Rotation resistance; light vibration resistance

Thread Type / Engagement: N/A

Failure Mode / Risk Flags: Tooth wear, ineffective grip on smooth surfaces

Substrate Compatibility: Metal, plastic, composite

Concrete & Masonry Anchors

Wedge Anchor

An expansion anchor with a threaded stud and wedge clip that locks into concrete as the nut is tightened. Used for heavy-duty structural applications.

Common Use: Structural steel base plates, racking systems, seismic bracing

Finish: Zinc-plated, hot-dip galvanized, stainless steel

Installation Method: Inserted into drilled hole; tightened to expand wedge

Load Type / Force Resistance: High tension and shear

Thread Type / Engagement: Machine thread; full engagement with nut

Failure Mode / Risk Flags: Pull-out under vibration, edge breakout

Substrate Compatibility: Concrete

Sleeve Anchor

A pre-assembled anchor with an expanding sleeve that grips the walls of the hole as the bolt is tightened. Suitable for medium-duty loads.

Common Use: Handrails, light posts, electrical boxes

Finish: Zinc-plated, stainless steel

Installation Method: Inserted into hole; sleeve expands as bolt is tightened

Load Type / Force Resistance: Moderate shear and pull-out

Thread Type / Engagement: Machine thread; nut required

Failure Mode / Risk Flags: Sleeve collapse, over-expansion

Substrate Compatibility: Concrete, brick, block

Drop-In Anchor

An internally threaded anchor set flush into concrete. Requires a setting tool to expand the internal sleeve and lock in place.

Common Use: Overhead supports, threaded rod suspension, mechanical hangers

Finish: Zinc-plated, stainless steel

Installation Method: Inserted into drilled hole; expanded with setting tool

Load Type / Force Resistance: High tension; axial loads

Thread Type / Engagement: Internal machine thread; bolt or rod required

Failure Mode / Risk Flags: Improper setting depth, thread stripping

Substrate Compatibility: Concrete

Strike Anchor (Hammer-Drive Anchor)

An expansion anchor driven with a hammer to set the wedge. Used for light-duty applications in concrete and brick.

Common Use: Light-duty fixtures, pipe clamps, electrical boxes

Finish: Zinc-plated

Installation Method: Inserted into hole; driven with hammer

Load Type / Force Resistance: Light shear and pull-out

Thread Type / Engagement: Pre-formed stud; no threading

Failure Mode / Risk Flags: Overdriving, poor expansion

Substrate Compatibility: Concrete, brick

Concrete Screw (Tapcon-style)

A hardened threaded fastener that cuts its own threads into concrete or masonry. Requires a pilot hole and is installed without an anchor.

Common Use: Furring strips, conduit straps, electrical boxes

Finish: Blue corrosion-resistant coating, stainless steel

Installation Method: Driven into pre-drilled hole with impact driver

Load Type / Force Resistance: Moderate tension and shear

Thread Type / Engagement: Thread-cutting; full engagement required

Failure Mode / Risk Flags: Thread strip-out, edge breakout

Substrate Compatibility: Concrete, brick, block

Lag Shield Anchor

An expandable sleeve anchor used with lag bolts in masonry. Expands as the bolt is driven, locking into the substrate.

Common Use: Heavy-duty wood-to-concrete fastening, ledger boards, equipment mounting

Finish: Zinc alloy or galvanized

Installation Method: Inserted into pre-drilled hole; expands as lag bolt is driven

Load Type / Force Resistance: High pull-out and shear

Thread Type / Engagement: Internal expansion; lag bolt required

Failure Mode / Risk Flags: Shield rotation, hole oversizing

Substrate Compatibility: Concrete, brick, block

Plastic Expansion Anchor

A general-purpose anchor that expands when a screw is driven into it. Used for light-duty fastening in masonry and drywall.

Common Use: Light-duty wall hangings in brick, block, or concrete

Finish: Unfinished plastic

Installation Method: Inserted into pre-drilled hole; expands with screw

Load Type / Force Resistance: Light tension

Thread Type / Engagement: Screw-driven expansion

Failure Mode / Risk Flags: Pull-out, cracking in brittle substrates

Substrate Compatibility: Concrete, brick, drywall, block