Do Bolts Need Washers? When to Use—and When Not to Use—Washers in Bolted Joints

Do all bolts need washers?

No.

A washer is not automatically required simply because a joint contains a bolt and nut.

In a properly engineered bolted joint, every component should have a defined function. A washer may be required to provide a controlled bearing interface, 

increase bearing area, bridge an appropriate hole geometry, meet a fastener-system specification, provide electrical isolation, support sealing, add controlled spring compliance or perform another specific function.

In other joints, the bolt head, nut, flange or surrounding joint geometry may already provide the required bearing interface.

The correct question is therefore not:

“Should every bolt have a washer?”

It is:

“What function would the washer perform in this joint?”

A practical engineering decision path is:

Joint Geometry → Bearing Interface → Parent Material → Hole Geometry → Preload → Environment → Special Function → Washer Required? → Washer Type → Standard → Validation → RFQ

JUXIN FASTENERS supports OEM sourcing of flat washers, spring washers, disc spring washers, locking fasteners, bolts, nuts,

 screws and custom fastening components for automotive equipment, EV systems, AI data centers, power electronics, electrical equipment, industrial machinery, HVAC, telecommunications, automation and heavy equipment.

What Does a Washer Actually Do in a Bolted Joint?

The term washer describes a broad family of components.

Different washer types perform different functions.

Depending on the design, a washer may be selected to:

• increase bearing area;

• reduce localized bearing pressure;

• protect an appropriate mating surface;

• provide a defined bearing interface;

• support selected oversized or slotted holes;

• meet a high-strength fastener-system requirement;

• provide controlled elastic compliance;

• provide a specific locking mechanism;

• provide electrical isolation;

• contribute to an engineered sealing interface;

• accommodate special geometry.

This leads to an important engineering principle:

Washer Required? → Determine the Function First

Are Washers Mandatory With Bolts?

Not universally.

A bolt can be used:

• with a washer under the head;

• with a washer under the nut;

• with washers on both sides;

• without a separate washer.

The correct configuration depends on:

• fastener geometry;

• bearing surface;

• parent material;

• hole geometry;

• clamp load;

• tightening method;

• applicable standard;

• customer drawing;

• service environment.

There is no universal rule that every threaded fastener requires a separate washer.

Why Are Flat Washers Used?

A plain flat washer primarily modifies the bearing interface beneath the bolt head or nut.

Potential functions include:

Increasing Bearing Area

A washer can increase the area through which clamp load enters the parent material.

Reducing Localized Indentation

This can be useful where the parent material is relatively soft or susceptible to local deformation.

Providing a Controlled Bearing Surface

The washer can create a defined interface beneath the rotating fastener component.

Supporting Appropriate Hole Geometry

Certain washer geometries can provide support around appropriately designed clearance holes, enlarged holes or slots.

However:

Flat Washer ≠ Locking Device

and:

Flat Washer ≠ Vibration Damper

and:

Flat Washer ≠ Automatic Sealing Element

Those are separate engineering functions.

When a Flat Washer May Be Needed

A flat washer should be considered when the joint requires a function that the existing fastener bearing surface does not adequately provide.

Common engineering situations include the following.

Soft Parent Materials

When the fastener bears against relatively soft material, localized bearing pressure can become important.

Potential parent materials include:

• aluminum;

• some engineering plastics;

• thin sheet;

• selected composites.

A suitable washer can increase bearing area and reduce localized pressure.

However:

Larger Washer ≠ Automatically Safe Joint

The engineer must still evaluate:

• parent-material strength;

• washer stiffness;

• clamp load;

• hole geometry;

• creep or relaxation where applicable.

Thin Sheet Metal

Thin sheet can deform around a concentrated fastener bearing area.

Depending on the joint, an appropriately sized washer can help spread load over a larger region.

But washer selection cannot correct every thin-sheet design problem.

Engineers may also need to evaluate:

• sheet bending;

• pull-through;

• hole deformation;

• edge distance;

• local buckling;

• clamp load.

Aluminum Components

Aluminum assemblies may require particular attention to:

• bearing pressure;

• surface indentation;

• washer diameter;

• washer thickness;

• galvanic compatibility;

• coating;

• clamp load.

A flat washer can help create a more suitable bearing interface, but the complete joint must still be engineered.

Polymer Components

Polymers can introduce:

• creep;

• stress relaxation;

• temperature sensitivity;

• local crushing.

A larger washer may reduce local bearing pressure.

It does not eliminate polymer creep.

Therefore:

Washer Area ↑ ≠ Creep Eliminated

Long-term preload retention must be considered separately.

When Surface Protection Matters

Direct rotation of a nut or bolt head against a component can affect:

• painted surfaces;

• plated surfaces;

• precision-machined surfaces;

• selected soft materials.

A washer may change the contact interface and reduce certain forms of direct surface damage.

But it should not be described as guaranteeing surface protection.

The actual result depends on:

• washer finish;

• surface finish;

• bearing pressure;

• rotation during tightening;

• coating properties.

Frequent Assembly and Disassembly

Repeated maintenance can change the condition of a bearing surface.

Where the design permits it, a replaceable washer may provide a controlled interface between the fastener and the component.

However, repeated disassembly can also affect:

• threads;

• coatings;

• prevailing-torque features;

• locking compounds;

• washer condition.

The entire fastening system should be considered.

Do High-Strength Bolts Need Washers?

Sometimes—but the answer depends on the fastener system and joint specification.

High-strength bolts can generate substantial clamp loads.

The bearing interface must support those loads without unacceptable deformation.

Depending on the application, a hardened washer may be specified beneath:

• the bolt head;

• the nut;

• both;

• neither.

The applicable fastener or structural specification should control the requirement.

Do not substitute a general-purpose commodity washer solely because its nominal diameter fits the bolt.

For high-strength fastening systems, see High-Strength Bolts & Nuts: Engineering Selection Guide.

Hardened Washers Are Not Generic Flat Washers

Washer hardness becomes important when substantial clamp load is transferred through the bearing interface.

ASTM F436/F436M is one example of a specification for hardened steel washers within its defined mechanical and structural applications.

It should not be treated as a universal flat-washer specification.

The key distinction is:

Plain Washer Geometry ≠ Hardened Washer Requirement

A washer can fit dimensionally and still be mechanically unsuitable for a particular high-load joint.

ISO 7089 Plain Washers

ISO 7089 specifies:

Plain washers — Normal series — Product grade A

within its defined scope.

ISO 7089:2000 remains the currently published edition, while a future revision is under development.

This standard can provide a defined metric plain-washer geometry for applicable joints.

But specifying ISO 7089 does not answer every engineering question.

The joint still needs appropriate:

• bearing area;

• hardness;

• parent-material compatibility;

• surface finish;

• clamp-load capability.

Normal, Small, Large and Extra-Large Washer Series

Metric plain washers are available in different dimensional series under applicable ISO standards.

Depending on the standard, these can include:

• small series;

• normal series;

• large series;

• extra-large series.

The required series should follow the joint design.

A larger OD may increase the potential bearing footprint, but:

Larger OD ≠ Automatically Better

Washer thickness, stiffness, available space and parent-material behavior also matter.

Do Oversized Holes Need Washers?

Oversized holes can require specific washer geometry.

But the solution should not be:

“Just use a bigger washer.”

The washer must be appropriate for:

• hole diameter;

• fastener diameter;

• washer OD;

• washer ID;

• washer thickness;

• clamp load;

• applicable connection standard.

In structural applications, oversized holes can be governed by specific design and installation requirements.

Follow the applicable structural system rather than improvising a washer arrangement.

Do Slotted Holes Need Washers?

Slotted holes create different bearing conditions from ordinary round clearance holes.

The engineer may need to evaluate:

• slot width;

• slot length;

• adjustment range;

• washer OD;

• washer thickness;

• washer stiffness;

• clamp load;

• surrounding geometry.

The washer should provide the required support throughout the intended assembly position.

Should Multiple Flat Washers Be Stacked Over a Slot?

Stacking several ordinary washers is not a universal engineering solution for an oversized or slotted hole.

Multiple interfaces can change:

• stack height;

• stiffness;

• embedment behavior;

• tightening behavior.

Where a special plate washer, thick washer or other defined component is required, use the engineered component specified for the joint.

When a Washer May Not Be Required

A separate washer may not be necessary when the required function is already provided by the fastener or joint design.

Several examples illustrate this principle.

Flange Bolts and Flange Nuts

A flange bolt or flange nut incorporates an enlarged bearing surface.

Depending on the joint, this can reduce or eliminate the need for a separate plain washer.

But:

Flange Fastener ≠ Never Use Washer

A separate washer may still be required if:

• the drawing specifies one;

• the parent material requires a different bearing interface;

• the hole geometry requires additional support;

• a special washer function is required.

The integrated flange must be evaluated as part of the complete joint.

Fasteners With Integrated Washer Faces

Some screws and bolts incorporate:

• washer heads;

• flange heads;

• enlarged bearing faces.

These designs can provide a bearing footprint without a separate loose washer.

This can also simplify assembly and reduce component count.

However, the integrated geometry must meet the actual bearing requirement.

SEMS and Captive Washer Assemblies

Some screws are supplied with captive washers.

These assemblies can provide:

• reduced loose-part handling;

• controlled component presence;

• faster assembly;

• reduced risk of omitted washers.

The washer is retained on the screw but still performs its own defined mechanical function.

A captive washer does not automatically mean the joint requires locking.

Do Shear Connections Need Washers?

The old version of this article suggested that shear-type connections generally do not need washers.

That is too broad.

Whether a connection transfers load primarily through:

• shear;

• bearing;

• friction;

• tension;

• a combination of these

does not by itself determine whether a washer is required.

Washer requirements depend on the complete fastener system and connection specification.

Therefore:

Shear Connection ≠ Automatically No Washer

Follow the applicable design standard and drawing.

Do Bolts in Clearance Holes Always Need Washers?

No.

A clearance hole alone does not automatically require a washer.

The engineer should evaluate:

• fastener bearing diameter;

• hole diameter;

• parent material;

• clamp load;

• applicable standard.

A washer becomes appropriate when it performs a necessary function.

Do Bolts in Tapped Holes Need Washers?

A screw or bolt installed into a tapped hole may or may not use a washer beneath its head.

The decision depends on:

• head geometry;

• parent material;

• bearing surface;

• required clamp load;

• service requirements.

The absence of a nut does not determine the washer requirement.

Washer Under the Nut or Bolt Head?

Washers can be specified:

• under the nut;

• under the bolt head;

• under both.

The correct location depends on which bearing interface requires control.

If one component rotates during tightening, its bearing interface may also affect tightening friction.

Therefore, washer placement can influence torque-preload behavior.

Why Washer Location Can Affect Tightening

Applied tightening torque is consumed largely by friction in:

• the threads;

• the bearing interface beneath the rotating component.

Adding, removing or changing a washer can alter that interface.

This means:

Changing the Washer Can Change the Torque–Preload Relationship

For critical joints, tightening should be validated using the actual:

• fastener;

• washer;

• coating;

• lubricant;

• parent surface.

Flat Washers Do Not Automatically Improve Sealing

A plain steel flat washer is not a dedicated sealing component.

If sealing is required, the joint may need:

• bonded sealing washer;

• elastomeric sealing element;

• gasket;

• O-ring;

• dedicated sealing fastener.

Therefore:

Flat Washer ≠ Sealing Washer

Enclosure-level IP performance must be validated at the assembly level.

Flat Washers Do Not Automatically Damp Vibration

A plain washer does not inherently function as a vibration damper.

Its primary role is generally associated with the bearing interface.

If vibration damping is required, use a component or system specifically designed for energy dissipation or isolation.

Do Spring Washers Prevent Bolts From Loosening?

This requires a more careful answer than:

“Yes, because they add spring force.”

A conventional split spring washer can influence the interface and rotational resistance.

However, it should not be treated as a universal solution for vibration-induced self-loosening.

Its effectiveness depends on:

• preload;

• joint movement;

• surface conditions;

• fastener geometry;

• loading.

ASME terminology itself should not be interpreted as guaranteeing indefinite locking simply because the product is called a “spring-lock washer.”

Spring Washer Force Is Not Bolt Preload

The bolt develops preload when tightened.

A split spring washer can generate elastic reaction as it compresses.

These are not the same thing.

Therefore:

Spring Washer Force ≠ Bolt Preload

This distinction is especially important in high-preload joints.

Spring Washers Are Not Disc Springs

A conventional split spring washer should not be confused with a Belleville disc spring.

A properly engineered disc spring can provide a defined load-deflection relationship and can be used individually or in designed stacks.

A split spring washer serves a different purpose.

Therefore:

Split Spring Washer ≠ Disc Spring Preload Compensation System

When Should a Spring Washer Be Used?

A split spring washer may remain appropriate where:

• a controlled drawing specifies it;

• legacy equipment uses it;

• the customer specification requires it;

• its performance is acceptable for the validated assembly.

For a new joint exposed to significant vibration, engineers should identify the actual loosening mechanism before automatically specifying a split spring washer.

Alternatives to Conventional Spring Washers

Depending on the application, engineers may evaluate:

• prevailing-torque locknuts;

• nylon-insert locknuts;

• all-metal locknuts;

• engineered locking washer systems;

• thread-locking compounds;

• positive mechanical locking.

For one common prevailing-torque solution, see Nylon Insert Locknuts for Anti-Vibration Applications.

The correct locking method depends on the joint.

Do Disc Spring Washers Have a Different Function?

Yes.

Disc springs, also called Belleville springs or Belleville washers, are conical elastic elements.

They can be selected around:

• axial load;

• deflection;

• available space;

• spring rate;

• stacking arrangement.

They should not be grouped mechanically with ordinary flat washers or conventional split spring-lock washers.

Does Every Vibration-Prone Bolt Need a Lock Washer?

No.

The better question is:

Why is the joint loosening?

Possible mechanisms include:

• insufficient preload;

• transverse joint movement;

• embedment;

• material relaxation;

• thermal effects;

• inappropriate tightening;

• unsuitable locking method.

The locking solution should address the actual failure mechanism.

Preload Loss vs Rotational Loosening

These are different engineering problems.

Preload Loss

Clamp force decreases.

Possible causes include:

• embedment;

• creep;

• relaxation;

• gasket compression;

• thermal effects.

Rotational Self-Loosening

The threaded fastener physically rotates.

A locking feature designed to resist rotation may not correct material relaxation.

Diagnose the failure before selecting the hardware.

Do Stainless Steel Bolts Need Stainless Steel Washers?

Not automatically, although compatible stainless components are common in many assemblies.

Material selection should consider:

• corrosion environment;

• mechanical properties;

• galvanic interaction;

• galling risk;

• customer specification.

Stainless steel is not corrosion-proof.

The grade and complete material combination matter.

Electrical Isolation Washers

A metallic washer may be unsuitable where electrical isolation is required.

Engineering-plastic washers can be manufactured from materials such as:

• PA6;

• PA66;

• POM;

• PP;

• PC;

• PVDF;

• PEEK

depending on the application.

But:

Plastic Washer ≠ Automatically UL94 V-0

and:

Plastic Washer ≠ Automatically Electrical-Safety Certified

The actual material grade and certification requirements must be specified.

Do Electrical Grounding Connections Need Special Washers?

Potentially.

Electrical bonding and grounding involve electrical-contact requirements beyond ordinary mechanical clamping.

A generic flat washer should not automatically be described as a grounding component.

If electrical continuity is part of the joint function, evaluate:

• contact resistance;

• coatings;

• oxide layers;

• surface preparation;

• applicable electrical requirements.

Automotive Applications

Washer requirements in automotive equipment vary by joint.

Potential applications include:

• brackets;

• auxiliary equipment;

• electronic housings;

• body-related hardware;

• thermal-management equipment.

Safety-critical joints require customer-specific engineering and validation.

Do not apply a universal washer rule across all automotive fasteners.

EV Battery and Power Electronics Equipment

Potential washer applications include:

• battery-related structures;

• power electronics;

• cooling equipment;

• service panels;

• equipment brackets.

The washer may provide a mechanical bearing function.

It should not automatically be described as providing:

• battery sealing;

• grounding;

• EMI shielding;

• IP protection.

Those are separate engineering requirements.

AI Data Centers and HPC Equipment

AI data centers and HPC infrastructure use threaded fasteners throughout:

• server-related equipment;

• racks;

• cooling systems;

• UPS equipment;

• power-conversion equipment;

• electrical enclosures.

Whether a washer is required depends on the actual joint.

The industry application itself does not determine the washer requirement.

Electrical Equipment and Switchgear

Washers may be used in:

• cabinet structures;

• mounting brackets;

• control panels;

• equipment covers;

• power distribution equipment.

Where electrical bonding is required, that function must be separately specified.

Telecommunications Equipment

Potential applications include:

• equipment cabinets;

• racks;

• mounting structures;

• enclosures.

Thin sheet, coatings and repeated maintenance can make bearing-interface design important.

HVAC Equipment

HVAC equipment can contain:

• fan systems;

• brackets;

• equipment housings;

• compressors;

• control assemblies.

Vibration does not automatically mean every bolt needs a spring washer.

Identify the actual joint requirement first.

Industrial Machinery and Automation

Industrial machinery may expose fasteners to:

• cyclic loading;

• vibration;

• thermal variation;

• repeated maintenance.

The correct solution may involve a flat washer, hardened washer, locking fastener, disc spring or no separate washer.

Heavy Equipment

Construction, mining and agricultural machinery can involve:

• high mechanical loads;

• impact;

• vibration;

• outdoor corrosion;

• contamination.

Washer selection should therefore be coordinated with:

• bolt grade;

• nut grade;

• parent material;

• coating;

• locking strategy.

Medical and Laboratory Equipment

Washers may be used in appropriate non-sterile assemblies such as:

• diagnostic-equipment housings;

• laboratory instruments;

• carts;

• covers;

• internal brackets.

Generic industrial washers should not automatically be described as medically certified, sterile, biocompatible or cleanroom-qualified.

Washer Requirement Decision Matrix

Five Questions to Ask Before Adding a Washer

1. What Problem Is the Washer Solving?

Bearing?

Locking?

Sealing?

Electrical isolation?

Spring compliance?

If the answer is unclear, the washer may simply be present by habit.

2. What Is the Parent Material?

Steel, aluminum, plastic and thin sheet can require very different bearing interfaces.

3. What Is the Hole Geometry?

Normal clearance hole, oversized hole and slot should not automatically use the same washer.

4. What Clamp Load Will the Joint Carry?

High-preload joints can require washer hardness and stiffness appropriate to the fastener system.

5. Does a Standard or Drawing Control the Joint?

If yes, follow it.

Do not casually add or remove washers from a validated controlled assembly.

Common Washer Selection Mistakes

Mistake 1: Putting a Washer Under Every Bolt by Default

Every component should have a defined function.

Mistake 2: Omitting the Washer Because the Bolt Fits

Physical fit does not prove the bearing interface is adequate.

Mistake 3: Assuming a Flange Bolt Never Needs a Washer

The complete joint determines the requirement.

Mistake 4: Assuming Flat Washers Prevent Loosening

Plain washers are primarily bearing-interface components.

Mistake 5: Assuming Flat Washers Seal the Joint

Use an engineered sealing solution where sealing is required.

Mistake 6: Assuming Flat Washers Damp Vibration

They are not generic vibration dampers.

Mistake 7: Using Split Spring Washers for Every Vibration Problem

Identify the actual loosening mechanism.

Mistake 8: Using Ordinary Washers With High-Strength Fasteners Without Checking Hardness

Dimensional fit alone is insufficient.

Mistake 9: Stacking Washers to Cover a Poorly Designed Hole

Use the washer or plate geometry required by the engineering design.

Mistake 10: Changing a Controlled Assembly Without Validation

Adding or removing a washer can alter tightening friction and preload.

Engineer Search Intent

Engineers may search:

• do bolts need washers;

• when should washers be used;

• when are washers required;

• when can washers be omitted;

• washer under bolt head or nut;

• do flange bolts need washers;

• washer for aluminum;

• washer for thin sheet;

• washer for oversized hole;

• washer for slotted hole;

• hardened washer for high-strength bolt;

• do spring washers work.

These searches indicate a design decision, not merely a product-definition question.

Procurement Search Intent

Procurement and supplier-development teams may search:

• industrial washer supplier;

• flat washer manufacturer;

• hardened washer supplier;

• custom washer manufacturer;

• bolt nut washer supplier;

• ISO washer supplier;

• OEM fastener supplier.

The RFQ should begin after the washer function has been defined.

“M12 Washer” Is Not a Complete Industrial Specification

An RFQ that says:

“Need M12 washers.”

can leave many questions unanswered.

Flat washer?

Hardened washer?

Spring washer?

Disc spring?

Sealing washer?

What standard?

What ID, OD and thickness?

What material?

What hardness?

What finish?

What quantity?

A technically controlled RFQ reduces substitution risk and improves quotation accuracy.

Washer and Bolted-Joint RFQ Checklist

For technical and commercial evaluation by JUXIN FASTENERS, provide where applicable:

• 2D drawing;

• physical sample;

• customer part number;

• application;

• applicable standard;

• metric or inch system;

• bolt or screw size;

• thread specification;

• bolt/screw standard;

• bolt/screw property class or grade;

• nut standard and grade where applicable;

• washer function;

• washer type;

• washer standard;

• washer ID;

• washer OD;

• washer thickness;

• washer hardness;

• washer material;

• surface finish;

• coating requirement;

• trivalent chromium requirement where applicable;

• RoHS/REACH requirement where applicable;

• corrosion-test requirement;

• parent material;

• parent-material thickness;

• parent-material hardness where relevant;

• clearance-hole diameter;

• oversized-hole dimensions where applicable;

• slot dimensions where applicable;

• edge distance;

• clamp-load requirement where known;

• tightening method;

• tightening torque where controlled;

• locking requirement;

• sealing requirement;

• electrical-isolation requirement;

• grounding/bonding requirement;

• operating temperature;

• corrosion environment;

• maintenance/disassembly requirement;

• sample quantity;

• production quantity;

• annual demand;

• inspection requirements;

• packaging requirements;

• labeling requirements;

• customer-specific requirements.

Frequently Asked Questions

Does every bolt need a washer?

No.

A washer should be used when it performs a required function or is specified by the applicable standard or controlled drawing.

What is the main purpose of a flat washer?

Its primary function is generally to modify the bearing interface by increasing bearing area or providing a defined surface beneath the bolt head or nut.

Do flange bolts need washers?

Not always.

The integrated flange may provide sufficient bearing area, but the complete joint design determines whether a separate washer is required.

Do high-strength bolts need hardened washers?

They may, depending on the fastener system and applicable specification.

Do not use an ordinary washer as a substitute where a hardened washer is required.

Does a bolt in a shear connection need a washer?

The fact that a connection transfers shear does not by itself determine the washer requirement.

Follow the applicable connection design and fastener specification.

Should I use a washer on aluminum?

A washer can help distribute bearing pressure, but aluminum alloy, thickness, clamp load, hole geometry and galvanic compatibility should also be evaluated.

Should I use a washer on plastic?

Potentially.

A larger bearing area can reduce local pressure, but creep and stress relaxation must still be considered.

Do spring washers prevent bolts from loosening?

They should not be treated as a universal solution for vibration-induced self-loosening.

Performance depends on the complete joint.

Can a flat washer stop vibration?

No.

A conventional flat washer should not be treated as a vibration damper.

Can a flat washer make a joint waterproof?

No.

Use a dedicated sealing system where sealing is required.

Should the washer go under the bolt head or nut?

It can be used under either or both, depending on which bearing interface requires control and what the drawing specifies.

Can I remove a washer from an existing assembly?

Do not change a controlled or validated assembly without engineering review.

Removing a washer can alter bearing pressure, geometry, friction and tightening behavior.

From “Does This Bolt Need a Washer?” to an Approved Fastening Specification

The search may begin with:

“Do I need a washer with this bolt?”

The engineering process should continue:

What Function Is Required?

Then:

What Is the Parent Material?

What Is the Hole Geometry?

What Bearing Area Is Required?

What Clamp Load Is Expected?

Is Locking Required?

Is Sealing or Electrical Isolation Required?

What Standard Controls the Joint?

Only then should the decision become:

No Washer / Flat Washer / Hardened Washer / Spring Washer / Disc Spring / Locking Washer / Sealing Washer / Specialty Washer

Procurement can then move from:

“Need washers.”

to:

Controlled Washer Specification → Qualified Supplier → Sample / Validation → Production RFQ

Industrial Washer and Fastener Solutions from JUXIN FASTENERS

JUXIN FASTENERS supports OEM sourcing of flat washers, hardened washers, spring washers, disc spring washers, bolts, screws, nuts,

 locking fasteners and custom fastening components for automotive equipment, EV systems, AI data centers, power electronics, 

electrical equipment, telecommunications, HVAC, industrial automation, machinery and heavy equipment.

For a broader overview of washer families, see Industrial Washers: Types, Functions & Selection Guide.

For flat-washer geometry and bearing-interface selection, see Washers and Bolts: Fastening Systems Selection Guide.

For high-strength fastener systems, see High-Strength Bolts & Nuts: Engineering Selection Guide.

For prevailing-torque anti-loosening alternatives, see Nylon Insert Locknuts for Anti-Vibration Applications.

For washer, bolt, nut or custom fastening RFQs, send your drawing, applicable standard, fastener size, washer function, dimensions, hardness, material, finish, 

parent material, joint application, quantity and estimated annual demand to:

info@juxinfasteners.com

The best engineering question is not:

“Does this bolt normally use a washer?”

It is:

“What function does this joint require—and is a washer the correct component to provide it?”