Inside 360 Degree Rotation Chair Mechanism: Detailed Technical Information, Quality Standards, and Practical Uses

Types of 360 Degree Rotation Chair Mechanisms

A 360-degree rotation chair mechanism is a crucial engineering component that enables full-circle swiveling motion, enhancing accessibility, ergonomics, and user convenience. These mechanisms are widely used in office, medical, gaming, and home furniture. Understanding the different types helps in selecting the right chair for specific needs—whether it's comfort, durability, adjustability, or task-specific functionality.

Swivel Mechanism

The most fundamental type, allowing smooth 360° rotation without additional features.

Advantages

• Simple and reliable design
• Low maintenance
• Cost-effective manufacturing
• Smooth rotational movement

Limitations

• No height or tilt adjustment
• Limited ergonomic support
• May wear faster under heavy use

Best for: Office chairs, bar stools, casual seating

Ball Bearing Turntable

Utilizes precision ball bearings to minimize friction for ultra-smooth rotation.

Advantages

• Exceptionally smooth swivel action
• Reduced mechanical wear
• Longer lifespan with consistent performance
• Quiet operation

Limitations

• Higher manufacturing cost
• Requires occasional lubrication
• Sensitive to dust and debris if not sealed

Best for: Gaming chairs, executive seating, high-use environments

Gas Lift Mechanism

Combines 360° rotation with pneumatic height adjustment via a gas cylinder.

Advantages

• Adjustable seat height for ergonomics
• Easy one-lever operation
• Supports dynamic sitting postures
• Widely standardized and replaceable

Limitations

• Gas cylinder can degrade over time
• More complex than basic swivel
• Potential safety concerns if low-quality

Best for: Ergonomic office chairs, salon chairs, conference seating

Multi-Function Mechanism

Advanced system offering rotation plus tilt, height, seat depth, and armrest adjustments.

Advantages

• Highly customizable ergonomics
• Supports active sitting and posture changes
• Ideal for long-duration use
• Enhances comfort and productivity

Limitations

• Expensive to produce and repair
• Bulkier design
• Steeper learning curve for users

Best for: Executive chairs, premium gaming setups, therapeutic seating

Plateau Swivel Base

Heavy-duty swivel with a wide, flat base plate for maximum stability and load-bearing.

Advantages

• Extremely durable and stable
• Supports high weight capacities (up to 500+ lbs)
• Resists wobbling under stress
• Long service life in demanding settings

Limitations

• Bulkier and heavier design
• Less common in standard office furniture
• Higher cost due to robust materials

Best for: Recliners, accent chairs, medical reclining units

Locking Swivel Mechanism

Allows rotation with the ability to lock the chair in fixed positions for stability.

Advantages

• Provides stability when needed
• Ideal for precision tasks
• Reduces accidental movement
• Enhances safety in clinical settings

Limitations

• Mechanical complexity increases maintenance
• Locking mechanism may wear out
• Slightly more resistance during swivel

Best for: Task chairs, dental/medical exam chairs, control room seating

Friction Swivel

Relies on controlled friction between parts to allow rotation or fixed positioning.

Advantages

• No moving parts or bearings required
• Low cost and easy to manufacture
• Can be adjusted for tighter or looser rotation
• Durable in simple applications

Limitations

• Less smooth than bearing-based systems
• May loosen over time
• Not suitable for high-frequency use

Best for: Rocking chairs, gliders, nursery furniture

Heavy-Duty Swivel

Built for industrial and commercial use with reinforced materials and construction.

Advantages

• Extremely robust and long-lasting
• Resists wear from constant use
• High load tolerance
• Corrosion-resistant materials often used

Limitations

• Heavier and less portable
• Higher initial investment
• Limited availability in consumer markets

Best for: Industrial stools, construction site seating, factory workstations

Compact Swivel Mechanism

Space-saving design ideal for chairs with minimal internal clearance.

Advantages

• Minimal footprint
• Enables rotation in small furniture
• Lightweight and efficient
• Perfect for tight spaces

Limitations

• Lower weight capacity
• Limited adjustability options
• May not support prolonged heavy use

Best for: Small accent chairs, compact apartments, children’s furniture

Mechanism Type	Rotation Smoothness	Adjustability	Durability	Ideal Use Case
Swivel Mechanism	Good	None	Medium	Basic office/bar stools
Ball Bearing Turntable	Excellent	Rotation only	High	Gaming, executive chairs
Gas Lift Mechanism	Good	Height + Rotation	Medium-High	Ergonomic office seating
Multi-Function Mechanism	Very Good	Full (tilt, height, depth)	High	Premium executive/gaming
Plateau Swivel Base	Smooth	Rotation only	Very High	Recliners, medical chairs
Locking Swivel	Controlled	Rotation + Lock	High	Medical, task chairs
Friction Swivel	Fair	Fixed or loose rotation	Medium	Rockers, gliders
Heavy-Duty Swivel	Smooth (under load)	Rotation-focused	Exceptional	Industrial, construction
Compact Swivel	Fair to Good	Rotation only	Medium	Small spaces, accent furniture

Expert Tip: For optimal longevity, periodically inspect your chair’s swivel mechanism for signs of wear, especially if it uses ball bearings or a gas lift. Applying silicone-based lubricant (not oil) can help maintain smooth operation and prevent squeaking.

Functions and Features of 360-Degree Rotation Chair Mechanism

The 360-degree rotation chair mechanism is a pivotal innovation in modern seating design, especially in office, gaming, and ergonomic furniture. This mechanism enables a full circular swivel, allowing users to rotate smoothly around the vertical axis of the chair without needing to reposition the entire seat. This functionality enhances accessibility, improves workflow efficiency, and supports dynamic movement during work or leisure activities—such as reaching for documents, engaging in group discussions, or transitioning between multiple monitors.

Beyond basic rotation, today’s mechanisms integrate advanced engineering for comfort, safety, and durability. Below is a detailed breakdown of the core functions and key features that define high-performance 360-degree swivel systems.

Core Functions of the Rotation Mechanism

Effortless Mobility

The primary function of the 360-degree mechanism is to provide seamless rotational movement. This allows users to access different areas of their workspace—such as side desks, shelves, or colleagues—without standing up or sliding the chair across the floor. This reduces physical strain and increases productivity in environments requiring frequent directional changes.

Ergonomic Support

By enabling controlled rotation, the mechanism supports natural body movement, reducing the need for awkward twisting of the spine. This contributes to better posture and decreased risk of musculoskeletal issues over time, particularly in long-duration work settings like offices or control rooms.

Key Features and Engineering Components

Swivel Function: At the heart of the mechanism is a precision-engineered swivel joint that allows smooth, continuous 360-degree rotation. High-quality mechanisms use tight tolerances and polished surfaces to minimize resistance and ensure consistent performance over years of use.

Ball Bearing System: Most premium chairs utilize sealed ball bearing assemblies between the base and the stem. These bearings reduce friction, prevent wobbling, and allow for silent, fluid rotation even under heavy loads. The use of stainless steel or chrome-plated bearings also enhances corrosion resistance and longevity.

Stability and Weight Distribution: The mechanism is designed to evenly distribute the user’s weight across the chair base, typically a five-star configuration. Reinforced center hubs and thick metal spindles ensure structural integrity, with many models supporting up to 300 lbs (136 kg) or more. This stability prevents tipping and enhances user confidence during movement.

Height Adjustability (Gas Lift Integration): Many 360-degree mechanisms are paired with pneumatic gas lift cylinders, allowing users to adjust seat height effortlessly. This feature is crucial for aligning the chair with various desk heights and promoting proper ergonomics, including 90-degree knee angles and aligned eye levels with screens.

Rotation Locking Mechanism: Some advanced models include a lockable swivel option, which fixes the chair in one position when needed. This is particularly useful during meetings, presentations, or when getting in and out frequently, as it prevents unintended spinning and improves stability.

Easy Installation & Modular Design: Modern rotation mechanisms are often pre-assembled or come with standardized mounting patterns (e.g., 2” or 50mm diameter stems). This simplifies installation for manufacturers and facilitates replacement for end-users or repair technicians, reducing downtime and maintenance costs.

Versatile Compatibility: These mechanisms are engineered to fit a wide range of chair types, including executive office chairs, gaming seats, drafting chairs, and lounge furniture. Their universal design makes them a preferred choice for furniture manufacturers aiming for modularity and scalability across product lines.

Durability and Material Quality: Constructed from reinforced nylon, die-cast aluminum, or hardened steel, these mechanisms are built to endure daily use in both home and commercial environments. Surface treatments like chrome plating or powder coating protect against rust, scratches, and wear, ensuring long-term reliability.

Feature	Functionality	Common Applications
360° Swivel	Full rotational mobility around central axis	Office desks, conference rooms, control centers
Ball Bearings	Smooth, low-friction rotation with minimal noise	Premium office and gaming chairs
Gas Lift Compatibility	Height adjustment via pneumatic cylinder	Ergonomic office seating, adjustable workstations
Lockable Base	Fixed position mode for added stability	Meeting rooms, training centers, medical seating
Universal Mounting	Standardized stem size for broad compatibility	Furniture manufacturing, DIY chair builds

Important: Always verify weight capacity and compatibility before replacing or upgrading a chair mechanism. Using an undersized or incompatible mechanism can lead to instability, premature failure, or safety hazards. Regular cleaning and inspection of the swivel joint and bearings can extend the life of the mechanism and maintain smooth operation. For optimal performance, avoid exposing the base to excessive moisture or abrasive substances.

Scenarios of 360-Degree Rotation Chair Mechanism

The 360-degree rotation mechanism is a pivotal innovation in modern seating design, offering enhanced mobility, flexibility, and ergonomic support across various environments. This feature allows users to pivot smoothly in any direction without needing to stand or reposition the chair manually, improving accessibility and comfort. Its applications span multiple types of seating solutions, each tailored to specific user needs and functional demands.

Office Chairs

Office chairs are engineered to support prolonged sitting, providing lumbar support, adjustable height, and comfortable cushioning for daily work use. The integration of a 360-degree swivel mechanism enhances productivity by enabling employees to reach different workstations, shelves, computers, or colleagues without straining their bodies.

• Ideal for home offices, corporate environments, and co-working spaces
• Reduces physical strain during multitasking between monitor, keyboard, printer, and filing cabinets
• Often paired with casters for full mobility and tilt mechanisms for dynamic sitting

Key Benefit: Promotes healthy posture and minimizes repetitive motion injuries

Gaming Chairs

Designed for extended gaming sessions, gaming chairs combine aggressive styling with high comfort and performance features. The 360-degree rotation allows gamers to quickly shift focus between multiple screens, consoles, or teammates during live gameplay or streaming setups.

• Enables rapid reorientation during competitive gaming or live broadcasts
• Facilitates easy interaction with peripherals like microphones, lighting controls, or secondary monitors
• Enhances immersion and responsiveness in fast-paced games requiring situational awareness

Pro Tip: Look for reinforced bases and smooth-glide mechanisms to ensure durability under frequent spinning

Ergonomic Chairs

Ergonomic chairs are scientifically designed to align the spine, reduce pressure points, and support natural body movement. The 360-degree swivel complements other ergonomic features such as adjustable armrests, seat depth, and back angle, allowing seamless transitions between tasks.

• Supports dynamic sitting by encouraging micro-movements throughout the day
• Helps prevent lower back pain and hip stiffness during long work hours
• Improves reachability to collaborative tools and reduces neck strain from twisting

Critical Insight: Swivel functionality is essential in modern ergonomic design to promote active sitting

Recliners

Modern recliners with 360-degree rotation offer both relaxation and spatial flexibility. These chairs provide full back, neck, and leg support while allowing users to pivot effortlessly to view TVs, guests, or outdoor views without getting up.

• Perfect for living rooms, media centers, or senior-friendly spaces
• Lumbar and neck support help alleviate chronic back discomfort
• Rotating base enhances independence for elderly or mobility-limited individuals

Smart Feature: Motorized rotating recliners combine swivel with power recline for ultimate convenience

Task Chairs

Task chairs are specialized for precision work in laboratories, drafting studios, workshops, and medical facilities. The 360-degree rotation allows professionals to maintain optimal positioning while switching between tools, instruments, or workbenches.

• Height-adjustable designs paired with swivel enhance precision and control
• Used in dental clinics, engineering labs, and electronics assembly stations
• Durable materials resist wear from frequent rotation and chemical exposure

Functional Advantage: Increases efficiency by minimizing unnecessary standing and repositioning

Dining Chairs

While less common, rotating dining chairs are gaining popularity in modern kitchens and social dining areas. They allow guests to easily engage in conversations around the table or turn toward entertainment centers without leaving their seats.

• Ideal for open-concept homes, breakfast nooks, or kitchen islands
• Encourages inclusive conversation flow during meals or gatherings
• Typically lack extensive back support due to short-duration use

Design Note: Often styled with minimalist aesthetics and cushioned seats for visual appeal and comfort

Professional Recommendation: When selecting a 360-degree rotating chair, prioritize build quality—especially the base (preferably five-star) and gas lift mechanism. Ensure smooth ball-bearing swivel systems for long-term durability. For commercial or high-use settings, opt for models with reinforced joints and weight capacity ratings that exceed expected usage.

Chair Type	Primary Use Case	Key Features	Rotation Benefit
Office Chair	Corporate & remote work	Adjustable height, lumbar support, casters	Efficient workstation access
Gaming Chair	Extended gaming/streaming	High backrest, RGB lighting, memory foam	Quick directional changes
Ergonomic Chair	Health-focused workspaces	Dynamic posture support, breathable mesh	Reduces musculoskeletal strain
Recliner	Home relaxation	Power recline, lumbar cushion, plush fabric	Full-room visibility without effort
Task Chair	Technical & medical tasks	Compact design, chemical-resistant materials	Precise tool access
Dining Chair	Social dining areas	Stylish finish, padded seat, compact size	Improved social engagement

Additional Considerations

• Mechanical Durability: High-quality swivel bases use reinforced nylon or aluminum with sealed bearings for smooth, quiet rotation
• Floor Protection: Chair glides or floor mats prevent scratches on hardwood or tile from constant spinning
• Weight Capacity: Industrial-grade models support up to 300+ lbs for heavy-duty applications
• Noise Level: Premium mechanisms operate silently, ideal for libraries, studios, or quiet offices
• Aesthetic Integration: Available in modern, minimalist, or luxury finishes to match interior decor

How to Choose the Right 360-Degree Rotation Chair Mechanism

Selecting the appropriate 360-degree swivel chair mechanism is essential for comfort, durability, and long-term performance—whether you're furnishing an office, gaming setup, or home workspace. A high-quality chair mechanism not only enables smooth rotation but also supports ergonomic adjustments that enhance posture and productivity. This comprehensive guide outlines the critical factors to consider when choosing a chair base mechanism, helping you make an informed decision based on your needs, budget, and usage.

Important Note: The chair mechanism (also known as the gas lift or center column) is the core component connecting the seat to the base and enabling height adjustment, tilt, and 360° rotation. Choosing the wrong mechanism can lead to premature failure, instability, or discomfort.

Key Factors to Consider When Choosing a 360° Chair Mechanism

1. Load Capacity (Weight Rating)

   Every chair mechanism is rated for a specific maximum weight capacity. Exceeding this limit can damage the gas lift, cause sudden descent, or compromise structural integrity.

   • Standard mechanisms typically support 250–300 lbs (113–136 kg)
   • Heavy-duty mechanisms are available for 400+ lbs (181+ kg), ideal for executive or industrial use
   • Always select a mechanism with a higher capacity than the expected user weight for safety and longevity
   • Higher load capacity mechanisms often use reinforced steel and dual-chamber gas springs
2. Material and Durability

   The materials used directly impact the mechanism’s lifespan, stability, and resistance to wear.

   • Metal components (especially steel or aluminum alloys) provide superior strength and longevity
   • Plastic or composite parts may reduce cost but can degrade over time under heavy use
   • Look for mechanisms with chrome-plated or powder-coated finishes to resist corrosion and scratches
   • High-quality ball bearings ensure smooth 360° rotation without wobbling or grinding
   • Gas lifts should be SGS, BIFMA, or ANSI certified for safety and performance standards
3. Design and Adjustability Features

   The mechanism determines the range of ergonomic adjustments available on the chair.

   • Height adjustment: Most mechanisms use pneumatic gas lifts for quick seat elevation
   • Tilt tension control: Allows users to adjust the resistance when reclining
   • Synchronous tilt: Enables coordinated movement of seat and backrest for balanced posture
   • Lockable tilt: Useful for tasks requiring a fixed upright position
   • Advanced mechanisms may include seat slide adjustment or lumbar support integration
4. Compatibility with Chair Components

   Ensure the mechanism fits seamlessly with your chair’s design and other parts.

   • Verify the mounting plate size and bolt pattern matches your seat base (common sizes: 7", 11", or custom)
   • Confirm compatibility with the five-star base (typically 1.25" or 1.5" diameter stem)
   • Check if the mechanism supports armrests, backrest angle adjustment, or seat sliders
   • For custom or DIY chairs, measure all dimensions precisely before purchasing
5. Ease of Installation and Assembly

   A user-friendly mechanism reduces setup time and avoids the need for professional help.

   • Look for mechanisms with clear installation guides and standard tools (e.g., Allen wrench)
   • Modular designs with pre-assembled tilt controls simplify setup
   • Gas lift insertion should be straightforward—often secured with a snap ring or pin
   • Some mechanisms require torque-specific tightening; a torque wrench may be needed for optimal safety
6. Maintenance Requirements

   Regular upkeep ensures smooth operation and extends the chair’s lifespan.

   • Most mechanisms require only occasional dusting and inspection for loose screws
   • Lubricate moving parts (e.g., tilt pivot points) annually with silicone-based lubricant
   • Avoid using oil-based lubricants that can degrade plastic components
   • Replace worn-out gas lifts promptly—signs include sinking seats or difficulty adjusting height
   • Commercial environments may require quarterly maintenance checks
7. Price and Long-Term Value

   While budget is important, prioritize value over initial cost.

   • Basic mechanisms start around $20–$40; premium models range from $60–$120+
   • Higher-priced mechanisms often include better warranties (e.g., 3–5 years)
   • Investing in a durable mechanism reduces long-term replacement costs
   • Consider total cost of ownership: cheaper parts may fail within 1–2 years, increasing waste and expense
   • Look for brands with proven reliability and accessible replacement parts

Feature	Budget Option	Mid-Range Option	Premium Option
Load Capacity	Up to 250 lbs	300–350 lbs	400+ lbs
Material Quality	Plastic gears, thin steel	Reinforced plastic + alloy steel	Full metal construction, chrome finish
Adjustability	Height only	Height + tilt tension	Height, tilt, lock, seat slide
Installation	Moderate (may need help)	Easy (DIY-friendly)	Tool-assisted but intuitive
Maintenance	High (annual check-ups)	Moderate (bi-annual)	Low (minimal upkeep)
Warranty	6–12 months	2–3 years	5+ years

Expert Tip: When replacing a gas lift or mechanism, always match the diameter of the stem (usually 1.25") and the overall height when compressed and extended. Mismatched dimensions can prevent proper installation or affect chair stability.

Final Recommendations

• For home offices: Choose a mid-range mechanism with height and tilt adjustment for comfort and durability
• For gaming or executive chairs: Opt for premium mechanisms with high weight capacity and smooth recline control
• For commercial or industrial use: Select heavy-duty, certified mechanisms with extended warranties
• Always test the swivel and height adjustment before final assembly
• Keep spare parts like snap rings or gas lifts on hand for quick repairs

Choosing the right 360-degree chair mechanism is a crucial step in building or upgrading a functional, comfortable, and safe seating solution. By evaluating load capacity, materials, adjustability, compatibility, and long-term value, you can ensure optimal performance and user satisfaction. Remember, the mechanism is the foundation of your chair—invest wisely to support both comfort and productivity over time.

360-Degree Rotation Chair Mechanism: Frequently Asked Questions

Q1: Can the chair mechanism be installed on any type of chair?

While a 360-degree rotation mechanism can technically be installed on many types of chairs, compatibility is crucial for both safety and functionality. The chair must have a central base or mounting plate that aligns with the stem or column of the swivel mechanism.

• Compatible Chairs: Office chairs, gaming chairs, bar stools, and some dining chairs are typically designed with standard 5/8" or 7/8" diameter mounting holes that fit most swivel bases.
• Structural Integrity: The chair frame must be strong enough to handle the dynamic forces of rotation and daily use without loosening or cracking.
• Mounting Hardware: Proper bolts, washers, and threading are essential to secure the mechanism. Mismatched hardware can lead to instability or damage.
• DIY Considerations: Retrofitting a non-swivel chair requires drilling and reinforcement. It’s recommended only for experienced users or with professional guidance.

For optimal performance and longevity, always choose a chair that is originally designed or explicitly labeled as compatible with a 360-degree swivel mechanism.

Q2: Is a reclining mechanism the same as a rotating mechanism?

No, a reclining mechanism and a rotating (swivel) mechanism serve entirely different functions and operate independently, though they are often combined in ergonomic seating solutions.

Feature	Reclining Mechanism	Rotating Mechanism
Primary Function	Allows the backrest to tilt backward at adjustable angles for comfort and relaxation.	Enables the entire seat to turn 360 degrees horizontally for mobility and reach.
Common Components	Tilt tension control, recline lock, spring or hydraulic system.	Swivel stem, bearing plate, base hub.
Typical Use Cases	Executive chairs, lounge chairs, gaming chairs with back support.	Office chairs, task chairs, stools, and workbenches.
User Interaction	Adjusts posture and reduces spinal strain during prolonged sitting.	Enhances accessibility to surrounding areas without standing.

Many high-end office chairs integrate both mechanisms, offering full ergonomic flexibility. However, each system must be properly engineered to avoid mechanical interference and ensure long-term reliability.

Q3: What is the weight limit for chairs with this type of mechanism?

The weight capacity of a chair with a 360-degree rotation mechanism varies significantly based on design, materials, and manufacturer specifications. It's essential to match the chair’s rating with the user’s weight to prevent premature wear or failure.

• Standard Office Chairs: Typically support 200–250 lbs (90–113 kg), suitable for most general-use environments.
• Heavy-Duty Models: Engineered for industrial or commercial use, these can handle 300–400 lbs (136–181 kg) or more, often featuring reinforced steel bases and dual-wheel casters.
• Bariatric Chairs: Specifically designed for higher weight capacities (up to 500+ lbs), with wider seats, thicker frames, and upgraded gas lifts.
• Gas Lift Rating: The pneumatic cylinder is a critical component—look for Class 3 or Class 4 gas lifts (ISO 11611 certified) for heavier loads and longer life.

Always check the manufacturer’s label or product manual for exact weight limits. Exceeding these can void warranties and compromise safety.

Q4: How does the gas lift mechanism work?

The gas lift, also known as a gas spring or pneumatic cylinder, is a key component in height-adjustable chairs that enables smooth and effortless seat elevation.

It operates using compressed nitrogen gas sealed within a cylinder. Here’s how it works:

1. Internal Pressure: The cylinder contains a piston connected to a rod that extends into the chair seat. High-pressure nitrogen is trapped in the lower chamber, creating upward force.
2. Control Valve: When the user pulls the height adjustment lever, a valve inside the cylinder opens slightly, allowing gas to move between chambers and releasing pressure.
3. Height Adjustment: As pressure is released, the user can raise or lower the seat. Releasing the lever closes the valve, locking the piston in place and maintaining the new height.
4. Smooth Operation: Unlike mechanical springs, gas lifts provide consistent resistance and quiet operation, making them ideal for frequent adjustments.

Gas lifts are durable and require no maintenance, but they can degrade over time—especially if overloaded or used in extreme temperatures. A failing gas lift may slowly sink or become difficult to adjust.

Q5: What materials are commonly used in the chair rotation mechanism?

The durability and performance of a 360-degree rotation mechanism depend heavily on the materials used in its construction. High-quality components ensure smooth movement, stability, and longevity.

• Swivel Stem & Hub: Typically made from hardened steel or aircraft-grade aluminum for strength and resistance to torsional stress. Steel offers superior durability, while aluminum reduces overall chair weight.
• Base (Star Base): Most commonly constructed from nylon-reinforced polypropylene (plastic) for lightweight use or die-cast aluminum/steel for heavy-duty models. Metal bases resist cracking under load and provide better balance.
• Bearings & Bushings: Precision ball bearings or PTFE (Teflon) bushings minimize friction, ensuring smooth 360-degree rotation. These are often enclosed to prevent dust and debris buildup.
• Mounting Plates & Fasteners: Steel plates with zinc or chrome plating prevent rust and corrosion. High-tensile bolts ensure a secure connection between the mechanism and the seat.
• Finish & Coating: Many mechanisms feature anti-corrosive coatings or powder finishes to enhance appearance and protect against wear in humid or high-use environments.

When selecting a chair, look for mechanisms labeled as “chrome-plated steel” or “reinforced aluminum” for maximum durability. Avoid chairs with entirely plastic internal components, as they may wear out quickly under regular use.