Characteristics and advantages
Self-lubricating bronze bearings
Self-lubricating bronze bearings are a type of bearing designed to operate without the need for external lubrication. They are particularly useful in applications where regular maintenance is difficult or impossible. These bearings are manufactured by incorporating solid lubricant materials, such as graphite, directly into the bronze matrix. Maintenance-free and does not require manual lubrication. Ideal for heavy loads, low speeds, and applications where adding oil or grease is challenging. Our pins and ejectors ensure durability, accuracy, and smooth performance in demanding applications. Whether you need hardened core pins, ejector pins, or precision sleeves, our components provide reliable performance where it counts. Discover our complete range.
Cost-Effective Type of bronze Bearing， Self-lubricating components
Cost-effective bronze bearings offer lower maintenance costs and extended service life, making them ideal for applications where manual lubrication is challenging or oil and grease cannot be used. They provide excellent lubrication under high loads and low speeds. Made from bronze or high-tensile brass, these self-lubricating bearings are custom-machined to client designs. Our components feature embedded graphite plugs for continuous lubrication, removing the need for external grease or oil. This results in lower maintenance, reduced downtime, and enhanced durability for your equipment. Efficiency begins with the right components—trust viiplus to ensure smooth operation.
Self-lubricating components use embedded graphite plugs for continuous lubrication during operation, eliminating the need for regular maintenance and external lubrication, thereby reducing downtime and enhancing performance.
High Load Capacity:
Bronze bearings can handle high loads and provide good shock absorption.
Corrosion Resistance
Bronze has inherent corrosion resistance, making these bearings suitable for various environments.
Marine
Suitable for shipboard equipment exposed to harsh, corrosive environments.
Construction
Used in heavy equipment and machinery that operates under high loads and dirty conditions.
Our complete product range， Plain Bearing Industries, maintenance-free
Our slide bearings at a glance.
Our bronze-based products are engineered to withstand the harsh conditions of oil and gas exploration and extraction. They provide exceptional resistance to corrosion and heat, along with excellent machinability and weldability. Explore our extensive catalog to find the ideal bearing for your project.
Our self-lubricating components use graphite as a lubricant, eliminating grease or oil contamination. Graphite, in its pure carbon form, both lubricates and sequesters effectively.
These components have a long service life, requiring few replacements. Primarily made of bronze, they are fully recyclable at end-of-life. The graphite remains safely sequestered for centuries.
Additionally, our components reduce friction, allowing machines to operate with less energy.
Bushings for Industrial Machinery
We supply high-performance industrial bushings engineered to meet the toughest operating conditions across a wide range of machinery.
Industrial bushings are essential components that help:
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Reduce friction and surface wear
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Absorb shock and dampen vibration
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Maintain accurate shaft and housing alignment
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Extend equipment service life
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Lower energy usage and minimize maintenance costs
Selecting the right bushing—whether self-lubricating, bronze, bi-metal, composite, or a custom-engineered solution—directly affects the reliability, efficiency, and long-term performance of your equipment.
With decades of industry expertise, we deliver application-specific bushing solutions that ensure smoother, quieter, and longer-lasting operation, even under extreme temperatures, high loads, and harsh working environments.
Contact us today for expert support in choosing the optimal bushing for your machinery.
Marine, and Heavy-Duty Equipment: Our products are designed to meet the rigorous demands of the defense, commercial marine, and heavy-duty equipment industries. They offer excellent resistance to corrosion, heat, and high-strength metals, making them suitable for challenging environments encountered by remote-operated vehicles, aircraft carriers, and submarines.
Commercial Marine (Merchant Ships / Maritime Sector)
Large Merchant Vessels / Container Ships
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Rudder stock & rudder blade connection bushings
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Windlass and winch chain wheel shaft bushings
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Cargo crane boom hinge points and hydraulic cylinder eyes
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Bow thruster drive-shaft bushings
Offshore Support Vessels (OSV / AHTS)
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Towing winch main-shaft bushings
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Shark jaw and towing post (bollard) pin bushings
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Active heave compensation (AHC) system sheave blocks
FPSO / Drilling Platforms
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Turret mooring system large-diameter slewing bushings
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Riser tensioner linkage bushings
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ROV (remotely operated vehicle) manipulator arm joints
Heavy-Duty Equipment (Construction & Mining Machinery)
Mining Dump Trucks (400-ton class)
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Front suspension spherical plain bushings
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Rear axle oscillation arm bushings
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Dump-body hoist cylinder eye bushings
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Steering cylinder pin bushings
Large Hydraulic Excavators (≥100 tons)
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Boom, stick, and bucket pivot points (20+ critical bushings)
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Lower swing bearing slider/bushing (for certain models)
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Travel motor gearbox output-shaft bushings
Port Reach Stackers / Container Handlers
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Spreader rotation motor output bushings
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Telescopic boom slider bushings (often composite self-lubricating types)
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Hoisting drum support bushings
Heavy Bulldozers / Wheel Loaders
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Blade lift and tilt cylinder pivot bushings
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Articulated frame steering joint bushings
Common Operating Challenges Across These Applications
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Constant exposure to seawater, salt-spray corrosion, extreme temperatures, vibration, heavy loads, and shock impacts
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Very limited maintenance windows (especially for naval and deep-sea vessels)
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Extremely high reliability requirements, often demanding 10+ years of maintenance-free or minimal-lubrication service
Tool and Die Industry: In the tool and die sector, aluminum bronze alloys are preferred for sliding parts such as bearings. These alloys provide the necessary strength and durability for stamping dies and other tooling applications.
Bushing Application in the Tool and Die Industry – Specific Locations and SolutionsIn the tool and die industry (especially high-volume stamping, fine blanking, progressive dies, transfer dies, and plastic injection molds), aluminum bronze bushings (typically C95400, C95900 grades) are the material of choice for critical sliding and wear-prone areas due to their excellent combination of:
- High mechanical strength (up to 120 ksi / 830 MPa)
- Outstanding wear resistance under high pressure and low-speed sliding
- Superior galling resistance against hardened tool steels (D2, M2, A2, etc.)
- Good corrosion resistance (important when using cutting fluids or coolant)
- Ability to embed hard particles without seizing
Key Specific Application Locations in Tool & Die
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Location in Die/Mold
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Typical Function of Bushing
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Why Aluminum Bronze is Preferred
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Common Alloy & Form
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Typical Alternatives (when Al-Bronze is overkill)
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Die guide posts / leader pins
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Precision guiding of stripper plate, punch plate, or upper/lower die halves
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Extremely high side loads, no lubrication or minimal lube → needs galling resistance
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C95400 or AMPCO 18 solid or drilled bushings
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Steel + DLC coating, bronze-graphite plugs
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Heel plates / wear heels
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Absorb lateral forces on cutting punches during blanking/piercing
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Very high pressure (up to 200 ksi contact stress), abrasive metal chips
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AMPCO 21 or 25 solid heels or inserted blocks
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Hardened tool steel + nitride, cast iron
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Stripper plate guide bushings
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Guide stripper plate on punch holder
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Repeated sliding + impact, often dry or semi-dry
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C95400 with internal grease grooves
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Self-lubricating bronze + graphite
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Center pillars / dowel pins
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Precise alignment of large progressive dies
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High shear + compressive loads
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C95900 hardened aluminum bronze
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Case-hardened steel
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Cam slides / aerial & die-mount cams
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Linear or angled movement of forming or piercing cams
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High contact pressure + sliding velocity up to ~0.5 m/s
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AMPCO 21 or M4 (copper-beryllium for extreme loads)
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Bronze with MoS₂ inserts, hardened steel + PVD
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Pad or pressure plate guides
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Guiding nitrogen cylinders or spring-loaded pressure pads
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Continuous sliding under high load, heat generation
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C95400 long-life bushings
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Ball cages (but more expensive)
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Pilot locating bushings
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Register strip or pre-punched holes for accurate progression
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Sliding + occasional seizing risk when misfed
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Aluminum bronze with straight or spiral grooves
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Hardened steel
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Injection mold leader pin bushings
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Guide core/cavity alignment in plastic molds
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High-temperature sliding (up to 300–400 °F), corrosive plastic outgassing
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C95400 or nickel-aluminum bronze (higher temp)
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Self-lube bronze, hardened steel + DLC
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Gibbing / gib ways
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Precision flat guiding (often in large dies)
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Extremely high surface pressure, flat-on-flat sliding
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gibs
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Flame-hardened steel ways
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Practical Solutions & Design Recommendations
- Self-Lubricating Variants
- Drill spiral or annular grease grooves + use high-temperature molybdenum grease.
- Embed solid lubricant plugs (graphite or MoS₂) → reduces maintenance in high-volume presses.
- Hardness Matching
- Aluminum bronze: 180–300 HB (depending on heat treatment).
- Mate against hardened tool steel ≥58 HRC → optimal hardness difference prevents galling.
- Surface Finish
- Superfinish bushings to Ra 0.1–0.2 μm → dramatically increases life in dry or semi-dry conditions.
- Press-Fit vs. Replaceable
- Small dies: press-fit solid aluminum bronze bushings.
- Large/high-value dies: use demountable bushings with aluminum bronze liners.
- Extreme Cases
- When loads exceed aluminum bronze limits → switch to or tungsten carbide inserts, but cost ×5–10.
Real-World Performance ExampleA major automotive tier-1 stamper replaced traditional phosphor bronze + graphite plug bushings with C95400 aluminum bronze on 1000-ton progressive dies → bushing life increased from 400,000 to 2.8 million hits with zero seizures, even under minimal lubrication.Summary: In the tool and die industry, aluminum bronze bushings are the gold standard wherever high-pressure, low-speed sliding occurs against hardened tool steels — especially guide posts, heels, cams, and gibbing. They provide the best balance of wear life, galling resistance, and cost for long-running stamping and injection molding tools.
Plastic Mold Tooling: We supply high-strength, high-hardness, and high-conductivity products essential for tooling applications. Copper-based alloys are vital in the mold industry due to their corrosion resistance, ease of weldability, and high conductivity, making them ideal for injection molding, thermal forming, injection blow molding, and die casting projects.
Applications and Solutions of Metal-Backed Self-Lubricating Bushings in Plastic Injection Molds
(Metal-Backed PTFE/POM Composite Plain Bearings)
Metal-backed composite bushings—typically constructed with steel backing + sintered bronze layer + PTFE or POM self-lubricating overlay—are the preferred high-performance guide bushings for plastic injection molds. They are widely used in the following key areas:
1. Linear Guidance Between Moving and Fixed Mold Halves (Most Common Application)
Typical Locations:
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Leader pin & leader bushing
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Ejector sleeve
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Angle pin
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Slider & wear plate contact surfaces
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Wear plates under slide blocks
Why Metal-Backed Self-Lubricating Bushings?
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High mold cycle counts (500,000–2,000,000+ cycles) easily cause premature wear, scoring, and seizure in conventional phosphor bronze bushings with graphite plugs.
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The PTFE/POM self-lubricating layer forms a transfer film under dry or micro-lubricated conditions.
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Friction coefficient as low as 0.03–0.10, dramatically reducing wear.
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Steel backing + porous bronze layer provides high load capacity (>250 MPa), outperforming all-plastic bushings and ensuring reliability under high surface pressure.
2. Ejector System
Typical Locations:
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Ejector pin bushings
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Ejector sleeve guide bushings
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Return pin guiding
Advantages:
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Prevents seizure during high-speed, high-frequency ejection, avoiding powder contamination in the cavity.
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Heat-resistant up to 280°C (short-term 310°C)—ideal for high-temperature engineering plastics such as PA66+GF, PBT, LCP, PPS.
3. Core/Cavity Sliders – Large Sliding Wear Areas
Typical Locations:
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Slider bottom wear plates
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Contact surfaces between angle pin and slider
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Heel block contact areas
Recommended Configurations:
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Steel-backed bronze + PTFE wear plates (1.5–3 mm thickness)
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Custom-machined L-shaped or T-shaped wear blocks
4. Hot Runner Systems (High-Temperature Miniature Guidance)
Small PTFE/POM bushings (OD 6–20 mm) can be used for guiding:
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Hot runner nozzles
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Valve pins
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Locating pins and other precision guidance points
Comparison of Copper-Based Alloys Commonly Used in Injection Molds
| Material Type | Typical Mold Locations | Key Advantages | Limitations | Recommended Use |
|---|---|---|---|---|
| High-strength brass (ZCuZn25Al6Fe3Mn3) | Cooling plugs, locator seats, inserts | High strength, wear-resistant, cost-effective | Average thermal conductivity, no self-lubrication | Low-to-medium speed, high-load non-guiding areas |
| Beryllium copper (C17200/C17300) | Core/cavity cooling inserts, hot nozzle pins | Extremely high thermal conductivity (>300 W/m·K), corrosion-resistant | Expensive; toxic dust during machining | Thin-wall and high-gloss parts requiring rapid heat dissipation |
| Aluminum bronze (CuAl10Fe5Ni5) | Large inserts, sliders | High hardness, seawater corrosion resistance | Lower thermal conductivity compared to BeCu | Blow-molding molds, high-wear structural areas |
| Metal-backed self-lubricating bushings (PTFE/POM) | All moving guidance and ejection areas | Self-lubricating, long service life, maintenance-free | Higher cost vs. standard bronze | High-precision, high-speed, long-life molds (preferred) |
Recommended Solutions Based on Mold Life Requirements
| Mold Life Requirement | Recommended Guiding System |
|---|---|
| < 300,000 shots | Standard high-strength brass bushings + regular lubrication |
| 300,000–1,000,000 shots | Brass bushings with graphite plugs or POM metal-backed bushings (POM lubricated layer) |
| 1,000,000–3,000,000+ shots | PTFE metal-backed bushings (PTFE dry-lubrication layer) or SF-1D hydraulic-grade bushings + forced lubrication |
| Ultra-long life / oil-free mold design | Full set of PTFE/POM metal-backed self-lubricating bushings + steel-backed PTFE wear plates + DLC-coated leader pins |
Conclusion (One-Sentence Recommendation)
In modern high-precision, high-speed, long-life injection molds, metal-backed self-lubricating bushings (SF-1 series) have largely replaced traditional phosphor bronze bushings and are now the standard choice for leader pins, ejector systems, and slider wear surfaces. Copper-based alloys (brass, beryllium copper, aluminum bronze) remain ideal for static or semi-static components requiring high strength and high thermal conductivity, such as cooling inserts and core blocks.
Food and Beverage Industry: Operating under stringent cleanliness and sanitation requirements, the food and beverage industry demands components that prevent contamination. Our bushings and bearings are designed to meet these strict standards, ensuring safety and suitability in food production environments.
For detailed product information and to identify the most suitable bearing for your project, please refer to our extensive catalog or contact us directly.
Typical Applications and Solutions for Metal-Backed Self-Lubricating Bushings in the Food & Beverage Industry
(Metal-Backed PTFE / Polymer Composite Plain Bearings)
In the food and beverage industry, machinery components must comply with strict hygiene standards. Equipment must also withstand frequent high-pressure washdowns, chemical cleaning agents, steam sterilization, and corrosion from acidic or alkaline food media.
Metal-backed self-lubricating bushings—typically constructed with a steel or stainless-steel backing + bronze/sintered layer + PTFE or food-grade polymer coating—are engineered specifically for these demanding conditions.
Below is a summary of the most common application areas, their operating conditions, and recommended bushing solutions in food & beverage processing machinery.
1. Filling Machines – Filling Valves & Rotary Distributors
Operating Conditions:
High-speed rotation/reciprocation, frequent washdown, acidic beverages.
Recommended Solution:
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Steel backing + PTFE (or POM alternative)
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Food-grade PTFE composite bushings
Key Advantages:
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FDA-compliant
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Self-lubricating, grease-free
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Prevents contamination
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Resistant to >100°C cleaning chemicals
2. Aseptic Filling Valves – Ultra-Clean Guiding Components
Operating Conditions:
Sterile environment, steam sterilization at 135°C+, dry running.
Recommended Solution:
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Stainless-steel backing + PEEK/PTFE composite
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Full PEEK bushings
Key Advantages:
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Withstands >200°C steam
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No particle shedding
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Extremely low friction
3. Labeling Machines – Glue Rollers & Pressure Rollers
Operating Conditions:
Adhesive exposure, frequent washdown, aggressive cleaning agents.
Recommended Solution:
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Steel backing + food-grade POM coating
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Modified PTFE food-grade bushings
Key Advantages:
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Wear-resistant
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Chemical-resistant
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Non-stick (anti-glue adhesion)
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Long service life
4. Conveyor Flippers & Directional Guide Rails
Operating Conditions:
Heavy loads, alternating dry/wet environments, sugar/powder contamination.
Recommended Solution:
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Steel backing + high-load food-grade PTFE
Key Advantages:
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High load capacity (>250 MPa static)
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Wear life >100,000 cycles
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Oil-free, clean operation
5. Homogenizers & Mixer Shafts
Operating Conditions:
Medium-high speeds, fruit pulp/emulsions, CIP cleaning, acid/alkali corrosion.
Recommended Solution:
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Stainless-steel backing + PTFE bushes
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High-performance polymer composite bushings
Key Advantages:
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Excellent chemical resistance
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Suitable for direct food contact
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Resists emulsions and acidic media
6. Sterilizer Chains & Tray Guides
Operating Conditions:
High-temperature humidity (80–120°C), heavy-duty continuous operation.
Recommended Solution:
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Steel backing + high-temperature food-grade PTFE
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Solid-lubricant embedded bushings
Key Advantages:
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Steam-resistant
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No debris shedding
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Maintenance-free for >500,000 cycles
7. Pump Valves (Piston Pumps / Rotary Pumps)
Operating Conditions:
High-speed reciprocation, direct contact with food media, CIP/SIP cleaning.
Recommended Solution:
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316L stainless-steel backing
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PTFE composites Bushes
Key Advantages:
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Extremely low friction
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Wear-resistant
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Fully compliant with 3-A sanitary requirements
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Safe for direct food contact
8. Weighing & Sorting Equipment – Flippers, Lift Arms
Operating Conditions:
Light-load, high-speed motion, frequent starts/stops, ultra-clean environments.
Recommended Solution:
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Ultra-thin-wall food-grade self-lubricating bushings (0.5–1.0 mm wall)
Key Advantages:
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Space-saving design
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Grease-free, noise-free
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Ideal for sterile, high-precision equipment
9. Capping Heads & Capper Guides
Operating Conditions:
High-speed impacts, dry running, alcohol-based cleaning.
Recommended Solution:
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Steel backing + modified food-grade PTFE (low start-up friction)
Key Advantages:
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Start-up friction coefficient <0.05
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Handles high-frequency motion
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Wear resistant under dry-running conditions
Type of Self-lubricating Bushing Bearing
Variety of Self-lubricating Bushing Bearings Available
Leaded bronzes, also known as leaded tin bronzes, are prized for their outstanding corrosion resistance and operational qualities. Composed mainly of copper, tin, and lead, the inclusion of lead improves machinability and self-lubricating properties, making these alloys ideal for applications where lubrication is difficult or unfeasible.
