Aluminum
Lightweight Bearing Solutions
When weight matters. Aluminum alloys provide exceptional strength-to-weight ratio for aerospace, automotive, and high-performance bearing applications.
Aluminum in Bearing Applications
Aluminum is the third most abundant element in Earth's crust and the most widely used non-ferrous metal. In bearing applications, aluminum's exceptional strength-to-weight ratio and thermal conductivity make it valuable for specific applications where these properties are critical.
Pure aluminum is too soft for direct bearing surfaces. Instead, aluminum is used in bearings through three primary approaches: as bearing housings (pillow blocks, flanged units), as aluminum-tin bimetal bearings (engine bearings), and as a component in aluminum bronze alloys (copper-based alloys with aluminum addition).
JBM offers aluminum bronze bushings — high-strength copper alloys containing 9-14% aluminum that provide exceptional corrosion resistance and load capacity for marine and heavy-duty applications.
Why Aluminum for Bearings?
1/3 the weight of steel — critical for aerospace
4x better than steel — excellent heat dissipation
Natural oxide layer provides protection
Easy to machine, reduces manufacturing cost
Aluminum Properties
| Symbol | Al |
| Atomic Number | 13 |
| Density | 2.70 g/cm³ |
| Melting Point | 660°C (1220°F) |
| Thermal Conductivity | 205 W/m·K |
| Tensile Strength (6061-T6) | 310 MPa |
| Hardness (6061-T6) | HB 95 |
| Coefficient of Expansion | 23.1 µm/m·°C |
| Electrical Conductivity | 61% IACS |
Important Consideration
Pure aluminum is not suitable as a direct bearing surface against steel shafts — it's too soft and prone to galling. Use aluminum bronze, bimetal bearings, or lined aluminum housings instead.
How Aluminum is Used in Bearing Systems
Aluminum serves different roles in bearing systems depending on the application requirements. Here are the three primary ways aluminum contributes to bearing technology.
Bearing Housings
Aluminum is widely used for bearing housings — the structural component that holds the bearing in place. Pillow blocks, flanged units, and take-up frames are commonly made from cast or machined aluminum when weight reduction is important.
- 60-70% weight reduction vs. cast iron
- Excellent heat dissipation from bearing
- Corrosion resistant (anodized options)
- Cost-effective CNC machining
Aluminum Bronze Bushings
Aluminum bronze is a copper-based alloy containing 9-14% aluminum. Despite the name, it's primarily copper — the aluminum addition provides exceptional strength, corrosion resistance, and wear properties.
- Superior seawater/marine corrosion resistance
- High load capacity (120+ N/mm²)
- Excellent for high-temperature applications
- Self-lubricating with graphite plugs
Aluminum-Tin Bimetal Bearings
Engine bearings (crankshaft, connecting rod) use aluminum-tin alloys bonded to steel backing. The soft aluminum-tin surface conforms to the shaft and provides excellent embeddability for dirt particles.
- Excellent conformability to shafts
- High fatigue resistance
- Good embeddability for contaminants
- Superior thermal conductivity
Aluminum Alloys for Bearing Applications
Different aluminum alloys offer varying combinations of strength, corrosion resistance, and machinability. The right choice depends on your specific application requirements.
| Alloy | Type | Key Properties | Bearing Application |
|---|---|---|---|
| 6061-T6 | Al-Mg-Si | Good strength, excellent corrosion resistance, weldable | Bearing housings, mounting plates, structural frames |
| 7075-T6 | Al-Zn | Very high strength, aerospace grade, less corrosion resistant | High-performance housings, aerospace bearing mounts |
| 2024-T3 | Al-Cu | High strength, good fatigue resistance, lower corrosion | Aircraft bearing housings, high-stress applications |
| C95400 | Al-Bronze | High strength (700 MPa), excellent seawater resistance | Marine bushings, heavy-load bearings, valve guides |
| C95500 | Ni-Al-Bronze | Highest strength Al-bronze, superior corrosion resistance | Ship propellers, marine hardware, extreme environments |
| Al-Sn20 | Al-Tin | Soft, conformable, excellent embeddability | Engine crankshaft bearings, connecting rod bearings |
Highlighted rows are copper-based aluminum bronze alloys — technically bronze, not aluminum.
The Premier Marine Bearing Alloy
Aluminum bronze deserves special attention as the go-to material for marine, hydropower, and corrosive environment bearings. Despite containing "aluminum" in its name, it's a copper-based alloy.
Aluminum Bronze Composition
Typical C95400 / CuAl10Ni5Fe4 composition
Why Aluminum Bronze for Bearings?
- Seawater Resistance: Aluminum forms a protective oxide layer that resists saltwater corrosion far better than standard bronze.
- High Strength: Tensile strength up to 700 MPa — comparable to some steels while maintaining bronze's bearing properties.
- Non-Sparking: Safe for explosive environments (oil & gas, mining).
- Biofouling Resistance: Naturally resists marine growth on underwater surfaces.
- High Temperature: Maintains strength at elevated temperatures better than tin bronzes.
Aluminum vs. Other Housing & Bearing Materials
| Property | Aluminum (6061) | Cast Iron | Steel | Al-Bronze |
|---|---|---|---|---|
| Density | 2.7 g/cm³ | 7.2 g/cm³ | 7.8 g/cm³ | 7.5 g/cm³ |
| Weight (relative) | 1x (lightest) | 2.7x | 2.9x | 2.8x |
| Thermal Conductivity | 205 W/m·K | 50 W/m·K | 50 W/m·K | 60 W/m·K |
| Corrosion Resistance | Good | Poor | Poor | Excellent |
| Strength | Medium | Medium | Very High | High |
| Cost | Medium | Low | Low-Medium | High |
| Best For | Lightweight housings | Heavy-duty housings | High-load structures | Marine bearings |
Benefits of Aluminum in Bearing Systems
Lightweight
Only 1/3 the weight of steel. Critical for aerospace, robotics, portable equipment, and anywhere weight reduction improves performance.
Heat Dissipation
Thermal conductivity 4x higher than steel. Aluminum housings help cool bearings, extending lubricant and bearing life.
Corrosion Resistant
Natural aluminum oxide layer provides corrosion protection. Anodizing further enhances durability and appearance.
Easy Machining
Aluminum machines easily and quickly, reducing manufacturing costs for complex housing geometries.
Dimensional Stability
Maintains tight tolerances after heat treatment. Stress-relieved aluminum remains dimensionally stable.
Recyclable
100% recyclable with high scrap value. Recycling uses only 5% of the energy needed for primary production.
Aesthetic Appeal
Natural silver finish or anodized colors. Attractive appearance for visible applications and consumer products.
Non-Magnetic
Aluminum is non-magnetic — important for MRI equipment, electronics, and sensitive instrumentation.
Need aluminum bronze bushings or custom aluminum housings? Contact our engineering team.
Get a QuoteWhere Aluminum Bearing Solutions Excel
Aluminum and aluminum bronze serve different bearing niches — from weight-critical aerospace to corrosion-resistant marine applications.
Aerospace
- Actuator housings
- Control surface mounts
- Landing gear components
- Instrument enclosures
- Antenna gimbals
Marine & Offshore
- Rudder bearings (Al-Bronze)
- Propeller shaft bushings
- Deck equipment
- Underwater actuators
- Offshore platform hardware
Automotive
- Engine main bearings
- Connecting rod bearings
- Camshaft bushings
- Transmission housings
- EV motor mounts
Robotics & Automation
- Joint housings
- Actuator mounts
- End effector frames
- Sensor housings
- Linear guide supports
Food & Packaging
- Conveyor supports
- Packaging machinery
- Filling equipment
- Washdown environments
- Clean room equipment
Hydropower
- Wicket gate bushings (Al-Bronze)
- Guide vane bearings
- Turbine components
- Dam gate mechanisms
- Penstock supports
Working with Aluminum in Bearing Systems
⚠️ Galvanic Corrosion
Aluminum corrodes when in direct contact with dissimilar metals (especially copper, brass, steel) in the presence of moisture. Use isolation materials (bushings, coatings) or specify aluminum bronze instead.
⚠️ Thermal Expansion
Aluminum expands almost twice as much as steel when heated (23 vs. 12 µm/m·°C). Account for clearance changes in high-temperature applications.
✓ Surface Treatment
Hard anodizing increases surface hardness to HV 400+, improving wear resistance. Essential when aluminum contacts moving parts.
✓ Insert Bearings
For best results, use aluminum housings with pressed-in steel or bronze bearing inserts. This combines lightweight housing with proper bearing surfaces.
Need Aluminum or Aluminum Bronze Bearings?
JBM offers aluminum bronze bushings for marine and heavy-duty applications, plus custom aluminum housing solutions. Get the right material for your specific requirements.
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