In industrial manufacturing, precision and reliability are essential. For engineers in North America and those working with American engineering standards, choosing the right material for oilless bearings often starts with ASTM specifications.

ASTM standards provide a reliable framework for chemical composition, mechanical properties, and material performance, helping ensure that self-lubricating bushings can withstand heavy loads, reduce friction, and deliver long service life.

Selecting a proven bronze base material is a key step in plain bearing and bushing design, especially for graphite-plugged oilless bushings.

This guide highlights two major ASTM standards widely used in the self-lubricating bearing industry:

• ASTM B505 — Continuous cast copper alloy shapes, commonly used for bearing bronzes such as C93200.
• ASTM B148 — Aluminum bronze sand castings, commonly used for high-strength grades such as C95400.

Please note that final bearing performance also depends on factors such as PV value, lubrication conditions, surface finish, shaft material, and correct installation. Material selection is only the first step toward reliable bearing performance.

Understanding ASTM B505 vs ASTM B148 (What the Standards Really Control)

ASTM B505 (Continuous Cast Copper Alloys)

ASTM B505/B505M is widely referenced for continuous-cast bronze bars, tubes, and plates used in bearings. In practice, engineers rely on B505 because it supports:

• Stable metallurgy and soundness for machined bushings
• Predictable machinability and dimensional stability
• Efficient production of bearing blanks

ASTM B148 (Aluminum-Bronze Castings)

ASTM B148 covers aluminum-bronze castings, and it’s commonly used when the application needs:

• Higher strength under heavy loads
• Better resistance to deformation and shock
• More demanding service environments than “general purpose” bearing bronze

Popular ASTM Alloys for Oilless Bearings

C86300 (Manganese Bronze) – The High-Strength Choice

For the most demanding “High-Load, Low-Speed” applications, ASTM C86300 Manganese Bronze is the industry standard.

• The “Heavy Lifter”: This alloy can support significantly higher loads than standard leaded bronzes. When combined with graphite solid lubricants, it eliminates the need for manual greasing in hard-to-reach areas like dam gates or mining shovels.

C93200 (SAE 660) — The “Default” Bearing Bronze

UNS C93200, also known as SAE 660, is one of the most common bronze materials for bushings and plain bearings because it balances:

• Good anti-friction behavior
• Excellent machinability
• Practical cost/performance for light to medium duty

Typical composition (reference range): Cu 81–85%, Sn 6.3–7.5%, Pb 6–8%, Zn 1–4% (plus minor elements).
This chemistry is a big reason why C93200 is so forgiving in real-world equipment: the alloy is designed for bearing service rather than “maximum strength at all costs.”

Where it wins in the market

• Replacement bushings for industrial equipment
• Hydraulic components and pump bushings
• General machinery where reliability and ease of machining matter

Where it is NOT the best answer

• Very high loads / shock loads where yield strength is the limiting factor
• Environments where lead restrictions apply

C95400 (Aluminum Bronze) — Heavy Load, High Strength

When engineers move from “general purpose bearing bronze” to “high load and punishment,” C95400 becomes a frequent shortlist material.

Why C95400 is different

• It is one of the highest-strength standard copper-based alloys in common industrial use.
• It performs well when a bushing must resist compressive stress and deformation.

Typical composition (per Copper.org):

• Cu: 83.0% min (with Cu + named elements total 99.5% min)
• Al: 10.0–11.5%
• Fe: 3.0–5.0%
• Ni (incl. Co): ≤1.5%
• Mn: ≤0.50%

Common reference standards include ASTM B148 and ASTM B505 (as well as other copper alloy standards), which makes C95400 easier to specify in global documentation.

Where it wins in the market

• Heavy machinery and construction equipment
• Agricultural equipment subject to shock loads
• Hydraulic cylinders, pivot points, and high-load bearing locations

Quick Selection Logic: C93200 vs C95400 (Engineering Shortcut)

Use the table below as a fast, practical screening tool before you run the detailed PV/load calculations.

Comparison Table (ASTM-focused)

Item	C93200 (SAE 660)	C95400 (Aluminum Bronze)
Typical use case	General-purpose bushings & bearings	High-load / shock-load bushings
Common ASTM pathway	ASTM B505 (continuous cast)	ASTM B148 (castings) + also referenced in other ASTM copper standards
What engineers usually search	“SAE 660 equivalent”, “C93200 bearing bronze”	“C95400 properties”, “aluminum bronze strength”
Strength bias	Moderate	High
Machinability bias	High	Moderate (depends on condition)
Typical industries	Pumps, general machinery, maintenance replacement	Heavy equipment, agricultural pivots, hydraulics

ASTM Bronze Material Comparison Table

ASTM Grade	Common Name	Tensile Strength (min)	Brinell Hardness	Best Use Case
C93200	SAE 660	35 ksi	70	General purpose, light-to-medium loads
C95400	Aluminum Bronze	75 ksi	170	Heavy loads, wear resistance, marine
C86300	Manganese Bronze	110 ksi	225	Ultra-high loads, low speed, heavy industry

Application Notes: Where ASTM-Specified Oilless Bushings Commonly Work

ASTM-based bronze selections are especially common in:

• Heavy machinery (pins, pivots, chassis joints)
• Agricultural equipment (high contamination, shock loading)
• Hydraulic systems (bushings, guides, wear rings)

For graphite-plugged designs (often called “oilless” or “self-lubricating” bushings), the bronze acts as:

• The structural load-bearing matrix
• The thermal conductor
  while the solid lubricant plugs provide boundary lubrication when grease/oil is absent.

Why Choose Bronzeoilless.com ASTM-Compliant Oilless Bearings?

At Bronzeoilless.com, we understand that “close enough” isn’t good enough for global trade. We strictly adhere to ASTM B505, B148, and B22 standards to ensure our international clients—from the USA to Canada and beyond—receive components that fit their technical drawings perfectly.

Whether you are designing for a sugar mill tandem or high-load port machinery, our ASTM-grade bronze oilless bearings provide the longevity and performance your project demands.