Premium Flanged Track Roller Bushings for Excavator Undercarriages

Engineered Cast Bronze Solutions for Heavy-Duty Equipment

Overview

The track roller bushing (also known as a bottom roller flanged bush) is a critical wear component in excavator undercarriage assemblies. Subject to intense heavy loads, constant shock, and harsh environments, this solid-cast flanged bushing demands uncompromising material integrity and dimensional precision.

We manufacture highly durable, centrifugally cast bronze track roller bushings tailored to your exact machine class, operating environment, and lubrication design.

Navigating the “CuSn8” Material Standard

European and international engineering drawings frequently specify “CuSn8” for track roller bushes. However, for thick-walled, heavy-duty applications, rolled strip alloys cannot be used.

When you specify CuSn8, we ensure you receive the correct Cast Tin Bronze (UNS C90300 / CuSn8Zn4)—not a mismatched substitute.

Our UNS C90300 Specifications:

• True Chemistry: Cu 86.0–89.0 | Sn 7.5–9.0 | Zn 3.0–5.0 (Lead-free).

• Mechanical Strength: Tensile strength ≥ 276 MPa, highly ductile to absorb undercarriage shock.

• Manufacturing Method: Centrifugally cast (or continuously cast) to eliminate the porosity and cored-dendrite microstructures common in sand casting, preventing crack initiation under impact.

• Global Standard Transparency: We quote exact ASTM B584 / B505 or EN material equivalents. We do not perform “blind substitutions” with local standards without customer engineering approval.

Selecting the Right Material for Your Operating Environment

While UNS C90300 (Cast CuSn8) is highly durable, it requires clean, reliable lubrication. Because excavator undercarriages face extreme contamination, we offer customized material solutions based on actual field duties:

1. Standard Heavy Duty (Well-Sealed Cavities)

• Material: Cast Tin Bronze UNS C90300 (CuSn8Zn4)

• Advantages: RoHS/REACH compliant (lead-free), excellent shock absorption, and high load-carrying capacity. Outstanding corrosion resistance for wet environments.

• Requirement: Operates optimally with properly sealed cavities, reliable grease paths, and mating pins hardened to 350–450 HB.

2. High-Contamination Environments (Mud, Sand, and Grit)

• Material: High-Leaded Tin Bronze (e.g., UNS C93700) or Graphite-Plugged Bronze.

• Advantages: Tin bronze (C90300) lacks embeddability. If mud or grit breaches the seals, a leaded or solid-lubricant-plugged bronze is highly recommended. These materials embed foreign particles, preventing them from scoring the roller shaft and extending the assembly’s lifespan.

3. Coastal, Marine, or Severe Demolition Duty

• Material: Nickel-Aluminum Bronze (UNS C95800).

• Advantages: Offers superior strength and ultimate resistance against seawater and brackish environments. Ideal for specialized dredging or marine construction excavators.

Why Source Your Undercarriage Bushings From Us?

• Application-Specific Engineering: We don’t just process orders; we review your application. We assess your sealing arrangement, lubrication regime, and ground conditions (rock vs. mud) to recommend the optimal alloy.

• Precision Machining: Flanged thrust faces and bore cylindricity are machined to precise tolerances to ensure perfect press-fit retention within the roller housing.

• Custom Lubrication Features: Available with customized grease pockets, grooves, or diamond patterns to ensure retained grease actively reaches the sliding surface.

• No Compromise on Casting Quality: We utilize centrifugal casting for all thick-walled flanged bushings, ensuring maximum metal density and structural integrity.

Ready to Optimize Your Undercarriage Components?
Contact our engineering team today to discuss your track roller bushing drawings, seal arrangements, and load requirements. We provide accurate quotes backed by rigorous material science.