Medical Equipment · Mechanical Failure Analysis

$25,000 Annual Failure Cost Eliminated Through Smarter Material Selection

$25,000+

Annual Cost Saved

2.4×

Strength Increase

21 in-lbs

Failure Load

Executive Summary

A medical service provider was spending approximately $25,000 per year replacing repeatedly failing components inside an adjustable fixture assembly. The source of failure was traced to cast aluminum inserts that fractured under normal tightening loads. Design Iterative Analysis evaluated the failure mode, identified the weak link, and recommended a more durable replacement strategy — with the potential to eliminate a five-figure annual expense.

The Business Problem

Recurring Breakage

The aluminum inserts consistently failed in service under normal use.

Replacement Costs

New parts had to be continually purchased and stocked, adding up month after month.

Operational Disruption

Failures created unnecessary maintenance events and preventable interruptions for technicians.

The issue was not one catastrophic failure. It was death by repetition.

Root Cause Findings

Mechanical analysis identified localized stress concentration at the sharp tooth geometry of the cast inserts. The parts were vulnerable at approximately 21 in-lbs of rotational load — a level easily reached with standard hand tools.

In practical terms:
  • Normal use could damage the part
  • Casting variability increased inconsistency
  • The design had little margin for real-world handling

Material Selection

Our recommendation is to replace the cast aluminum with a machined billet component. The table below outlines the most viable material options evaluated.

MaterialKey FeatureStrength vs. Cast Al.Cost vs. Cast Al.Ranking
Carbon SteelLow Cost2.8×1.3–1.8×2
316 Stainless SteelCorrosion Resistance2.4×1.8–2.8×1 ★
TitaniumStrength + Corrosion Resistance4.2×5–8×3
InconelHeat + Strength + Corrosion Resistance5.0×10–15×4

Recommendation: Machine the insert out of 316 Stainless Steel — the best balance of durability, corrosion resistance, and lifecycle cost.

Result

A relatively small engineering decision had the potential to eliminate a five-figure annual expense. If a part keeps failing, costing money, or slowing production — every month it continues is money you never get back.

Got a recurring failure that's costing you?

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