Case Depth Testing Metallography Services for Aerospace & Oil & Gas 

Quantify Effective Case Depth Measurement: Accredited, Defensible, and Delivered Fast 

Why Case Depth Testing Matters 

In flight-critical and high-pressure assemblies, the hardened case supports wear resistance, contact fatigue life, and preload retention while the softer core maintains toughness. Insufficient or excessive case depth can trigger pitting, spalling, thread-root cracking, and premature failure—especially at bearing lands, splines, and first engaged threads. Quantified case depth confirms heat-treat effectiveness, validates stock-removal allowances, and underpins MRB decisions and OEM/FAA audits. 

AADFW’s Approach: Precision, Speed, and Proof 

• Accredited & precise: Work performed under ISO/IEC 17025 with controlled preparation, calibrated optics, and documented microhardness procedures. 

• Faster results: Alloy-specific prep/etch plans and decision-ready photo micrographs compress lead times without compromising rigor. 

• Trusted by engineers: Clear acceptance callouts tied to drawing/spec limits, location maps, and metallurgical interpretation that stands up to audits. 

Case Depth Testing Capabilities 

• Targeted Sectioning & Mounting 
  Non-thermal sectioning at highest-risk locations (thread roots, fillets, gear teeth, bearing surfaces) with orientation marks for repeatable measurements. 

• Preparation & Etching 
  Artifact-free grinding/polishing per ASTM E3 and alloy-appropriate etchants per ASTM E407 to reveal case/matrix features and aid hardness placement. 

Microhardness Profiling (Primary Method) 

• Vickers/Knoop traverses per ASTM E384 / ASTM E92 from surface to core to determine: 
  • Effective Case Depth (ECD): depth to the specified hardness criterion (e.g., HRC 50 equivalent or drawing-defined HV). 
  • Total Case Depth (TCD): depth to the inflection/transition when defined by spec. 
  • Surface/Core Hardness: verification against limits; gradient characterization for process health. 
• Feature-Specific Evaluations 
  Case depth at first engaged thread, bearing lands, and root radii where stress is highest; correlation to machining stock removal or chemical-mill allowances. 
• Optical Confirmation & Image Analysis 
  Calibrated scale bars, stitched panoramas, and measured callouts (avg./max.) for documentation; microstructure notes (carbide morphology, networking, over-carb). 
• Related Integrity Checks (as specified):
  • Decarburization assessment per ASTM E1077 (microhardness confirmation). 
  • Coating/Plating interfaces for bake effects or over-tempering. 
  • Chemistry (OES; C/S) for grade/baseline carbon; PT for surface-crack screening if required. 

• Reporting & Traceability (Audit-Ready) 
  Test plan, locations map, hardness-vs-depth plots, photo plates with etchant/time, instrument/calibration references, and full chain of custody. 

Industries We Support 

• Aerospace: Gears, bearings, actuators, pins/bolts, and structural hardware—case integrity aligned to OEM/FAA expectations. 

• Oil & Gas: Pressure-boundary bolting, valve components, and wear surfaces where case depth governs preload and service life. 

• Defense & Advanced Manufacturing: Mission-critical mechanisms (including AM base materials) needing repeatable surface properties and documented compliance. 
  Trusted by engineers and QC managers across mission-critical industries. 

Accreditations & Standards Compliance 

AADFW operates to ISO/IEC 17025 and supports Nadcap-driven program requirements, executing case-depth evaluations to the methods on our accredited scope and customer specifications, including: 

• ASTM E3 (metallographic specimen preparation) 

• ASTM E407 (micro-etching) 

• ASTM E384 / ASTM E92 (microhardness for case-depth determination) 

• ASTM E1077 (decarburization evaluation, when applicable) 

• Fastener/product-specific criteria (e.g., ASTM F2328 for decarb in carbon/alloy steel fasteners) and AMS/OEM case-depth requirements as specified in purchase documents. 

Why Engineers Choose AADFW 

• Accredited & audit-ready metallography with quantified, defensible measurements. 

• Faster turnaround—alloy-specific prep routes and standardized reporting keep project gates on schedule. 

• Trusted partner to aerospace and oil & gas QA organizations. 

• Expert metallurgists who convert micrographs and hardness data into clear go/no-go decisions and practical process guidance. 

Request a Quote for Case Depth Metallography Testing 

Protect fatigue life and surface performance with verified case profiles. Request a Quote to schedule case-depth evaluation today.