Overview of AC7102

AC7102 is the baseline checklist used during all NADCAP heat treat audits. Every supplier pursuing heat treat accreditation must complete AC7102 regardless of the specific thermal processes being performed.

Additional slash sheets are added depending on process scope:

Checklist	Application
AC7102	Baseline heat treating requirements
AC7102/1	Furnace brazing
AC7102/2	Aluminum heat treatment
AC7102/5	Hardness and conductivity testing
AC7102/8	Pyrometry

The checklist structure helps suppliers organize internal audits and identify process gaps before the official PRI audit.

Structure of AC7102

AC7102 is divided into 10 primary sections covering:

• Audit preparation
• Quality systems
• Personnel qualification
• Process control
• Testing systems
• Furnace control
• Vacuum furnace operation
• Documentation and traceability

Many questions include a (UXY) designation, meaning all suppliers must answer those questions regardless of process applicability.

Section 1 — NADCAP Audit Requirements

The first section focuses on the supplier’s internal self-audit process.

Suppliers are required to:

• Perform a complete internal audit before the PRI audit
• Use all applicable checklists
• Include required job audits
• Document procedures and paragraph references
• Address all internal non-conformances

Question 1.1.1 — Internal Self-Audit

This is one of the most common audit findings because suppliers often fail to complete all required job audits.

If your scope includes:

• AC7102 baseline
• AC7102/2 aluminum heat treat
• AC7102/8 pyrometry

then all related job audits must also be completed before the NADCAP audit.

Question 1.1.2 — Corrective Actions

All non-conformances discovered during the internal audit must be formally corrected through the supplier’s corrective action system before the PRI audit begins.

Poor Practice	Best Practice
Identifying findings only	Root cause analysis and documented closure
No corrective evidence	Objective evidence attached
Temporary fixes	Permanent systemic correction

Question 1.1.3 — Documents Required Before Audit

Suppliers must provide documentation at least 30 days before the audit.

Quality System Requirements

Question 3.4.1 — Previous Corrective Actions

Suppliers must demonstrate that all previous NADCAP corrective actions remain fully implemented.

“Failure to sustain previous corrective actions often results in major findings and reduced merit status.”

Common issues include:

• Expired calibration intervals
• Uncontrolled procedure revisions
• Incomplete SAT records
• Thermocouple replacement failures

Question 3.9.2 — Consumable Goods

Consumables must be controlled using documented procedures.

Consumable	Control Requirement
Quench oil	Certification review
Thermocouples	Calibration verification
Atmosphere gases	Purity validation
Salts	Composition verification

Personnel Requirements

Question 4.1.1 — Personnel Competency

NADCAP requires documented training procedures for:

• Contract review personnel
• Job planners
• Furnace operators
• Quality personnel
• Testing personnel

Continuous Improvement

Personnel evaluations must support continuous improvement programs.

Training records should include:

• Initial training
• Practical evaluation
• Requalification intervals
• Supervisor reviews
• Skill assessments

Process Control Testing

Suppliers must maintain documented process control testing systems.

Process Test	Purpose
Hardness testing	Verify heat treatment results
Mechanical testing	Validate material properties
Alpha case testing	Titanium contamination verification
Furnace burnout testing	Atmosphere cleanliness validation

Furnace Control and Maintenance

Question 9.1.2.1 — Heat-Up and Soak Parameters

Internal procedures must define:

• Heat-up rate
• Start of soak time
• End of soak time
• Cooling rate

For example:

The soak period typically begins when:

• All furnace thermocouples reach minimum setpoint temperature
• Load thermocouples stabilize within tolerance

Vacuum Furnace Requirements

Vacuum heat treatment is widely used for aerospace materials such as:

• Inconel 718
• Ti-6Al-4V
• 9310 steel
• 17-4 PH stainless steel

Question 11.2.1.2 — Vacuum Calibration

Vacuum instrumentation calibration is one of the most common findings during audits.

Vacuum Parameter	Typical Requirement
Vacuum level	10⁻⁴ to 10⁻⁵ torr
Dew point	Below -60°F
Leak integrity	Validated periodically

Importance of Job Audits

Job audits verify actual process execution using real production jobs.

AC7102 job audits include:

• Short-cycle jobs
• Long-cycle jobs
• Multi-stage thermal cycles
• Export-controlled jobs

AC7102/1 — Furnace Brazing

Furnace brazing falls under the heat treat commodity because it uses thermal processing equipment.

Critical Brazing Requirements

• Braze Process Specification (BPS)
• Braze Qualification Record (BQR)
• Dew point monitoring
• Braze filler metal control
• Vacuum furnace validation

Dew Point Monitoring

Dew point monitoring is frequently overlooked.

Requirement	Purpose
Dew point monitoring	Atmosphere moisture control
Monitoring location	Gas integrity validation
Documented frequency	Audit traceability

AC7102/2 — Aluminum Heat Treatment

Aluminum heat treatment is extremely sensitive to temperature variation.

“Even small temperature deviations can cause incipient melting in aluminum alloys.”

Because of this sensitivity:

• Class 2 furnaces are typically required
• Quench delay must be tightly controlled
• Quench agitation is critical
• Part spacing affects heat transfer

Quench Delay Control

Parameter	Importance
Door-open to immersion time	Controls final properties
Agitation	Improves cooling consistency
Quench temperature	Reduces cracking/distortion

AC7102/5 — Hardness & Conductivity Testing

Hardness testing validates final heat treatment effectiveness.

Common Audit Findings

• Missing direct verification records
• Improper indenter spacing
• Incomplete maintenance documentation
• Incorrect ASTM revision usage

AC7102/8 — Pyrometry

Pyrometry is one of the most critical areas of NADCAP compliance.

It ensures:

• Temperature accuracy
• Uniform heating
• Reliable instrumentation
• Repeatable heat treatment cycles

Key Pyrometry Areas

Pyrometry Element	Purpose
System Accuracy Test (SAT)	Verify sensor accuracy
Temperature Uniformity Survey (TUS)	Validate furnace consistency
Instrument calibration	Ensure traceable measurements
Thermocouple management	Maintain reliable sensing

Temperature Uniformity Surveys

TUS frequency depends on furnace class and instrumentation type.

Furnace Class	Temperature Tolerance
Class 1	±5°F
Class 2	±10°F
Class 3	±15°F

Common Pyrometry Findings

• Incorrect thermocouple insertion depth
• Missing SAT documentation
• Improper calibration labels
• Missing TUS diagrams
• Calibration range mismatch

Most Common NADCAP Heat Treat Findings

Finding	Root Cause
Incomplete self-audit	Missing checklist coverage
Calibration issues	Expired instruments
Incorrect SAT execution	Poor procedures
Missing training records	Weak personnel system
Improper TUS documentation	Incomplete diagrams
Consumable control failure	Unverified certifications

Best Practices for NADCAP Success

FAQ

Final Thoughts

NADCAP heat treating accreditation is far more than an audit requirement — it is the foundation of aerospace process reliability.

Understanding AC7102 and its related slash sheets allows suppliers to:

• Reduce audit findings
• Improve process control
• Enhance aerospace compliance
• Maintain OEM approvals
• Reduce scrap and rework
• Improve thermal processing consistency

By implementing robust internal procedures, maintaining strong pyrometry controls, validating personnel competency, and continuously improving process systems, aerospace heat treatment suppliers can successfully maintain NADCAP accreditation and meet the demanding quality standards of the aerospace industry.