Heat Treatment Certification for AS9102 Form 2: Documentation Guide

A precision machine shop spent two weeks chasing a heat treatment certificate from their vendor. The vendor's certificates referenced an old revision of AMS 2750 (pyrometry standard for heat treatment) that had been superseded eighteen months earlier. The customer's auditor flagged it. The shop spent two weeks of phone calls before the right certification version arrived. The FAI submission was delayed by sixteen days. The customer issued a corrective action request for the supplier's vendor management process.

Heat treatment certification is the part of Form 2 that quietly delays more FAI submissions than any other single factor. The certificate must reference the correct revision of the governing specification, contain specific pyrometry compliance data, document the actual heat treat parameters used, and trace the lot through to the part serial numbers. Any one of these going wrong delays submission.

This guide covers heat treatment certification for AS9102 Form 2: what the certificate must contain, AMS 2750 pyrometry requirements, traceability requirements, common rejection reasons, and the documentation workflow that prevents the two-week-phone-call problem. The general Form 2 baseline is in AS9102 Form 1 vs Form 2 vs Form 3 Explained.

Heat Treatment Certification for AS9102 Form 2: The Required Content

A heat treatment certification on Form 2 must contain:

1. Heat Treatment Specification

The customer's drawing specifies which heat treatment is required (e.g., "Anneal per AMS 2770", "Age harden per AMS 2772", "Solution treat and age per AMS 4117 condition T6"). The certification must reference this specific specification with the correct revision.

2. Process Parameters

The actual heat treatment parameters used:

• Soak temperature and tolerance (e.g., 540°C ±10°C)

• Soak duration and tolerance (e.g., 2 hours ±15 min)

• Cooling method (air cool, water quench, oil quench, furnace cool)

• Ramp rates if specified

• Atmosphere (air, argon, hydrogen, vacuum)

3. AMS 2750 Pyrometry Compliance

AMS 2750 governs the calibration and validation of heat treat equipment. The certificate must include:

• Furnace pyrometry compliance reference (AMS 2750E or current revision)

• TUS (Temperature Uniformity Survey) date and results

• SAT (System Accuracy Test) date and results

• Class of the furnace (Class 1, 2, 3, 4 with progressively looser temperature uniformity)

• Type of instrumentation (Type A, B, C, D, E)

A heat treat vendor whose AMS 2750 compliance is current can perform aerospace heat treatment. A vendor without current AMS 2750 compliance cannot. The FAI documentation depends on this being verifiable.

4. Traceability to Lot and Serial Numbers

The heat treat certificate must link to the specific lot or serial numbers being heat treated. Generic "we heat treated parts" without lot identification fails traceability.

5. NADCAP Certification (where required)

For aerospace work, the heat treat vendor must be NADCAP-certified for heat treatment. The certificate references the NADCAP cert number, scope, and expiration. We covered NADCAP scope in NADCAP Special Process Requirements for AS9102 FAI and the audit prep in NADCAP Audit Preparation for Aerospace Shops.

6. Inspector and Approval Signatures

The certificate must be signed by the heat treat vendor's quality manager or designated inspector, with date and contact information.

AMS 2750 Pyrometry Requirements Explained

AMS 2750 is the pyrometry standard for heat treatment. It specifies how heat treat equipment must be calibrated and validated.

Furnace Classes

Class	Temperature Uniformity	Typical Application
Class 1	±3°C	Critical aerospace heat treatment
Class 2	±5°C	Most aerospace heat treatment
Class 3	±8°C	Lower-criticality aerospace work
Class 4	±14°C	Non-aerospace work
Class 5	±28°C	Heat treatment with very loose temperature requirements
Class 6	±42°C	Even looser

Aerospace work typically requires Class 1 or Class 2 furnaces. The drawing's heat treatment specification implies a class requirement.

Temperature Uniformity Survey (TUS)

A TUS measures temperature uniformity throughout the furnace work zone. It must be performed at the required frequency (typically every 6 months for Class 1, longer for lower classes) and the results must show the furnace meets its class tolerance.

System Accuracy Test (SAT)

A SAT verifies the accuracy of the temperature measurement system (thermocouples, instrumentation). It is performed quarterly for Class 1.

The Form 2 certification must reference the most recent TUS and SAT, with dates within the validity period.

Common Heat Treatment Form 2 Rejection Reasons

Wrong AMS 2750 revision. Certificate references AMS 2750D when current revision is AMS 2750E. The standard has updated requirements; the older revision is no longer valid.

Expired TUS or SAT. The certificate is signed but the underlying TUS is from 18 months ago when it should be every 6 months. Pyrometry compliance has lapsed.

Wrong furnace class. Customer's drawing implies Class 2 requirement; the heat treat was performed on a Class 4 furnace. Class does not meet requirement.

Missing lot traceability. Certificate is generic, does not reference specific lot or serial numbers. Cannot link the certification to the specific parts in this FAI.

Wrong cooling method. Customer drawing specifies water quench; vendor performed oil quench. Process deviation not documented.

NADCAP cert expired. Heat treat vendor's NADCAP cert lapsed at the time of inspection. Form 2 references invalid certification.

Vendor not on customer's approved supplier list. Heat treat performed by a vendor not on the customer's AVL (Approved Vendor List). Customer-specific supplier flow-down violated.

We covered the broader Form 2 issues in AS9102 Form 1 vs Form 2 vs Form 3 Explained and the corrective action workflow in AS9102 FAI Rejection Response and Corrective Action.

The Workflow That Prevents Heat Treatment Delays

The supplier who lost 16 days from the cert issue developed this workflow afterward:

1. Pre-Job Vendor Audit

Before sending parts to heat treat, confirm:

• Vendor's NADCAP cert is current with at least 60 days remaining

• Vendor's AMS 2750 compliance is current with at least 30 days remaining

• Vendor is on customer's AVL (where applicable)

• Vendor's class capability matches the requirement

If any of these fail, switch vendors before the lot ships, not after.

2. Heat Treat PO with Required Certification Statement

The purchase order to the heat treat vendor includes specific language requiring:

• Certificate referencing current AMS 2750 revision

• Traceability to lot numbers and customer serial numbers

• Specific pyrometry data (TUS, SAT)

• NADCAP cert number and expiration

• Inspector signature and date

The vendor returns parts plus a complete certificate, not parts alone. The certificate package becomes part of the FAI documentation flow.

3. Pre-FAI Certificate Review

Before FAI submission, the supplier's QE reviews the heat treat certificate for completeness. Missing fields are flagged and addressed before submission, not during customer review.

4. Vendor Management Reporting

Quarterly: review heat treat vendors for upcoming cert expirations. Replace vendors whose certs are at risk of lapsing during a known production schedule.

This is operational discipline. Suppliers who do this avoid the cert-chasing problem entirely. Those who do not, suffer the 16-day delays repeatedly.

When the Drawing Has Multiple Heat Treatment Requirements

Some parts have multiple heat treatment cycles (solution treat, age, stress relief, etc.). Each cycle requires its own Form 2 documentation. The certificate for each cycle is separate, even if the same vendor performs both.

We covered the specific MIL-A-8625 anodize follow-on documentation in Anodize Type 2 vs Type 3 for Aerospace Machined Parts and the material spec mapping in AMS Material Specifications for Aerospace CNC Machining.

Heat Treat Vendor NADCAP Audit Risk

If the heat treat vendor's NADCAP audit fails or finds significant issues, certifications issued during the affected period can be challenged retroactively. Suppliers using that vendor may find their FAI submissions questioned even though they were accepted at the time. This is rare but documented.

The defense for the supplier: maintain vendor management records that document due diligence at the time of vendor selection. If the supplier did appropriate vendor qualification, the supplier is shielded from the vendor's later issues. Records matter.

Mavlon Identifies Heat Treatment Requirements

Mavlon reads drawings for heat treatment specifications in the title block, general notes, and material specification references. Each heat treatment requirement becomes a Form 2 entry with the required documentation fields (specification, parameters, AMS 2750 pyrometry, traceability, NADCAP cert). The QE fills in actual cert data at submission time.

Upload a Drawing to see heat-treat-aware Form 2 generation.