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AMS2750H (G) & Nadcap Compliance

Over the last decade Caltherm has grown into the UK’s leading supplier of Nadcap & AMS2750H (G) compliant Industrial Ovens and Furnaces. Driven by an obsession with quality, reliability and continually improving designs, Caltherm has become the ‘go to’ name for many Prime & Tier 1 Aerospace & Defence manufacturers.

The Nadcap program was created by the Performance Review Institute (PRI), it is designed to provide an accreditation and quality assurance framework for a defined range of ‘special processes and products’ that are used within the Aerospace and Defence sectors. The most common ‘Special Process’ in our industry is Heat Treatment. Originally sponsored by Boeing, the Nadcap program is now widely adopted by all Western Aerospace manufacturers.

Nadcap has become increasingly important in the aerospace sector with accreditation frequently being requested by companies such as: BAE Systems, GKN, GE Aviation, Rolls Royce, Boeing, Bombardier, Safran, Hamilton Sundstrand and Collins Aerospace. Manufacturers and end users must follow the requirements of the SAE Aerospace Standard Number AMS2750H (G). In this Standard oven and furnace types are classified by their temperature uniformity and the type of control instrumentation that they use.

AMS 2750G is a pyrometry specification that focuses on continual improvement in the Aerospace industry by employing procedures for calibration data, timelines, record archiving, thermocouple guidelines and applications, System Accuracy Testing (SAT) and Temperature Uniformity Surveys (TUS). The current revision is ‘F’ which came in to effect in 2020.

Caltherm has significant experience and expertise in supplying aerospace customers with oven and furnace systems designed for full AMS2750H (G) compliance. Below is a list of key information required to aid us in designing the right equipment for your process. If you’re uncertain of any of the required information, let us know, we will be more than happy to help.

For oven & furnace systems to conform with AMS2750H (G) the following have to be defined:

1. Temperature range of compliance
2. Class of temperature uniformity required – either Class 1, 2, 3, 4, 5 or 6 (see table below)

AMS2750H (G) / Nadcap Instrumentation Reference Table	Inst. Type
AMS2750H (G) / Nadcap Instrumentation Reference Table	A	B	C	D	E
Each control zone has a thermocouple connected to the controller	X	X	X	X	X
Recording of the temperature measured by the control thermocouple	X	X	X	X
Sensor for recording the coldest and hottest spots	X		X
Each control zone has a charge/load thermocouple with recording system	X	X
Each control zone has an over temperature protection device	X	X	X	X

3. Temperature Instrumentation type – either Type A, B, C, D, D+ or E (see table below)
4. Uniform zone required – define H x W x D

Oven / Furnace Class	Temperature Uniformity
	°C	°F
1	± 3	± 5
2	±5 or ± 6	± 10
3	±7 or ± 8	± 15
4	± 10	± 20
5	± 14	± 25
6	± 28	± 50

Aerospace Prime Specifications

In addition to AMS 2750H (G) and Nadcap, most Aerospace manufacturers have their own specifications that you must meet in order to run their parts. In many cases, the Aerospace prime specifications are stricter than that required for AMS 2750H (G) and Nadcap certification. Best practice would be to make sure you are certified to the strictest specifications related to your customer’s requirements and processes.

Derivatives

These are some of the other derivatives of AMS2750 that we are asked to comply with, when designing an oven or furnace for a specific application.
AMS2769 – Heat Treatment of Parts in a Vacuum
AMS2770 – Heat Treatment of Wrought Aluminium Alloy
AMS2771 – Heat Treatment of Alloy Castings
AMS3025 – Polyalkalene Glycol Heat Treat Quenchant

CQI-9

What is CQI-9? – Continuous Quality Improvement (CQI) was published by AIAG (Automotive Industry Action Group). CQI-9 is based on the above described AMS2750, it was published in response to a realisation that the automotive industry needed top up its game, so they looked to the aerospace industry for guidance.
CQI-9 defines the fundamental requirements for heat treat management systems, addresses the process approach to automotive production, mandates an annual self-assessment, and provides for continual improvement.

The CQI-9 Requirement is applicable to first tier commercial heat treaters and captive heat treaters, to the OEM automotive industry as well as second tier heat treaters that provide service to first tier suppliers. Third tier heat treaters may be required to adhere to the CQI-9 requirements, but it is not mandatory unless requested.