AMS2750 is the standard that defines how heat treating furnaces and their measurement systems are controlled in aerospace. For a heat treating supplier it is one of the first topics looked at both in customer audits and in Nadcap.
The main topics of the standard
- Thermocouples and measuring instruments: Which type of sensor can be used for how long, and how it is calibrated.
- Instrumentation type: Which instruments the furnace has for control, recording and overtemperature protection.
- Furnace class: How narrow a range the furnace can hold its temperature within. The class determines which work can be done.
- SAT (System Accuracy Test): A test of whether the measurement system, as a whole, measures correctly.
- TUS (Temperature Uniformity Survey): A test of whether the temperature at every point in the furnace work zone stays within the limits.
Test intervals and limits depend on the furnace class and the instrumentation type; refer to the current revision.
Related reading: What is a TUS? · What is a SAT? · AMS2759 explained
Common mistakes
- Sensor locations and count missing from the TUS report
- Calibration correction factors not applied
- Missed test intervals
- Furnace class not matching the work being done
- Records kept by hand and lost
Which of these is in your records?
Most of these mistakes slip past when records are read by eye one at a time, and auditors look for them first. The real question is which one sits in your own files. Upload your furnace records to NTB SpecPro and quickly see which points may carry risk, the likely reason and a suggestion.
Evaluating records quickly
The NTB SpecPro heat treat module evaluates your furnace records and recipes against the relevant AMS standards, shows out-of-limit points and prepares a PDF report. Final evaluation stays with your authorized heat treating personnel.
Prepared by NTB SpecPro process quality engineering; reviewed by an engineer holding the International Welding Engineer (IWE) qualification. Questions: info@ntbspecpro.com
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