Metal finishing Q&As since 1989

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Safely marking aircraft engine turbine blades

Are there any "ink" based marking devices safe for this type of identification? I am in the business of supplying aircraft turbine engine components to commercial aircraft operators and suppliers. I use FAA certificated, third-party vendors, to perform repairs to various engine components. It is important to me to maintain an identification system for non-serialized items such as turbine blades. As an example, I need to know when I send out blades for repair that I will get the same blades in return. I understand some marking devices such as graphite based pencils can embrittle alloys like the ones used in turbine blades manufacture.

Andrew Ennes
aerospace supply - Buffalo Grove, Illinois, USA
2004

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First of two simultaneous responses --

The OEM for that blade will specify the allowable marking procedure. Anything else is absolutely not authorized. If an ink is authorized, it will be very precisely specified in a QPL and Standard Practice manual.

Any thing short of engraving will be removed by the FAA certified shop prior to their rework of the part. You are correct, you have only the reputation of the FAA shop to get your same parts back, and I would not bet much more than a cup of coffee on the honesty of some repair shops.

James Watts
- Navarre, Florida
2004

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Second of two simultaneous responses --

Andrew,

Why don't you ask Specialty Metals (or Wiggin Specialty Metals in the UK) ... after all, they are the people who make the Nimonic rotor turbine blades.

A marking ink? Wow. Wouldn't the heat destroy those markings? But maybe be OK for stator blades.

Could you not heat etch, ie. burn, a mark in the fir tree root? That wouldn't/shouldn't disturb the balance.

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).
2004