Assuming you do not want to use any quick and dirty chemical tricks,
here's how to distinguish...
In my kit (a tri-gear, so I've not seen any tailwheel components) all Al
(most, if not all, is 6061 alloy) and steel (4130 is the only steel
alloy used) tubes had mill markings to identify the material. This is
the surest way to determine what's what. If you are lacking clear
markings, then....
If its bright and shiny (or at least clean looking) it's either Al or
SS, because all of the 4130 is dark, almost black. If there is any
doubt use a magnet since neither the Al nor the SS used in the kit is
magnetic. As I recall the only SS tube in the kit is the tailplane
torque tube (not having my inventory handy at the office I can't check
but it is probably TP16) as are its associated components. If there are
other SS parts, then note that Al has both lower density and lower
Young's modulus so it will feel lighter than SS and will be less stiff
in bending. The color and luster are also different, so find the
longest fattest piece of metal tube in your inventory and note its
appearance. It's Al. So are all of the bell cranks.
Once you have identified one piece of each material you will be able to
identify all others because the appearance of each metal is unique.
Best regards,
Rob Housman
A070
Subject: Identifying Alu and Steel parts
All:
I'm perusing my pack of parts, preparing to properly proof them
against corrosion (sorry, couldn't keep up the alliteration), and wonder
how one determines the difference between Aluminum, Steel, and Stainless
Steel. Aside from the obvious weight difference between Alu and Steel,
there appears to be a distinct grain to the surface of steel parts, but
not a clear difference between regular and Stainless steel.
In the tail kit, for example:
XTW12 - aluminum, by weight and lack of grain
XTW09 - steel, regular? by weight and grain
TP16 - steel, but Steve G. sez it's stainless
XA2 - aluminum
Any hints?
Thanks,
Shaun Simpkins
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