To be quite honest you CAN calibrate any spine tester with just about any shaft. Aluminums are PERFECT for calibrating spine on a spine tester. You'll however need to know the exact spine for the type of shaft (ie xx75 vs GGII etc etc).

Arthur is right, Easton measures completely different then the typical wood arrow spine tester. However as long as you have the correct figures you can use this for your 26" spine tester. Meaning someone has already gone out and figured out what those spines are on a 26" style spine tester. I have a list of quite a few different arrows, none in legacy's, all xx75 or GGII's. If you can find either of these let me know and I'll help ya out.

The other thing you can do is buy some prespined shafts as test shafts from a company to use as calibration for your spine tester, and also use for tuning purposes on your bow.

Regardless how you go about things, make sure the figures you are getting are from a like tester. Ie Adams style to Adams style and dial indicator to dial indicator style.

Also there is a figure to get spine/deflection using 26" supports and for the life of me I cannot remember it. One of these years when they create the magic memory pill I might be able to remember...otherwise I'll have to post when I come acrossed it again.