By Russ Ryden, Fit2Score, A Dallas Fort Worth Club Fitter & Builder
The Highlands Performance Golf Center, Carrollton Texas 
Golf Digest Certified America’s 100 Best Club Fitter

it hax been years since I measured a SteelFiber Shaft. True Temper acquiered Aerotech Golf in Demember 2019. I knew Chris Hilleary who launched Aerotech Golf in 2001 and passed away unexpectly in 2021. Its best to have Chris explain Steelfiber shafts:

Chris taught me how to measure hoop strength. I added hoop deformation into my software system. It later became essential for removing the distortion of EI measurements inherent in the 3-point process of measuring golf shafts. Textbook EI measurement is built around measuring solids. Golf shafts are tubes which deform during play as well as during measuring. After measuring distortion of a great number of shafts as each of the strain points, we learned we could forecast those distortions by applying known hoop deformationof the golf shaft tube.