Question: What Do the Letters X, S, R, A and L Mean When They Appear on a Shaft?
(Editor's Note: Most shafts are designated with a letter code, the letters being X, S, R, A and L. What do these letters represent? Here is Tom's answer.)
Answer: Some golf shafts bend more than others, of course. The letter code represented by the letters L, A, R, S and X represents those different grades of flex.
"L" is the most flexible shaft and "X" is the stiffest shaft. "L" denotes "ladies flex"; "A" denotes "senior flex"; "R" denotes "regular flex"; "S" denotes "stiff flex"; and "X" denotes "extra stiff flex."
Why is senior flex represented by an "A"? When manufacturers first started using this code to denote the flex of their shafts, "A" stood for "amateur," but that level of flex later became associated with senior men.
See also: Are there industry standards for how flexible each level of flex (L, A, R, S, X) should be?
About the Author
Tom Wishon is one of the most highly respected members of the golf equipment industry. He specializes in clubhead design, shaft analysis, and clubfitting research and development, and is the owner of his own golf equipment company, Tom Wishon Golf Technology. Tom is a member of the Golf Digest Technical Panel, and is the Technical Advisor to PGA.com, the website of the PGA of America.

