Hello, I have the Maltby Bench top club ruler, it is 1/2″ long in every measurement.
For example, if you put a 6 iron at 37.50″ into unit, it will state the club is 38.00″.
Why? Can’t be user error, the only adjustment is the lie angle.
You are probably measuring down the back of the shaft. The bench ruler is set up to measure down the middle of the shaft.