Spring Tension Gram Gauge for measuring the tightness of piano action flanges.  Measures from 0-10 grams of tension.  Stainless Steel construction with a U-guard to help protect the pointer. 

Grand hammer flanges should generally have 2 to 4 grams of tension when measured at the screw hole.

Repetition levers with the spring disengaged should have approximately from 2 to 6 grams of tension.

The wippen flange should have from 2 to 4 grams of tension.