http://www.usga.org/rules/equipment-rules.html#!rule-14615 false Supplement B Supplement B GROOVE MEASUREMENT DATA SHEET (Applies to Pre-2010 Groove Requirements) CLUB = __________ DATE = __________ LINE 1) Distance from groove 1 to groove 5 D = ______ 2) Maximum allowable groove width (D/16) = W max allow = ______ 3) W max allow + 0.002 = Upper limit = ______ 4) W max allow - 0.002 = Lower limit = ______ 5) Individual groove measurements: W1 = ______ W2 = ______ W3 = ______ W4 = ______ W5 = ______ 6) If any width W1 - W5 is greater than "W max allow +0.002 inches (Upper limit from line 3 above) then the club DOES NOT conform. 7) If all widths are less than "W max allow -0.002 inches (Lower limit from line 4 above) the club conforms. 8) If any groove width is between the Upper and lower limits, the club should be submitted to the USGA for a precise laboratory measurement and the player should be given a Duration of Competition Answer if the club has not been previously examined by the USGA. 9) The rule states that the minimum distance between grooves (land area) shall not be less than .075 inches and not less than three times the width of the groove. If the land area between any two grooves is less than .073 inches the club does not conform. If the distance is greater than .077 inches the club conforms to this part of the specification. If the distance is between .073 inches and .077 inches, submit the club to the USGA for a precise measurement.