Hole Arrangement & Open Area Formulas
Open Area is the ratio between the total area of the holes and total sheet area, normally it is expressed by percent.
Round Hole, 60° Staggered
(R2 X 90.69) / T2 = %
Round Hole, Straight Row
(R2 X 78.5) / (U1 X U2) = %
Round Hole, 45° Staggered
(R2 X 78.5) / (K1 X K2) = %
Square Hole, Straight Row
(C2 X 100) / (U1 X U2) = %
Square Hole, Staggered
(C2 X 100) / (0.5 X Z1 X Z2) = %
Round End Slot, Straight Row
((R X L - 0.215R2) X 100) / (U1 X U2) = %
Round End Slot, Z Type Staggered
((R X L - 0.215R2) X 100) / (0.5 X Z1 X Z2) = %
Round End Slot, K Type Staggered
((R X L - 0.215R2) X 100) / (0.5 X K1 X K2) = %
Square End Slot, Straight Row
(L X C X 100) / (U1 X U2) = %
Square End Slot, Z Type Staggered
(L X C X 100) / (0.5 X Z1 X Z2) = %
