Square hole

Square holes in staggered rows (Qv)

 

 

 

 

 

 

 

Square holes in straight rows (Qg)

 

 

 

 

 

 

 

Square holes in diagonal staggered rows (Qd)

 

 

 

 

 

 

 

Definition of terms used

a0 = Relative open surface
a1 = 1st external dimension of plate (width of plate)
a2 = Dimension of perforated area parallel dimension a1
b1 = 2nd external dimension of plate (length of plate)
b2 = Dimension of perforated area parallel dimension b1
c = Width of bridge
c1 = Width of side bridge – long hole
c2 = Width of end bridge – long hole
e1, e2 = Width of plain margin parallel to long side
f1, f2 = Width of plain margin parallel to small side
l = Length of hole
s = Thickness of plate
t = Spacing
t1 = Side pitch – long hole
t2 = End pitch – long hole
w = Size of hole