### Square hole in straggered row (CT)

#### Perforation mark: C (w) T (t)

• Open area (%): A0 = (100 * w2) / t2 u %
• Number of holes per m2: n = 1.000.000/t2
• a2 = x * t + w
• x = number of distances t
• b2 = y * v + w
• y = number of distances v; v = 0,5t ; p = w + c
• rmax = 0,15 * w (radius of corner openings)
• Perforation direction: a1 ili b1

### Square hole in diagonal row (CD-M)

#### Perforation mark: CD (w) M (t)

• Open area (%): A0 = (100 * w2) / t2 u %
• Number of holes per m2: n = 1.000.000/t2
• a2 = Z1 * g + we
• Z1 = number of distances g parallel to a2
• b2 = Z2 * g + w
• Z2 = number of distances g parallel to b2
• g = 0,707t; p = w + c; we = 1,414w
• rmax = 0,15 * w (radius of corner openings)
• Perforation direction: a1 ili b1

### Square hole in the straggered row (CZ)

#### Perforation mark: C (w) Z (t1 x t2)

• Open area (%): A0 = (100 * w2) / 0,5 * (t1 * t2) u %
• Number of holes per m2: n = 1.000.000 : 0,5(t1 * t2)
• a2 = t1 * x + w
• x = number of distances t1
• b2 = t2 * y + w
• y = number of distances t2
• rmax = 0,15 * w (radius of corner openings)
• Perforation direction: a1 ili b1

### Square hole in parallel row (CU)

#### Perforation mark: C (w) U (t)

• Open area (%): A0 = (100 * w2) / t2 u %
• Number of holes per m2: n = 1.000.000 / t2
• a2 = x1 * t + w
• x1 = number of distances t parallel to a2
• b2 = x2 * t + w
• x2 = number of distances t parallel to b2
• t = w + c
• rmax = 0,15 * w (radius of corner openings)
• Perforation direction: a1 ili b1 