### Oblong hole in staggered row (LRZ)

#### Perforation mark: LR (w*l) Z (t1*t2)

• Open area (%): A0 = (w * l – 0,215 w2 / t1 * t2) * 100 u %
• Number of holes per m2: n = 1.000.000 / t1 * t2
• a2 = y * t1 + w
• y = number of distances t1 parallel to a2
• b2 = x * u + l
• x = number of distances u parallel to b2
• u = 0,5 t2
• Perforation direction: a1 ili b1

### Oblong hole in parallel row (LRU)

#### Perforation mark: LR (w*l) M (t1*t2)

• Open area (%): A0 = (w * l – 0,215 w2 / t1 * t2) * 100 u %
• Number of holes per m2: n = 1.000.000 / t1 * t2
• a2 = y1 * t1 + w
• y1 = number of distances t1 parallel to a2
• b2 = x1 * t2 + l
• x1 = number of distances t2 parallel to b2
• Perforation direction: a1 ili b1

### Oblong hole in staggered row (LRS)

#### Perforation mark: LR (w*l) S (t1*t2)

• Open area (%): A0 = (w * l – 0,215 w2 / 0,5(t1 * t2) * 100 u %
• Number of holes per m2: n = 1.000.000 / 0,5(t1 * t2)
• a2 = y * t1 + w
• y = number of distances t1 parallel to a2
• b2 = x * u + l
• x = number of distances u parallel to b2
• u = 0,5 t2
• Perforation direction: a1 ili b1 