If 6 holes are drilled on PCD of 120 mm, what will be the center distance between two adjacent (nearest) holes?

Concept:

Pitch Circle Diameter:

• Pitch Circle Diameter, which is the diameter of the circle that passes through the center of the bolt holes or studs on a hub or drum.
• This is the same as the mounting holes on a wheel rim.
• If ‘S’ is the distance between two adjacent studs/bolts or holes (measured in millimeters) then the PCD would be:
  • 4 studs/bolts or Holes = S / 0.7071
  • 5 studs/bolts or Holes = S / 0.5878
  • 6 studs/bolts or Holes = S / 0.5

Calculation:

Given:

PCD = 120 mm

For 6 studs/bolts or Holes, PCD = \(\frac{S}{0.5}\)

⇒ 120 = \(\frac{S}{0.5}\)

⇒ S = 120 × 0.5 = 60 mm

The center distance between two adjacent (nearest) holes is 60 mm.