Mounting pressure calculator

The pressure at the specimen is not the pressure in your air line. This calculator converts between the two: enter your cylinder and line pressure to find the effective mounting pressure at the mould face, or enter a target mounting pressure to find the ideal cylinder bore it requires.

Cylinder (actuator) bore diameter

The piston diameter of the pneumatic or hydraulic cylinder.

Line pressure (pneumatic or hydraulic)

Supply pressure into the cylinder — e.g. ~6 bar plant air. Not the mounting pressure.

Mould diameter

Common sizes: 25, 30, 32, 38, 40, 50 mm.

Advanced: include an estimated efficiency / loss factor

Cylinder area: 17,671 mm²
Actuator force: 10.6 kN
Mould area: 707 mm²
Effective mounting pressure (ideal): 150 bar
≈ in MPa: 15 MPa

Theoretical / ideal calculated values. Friction, seal losses, mechanism geometry, actual piston area, rod-side actuation and regulator behaviour alter real results. Not a certified machine specification.

Carry the calculated line pressure, mould diameter and target mould-face pressure into your machine configuration.

Use these values in my configuration

The formulas used

Cylinder area   A_cyl   = π × D_cyl²  / 4
Actuator force  F       = P_line × A_cyl × η
Mould area      A_mould = π × D_mould² / 4
Mould pressure  P_mould = F / A_mould = η × P_line × (D_cyl / D_mould)²

Ideal, loss-free relationships for a direct-acting cylinder. The optional efficiency factor scales actuator force linearly.

For background on why these quantities must never be conflated, read Metallographic Mounting Pressure Explained and the Temperature & Pressure Guide. For actuation trade-offs, see Pneumatic vs Hydraulic.