Hydraulic Press Design Calculator

Cylinder Calculation

Cylinder sizing, forces, piston rod, bolt and body strength.

💠 Input Parameters

Nominal force PkN

Liquid pressure pMPa

Max piston speedmm/s

Fill valve flow velocitymm/s

Head bolt quantitypcs

Bolt inner diametermm

Seal diameter (bolt circle)mm

Bolt yield strength σsMPa

Preload coefficient λ

Load-distribution factor C

Allowable stress ampl. σaMPa

Cylinder wall thicknessmm

Cylinder material allowableMPa

Piston rod Ømm

Rod unsupported lengthmm

Rod yield strength σsMPa

📊 Results

Cylinder bore (from P & p)mm

Fill valve diametermm

Head bolt tensile stressMPa<100 / <120

Max bolt load / boltkN

Mean bolt stress σmMPa

Stress amplitude σaMPaσa

Fatigue safety factor×≥1.2

Cylinder hoop stress (Lame)MPaallowable

Piston rod stress (upright)MPa<0.6·σs

Critical buckling loadkN

Buckling safety factor×≥3.5

Return/press area ratio×≥1.0

📌 Note

Bolt allowable: tensile stress <100 MPa for bolts ≤M12, <120 MPa for bolts >M12. Hoop stress formula: σ = p·(D_o²+D²)/(D_o²−D²), D_o=D+2t.

Fill valve diameter d_v = sqrt(4·v·A/(π·v_valve)), A = P·10³/p

Rod σ = P·10³/A_rod; Euler F_cr = π²·E·I/(μ·L)² (μ=2, fixed–free); return ratio = A_bore/(A_bore−A_rod).

Bolt: F_w=p·A_seal/n, F₀=λ·F_w, F_max=F₀+C·F_w. σ_a=(σ_max−σ_min)/2. Goodman σ_a/σ_Sa+σ_m/σ_s≤1.

🗺️ Schematic

Cylinder