Engineering Formulas Reference
Common mechanical and industrial engineering formulas
Centrifugal Force & G-Force
G-Force (Relative Centrifugal Force)
G = ω²r / g = (4π²n²r) / g
G = G-force (dimensionless)
ω = angular velocity (rad/s)
r = radius (m)
n = rotational frequency (Hz)
g = 9.81 m/s²
Simplified G-Force from RPM
G = (RPM)² × r × 1.118 × 10⁻⁵
Where r is in centimeters
RPM from G-Force
RPM = √(G × 89,456 / r)
Where r is in centimeters
Centrifugal Force
F = mω²r = m(2πn)²r
F = centrifugal force (N)
m = mass (kg)
Vibration Analysis
Vibrating Screen G-Force
G = (2πf)² × A / g
f = frequency (Hz)
A = amplitude (half of stroke) (m)
Natural Frequency (Simple)
fn = (1/2π) × √(k/m)
fn = natural frequency (Hz)
k = spring constant (N/m)
m = mass (kg)
Unbalance Force
F = U × ω² = U × (πn/30)²
U = unbalance (kg·m or g·mm)
n = speed (RPM)
Power & Torque
Power from Torque (Metric)
P (kW) = T × n / 9549
T = torque (N·m)
n = speed (RPM)
Power from Torque (Imperial)
HP = T × n / 5252
T = torque (lb·ft)
n = speed (RPM)
Torque from Power
T (N·m) = 9549 × P (kW) / n
Physical Constants
| Constant | Value (SI) | Value (Imperial) |
|---|---|---|
| Standard Gravity (g) | 9.80665 m/s² | 32.174 ft/s² |
| Pi (π) | 3.14159265... | 3.14159265... |
| RPM to rad/s | × π/30 | × 0.10472 |
| rad/s to RPM | × 30/π | × 9.5493 |