**Related Resources: calculators**

### Birnie's Formula and Calculator for Thick-walled Cylinders of Ductile Material

**Fluids Engineering and Design**

**Pressure Vessels Design and Engineering **

**Thick-walled Cylinders of Ductile Material, Open Ends Birnie's Formula and Calculator**

**Birnie's Formula** is applicable to cylinders with open ends made of ductile materials. Maximum principal strain theory is taken in this case

A cylinder is considered to be thin-walled when the ratio of wall thickness to inside diameter is 0.1 or less and thick-walled when this ratio is greater than 0.1. Materials such as cast iron, hard steel, and cast aluminum are considered to be brittle materials; low-carbon steel, brass, bronze, etc. are considered to be ductile.

Preview: **Birnie's equation thick-walled cylinders of ductile material Calculator**

Where:

p = internal pressure, psi;

D = inside diameter of cylinder,
inches;

t = wall thickness of cylinder, inches;

S = allowable tensile stress, psi.

μ = Poisson’s ratio, = 0.3 for steel, 0.26 for
cast iron, 0.34 for aluminum and brass;

If metric SI units are used, then:

p = internal pressure in newtons per square meter

D = internal diameter of shell in meter

S = safe tensile stress in newtons per square meter

t = thickness of metal in the shell, in meter

Reference: Machinerys Handbook 30th Edition

Related:

- Clavarinos equation thick-walled cylinders of ductile material Calculator
- Lames's Formula Thick-walled cylinders equation and calculator
- Pressure Vessel External Pressure Calculations
- Pressure Vessel , Thin Wall Hoop and Longitudinal Stresses Equation and Calculator
- Dished Head Equation and Calculator Pressure Vessel Equations and Calculator