Calculating...
Enter values to calculate
How It Works
Barlow's Formula
Barlow's formula calculates the hoop stress in a thin-walled tube under internal pressure, and is the basis for determining minimum wall thickness:
t = (P * OD) / (2 * S)
Where: t = wall thickness, P = internal pressure, OD = outside diameter, S = allowable stress
Burst Pressure
The theoretical burst pressure is calculated using the material's ultimate tensile strength:
P_burst = (2 * UTS * t) / OD
Where UTS = ultimate tensile strength of the material
Safety Factor
Hydraulic systems typically use a 4:1 safety factor (working pressure = burst pressure / 4):
- 4:1 - Standard hydraulic systems, SAE requirement
- 3:1 - Some high-pressure applications (verify with standards)
- 5:1 or higher - Critical safety applications, fatigue loading
Material Selection
- Carbon Steel (ASTM A513): Most common, good strength, 70,000 psi UTS
- Stainless Steel 304: Corrosion resistant, 75,000 psi UTS
- Stainless Steel 316: Better corrosion resistance, 75,000 psi UTS
- Aluminum 6061-T6: Lightweight, 45,000 psi UTS
Tube Wall Thickness Calculator
Calculate minimum wall thickness for hydraulic tubing using Barlow's formula with safety factors.
Material Selection
Enter actual tube wall to check if it meets requirements
✓
Wall Thickness Results
Minimum Wall Thickness
--
Suggested Tube Spec
--
Pressure Capacity
0
Working: 3000 psi
Burst: 12000 psi
Burst Pressure (theoretical)
--
Working Pressure (with SF)
--
Safety Factor Used
--
Inside Diameter
--
Standard Steel Tube Sizes
| OD | Wall | ID | Working @ 4:1 |
|---|---|---|---|
| 3/8" | 0.035" | 0.305" | 6,533 psi |
| 1/2" | 0.035" | 0.430" | 4,900 psi |
| 1/2" | 0.049" | 0.402" | 6,860 psi |
| 5/8" | 0.049" | 0.527" | 5,488 psi |
| 3/4" | 0.049" | 0.652" | 4,573 psi |
| 3/4" | 0.065" | 0.620" | 6,067 psi |
| 1" | 0.049" | 0.902" | 3,430 psi |
| 1" | 0.065" | 0.870" | 4,550 psi |
| 1" | 0.083" | 0.834" | 5,810 psi |
| 1-1/4" | 0.065" | 1.120" | 3,640 psi |
| 1-1/2" | 0.065" | 1.370" | 3,033 psi |
| 1-1/2" | 0.083" | 1.334" | 3,873 psi |
Based on carbon steel with 70,000 psi UTS and 4:1 safety factor
Material Properties Reference
| Material | UTS (psi) | Yield (psi) | Notes |
|---|---|---|---|
| Carbon Steel (A513) | 70,000 | 50,000 | Most common |
| 304 Stainless | 75,000 | 30,000 | Corrosion resistant |
| 316 Stainless | 75,000 | 30,000 | Marine/chemical |
| Aluminum 6061-T6 | 45,000 | 40,000 | Lightweight |