How It Works
Hose Selection Criteria
Proper hose sizing considers three main factors: velocity limits, working pressure, and bend radius. This calculator focuses on velocity-based sizing.
SAE Dash Size System
SAE dash sizes indicate hose inside diameter in 1/16" increments:
- -4: 4/16" = 1/4" ID = 6.4mm
- -8: 8/16" = 1/2" ID = 12.7mm
- -12: 12/16" = 3/4" ID = 19mm
- -16: 16/16" = 1" ID = 25.4mm
Velocity-Based Selection
The minimum required ID is calculated from the flow rate and maximum allowable velocity:
ID_min = sqrt(4 * Q / (pi * V_max))
Where Q = flow rate, V_max = maximum velocity for line type
Velocity Guidelines by Line Type
- Suction Lines: Max 4 ft/s (1.2 m/s) - Prevents cavitation
- Return Lines: Max 10 ft/s (3.0 m/s) - Low pressure, heat dissipation
- Pressure Lines: Max 15-25 ft/s (4.5-7.6 m/s) - Depends on pressure
SAE 100R Series Hose Types
- 100R1: Single wire braid - General purpose, 3000-5000 psi
- 100R2: Double wire braid - Higher pressure, 3000-6000 psi
- 100R4: Suction/return - Low pressure with wire helix
- 100R12: Four spiral wire - Very high pressure 4000-5000 psi
- 100R13: Multiple spiral - Ultra high pressure 5000-6000 psi
Hose Sizing Calculator
Select the optimal hydraulic hose size based on flow rate and application. Includes SAE 100R series recommendations.
Lower velocity = larger hose, less pressure drop
Recommended Hose Size
-12
0.75" ID (19.0 mm)
Sizing Results
Minimum Required ID
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Flow Rate
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Velocity Limit
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Available Dash Sizes
SAE 100R Series Selection
| Type | Construction | Pressure (psi) | Application |
|---|---|---|---|
| 100R1 | 1 Wire Braid | 3000-5000 | General purpose |
| 100R2 | 2 Wire Braid | 4000-6000 | Higher pressure |
| 100R4 | Wire Helix | 150-300 | Suction/Return |
| 100R12 | 4 Spiral Wire | 4000-5000 | Compact high pressure |
| 100R13 | Multi-Spiral | 5000-6000 | Ultra high pressure |
| 100R15 | 6 Spiral Wire | 6000+ | Extreme pressure |
Pressure ratings vary by dash size. Always verify with manufacturer specifications.
SAE Dash Size Reference
| Dash | ID (in) | ID (mm) | Max GPM @ 4 ft/s | Max GPM @ 15 ft/s |
|---|---|---|---|---|
| -4 | 0.250 | 6.4 | 2.5 | 9.3 |
| -5 | 0.312 | 7.9 | 3.9 | 14.5 |
| -6 | 0.375 | 9.5 | 5.6 | 21.0 |
| -8 | 0.500 | 12.7 | 10.0 | 37.3 |
| -10 | 0.625 | 15.9 | 15.6 | 58.4 |
| -12 | 0.750 | 19.0 | 22.4 | 83.9 |
| -16 | 1.000 | 25.4 | 39.9 | 149.2 |
| -20 | 1.250 | 31.8 | 62.3 | 233.2 |
| -24 | 1.500 | 38.1 | 89.7 | 335.8 |
| -32 | 2.000 | 50.8 | 159.5 | 596.9 |