Understanding hydraulic hose dash sizes is fundamental for anyone working with fluid power systems. These numbers, often seen as -4, -8, or -16, directly relate to the hydraulic hose’s Inner Diameter (ID), which is crucial for optimal fluid flow and system performance. Correctly interpreting dash sizes ensures you select the right hose to prevent issues like pressure drop or overheating.
Choosing the appropriate ID based on dash size is more than just a measurement; it’s about matching the hose to your system’s flow rate and pressure requirements. This quick guide will demystify hydraulic hose dash sizes, empowering you to make informed decisions for efficient and reliable hydraulic operations, saving you time and preventing costly errors.
What is Dash Size?
Dash size is a numerical system used to represent the approximate outside diameter of hydraulic hoses. It’s a convenient and standardized method for quickly identifying hydraulic hose sizes, especially in the field or when referring to catalogs and specifications.
The dash number corresponds to the hose’s outside diameter in eighths of an inch. For example, a hose with a dash number of 8 has an outside diameter of 8/8 inches, or 1 inch.
Here’s a breakdown of how dash numbers relate to hose diameters:
- Dash 4: 4/8 inch (1/2 inch)
- Dash 6: 6/8 inch (3/4 inch)
- Dash 8: 8/8 inch (1 inch)
- Dash 10: 10/8 inch (1 1/4 inches)
- Dash 12: 12/8 inch (1 1/2 inches)
- And so on…
While dash numbers provide a general indication of hose size, it’s important to note that they don’t always precisely match the exact outside diameter due to manufacturing tolerances and variations between different hose brands. For critical applications or when precise dimensions are required, referring to our hydraulic hose manufacturer‘s specifications is essential.
How Hydraulic Hose Dash Sizes Work?
Hydraulic hose dash sizes are a standardized, shorthand way to denote the Inner Diameter (ID) of a hydraulic hose. This system simplifies the selection process by consistently representing the ID in increments of 1/16th of an inch.
So, a dash size of “-4” means the hose has an ID of 4/16ths of an inch (or 1/4 inch), a “-8” indicates 8/16ths of an inch (or 1/2 inch), and so on. This universal measurement method ensures that regardless of the manufacturer or specific hose type, a given dash size will always correspond to the same internal diameter, making it easy for users to identify and select the correct hose for their hydraulic system’s flow requirements.
Here’s a breakdown of how it works:
- Fractional Measurement: Each dash number represents the numerator in a fraction where the denominator is always 16.
- Inner Diameter (ID): For hydraulic hoses, dash sizes specifically refer to the hose’s inner diameter, which is the crucial measurement for fluid flow.
- Standardization: This system provides a consistent and widely recognized method across the industry, simplifying ordering and preventing sizing errors.
- Example: A “-12” dash size means the hose ID is 12/16ths of an inch, which simplifies to 3/4 inch.
Hydraulic Hose Dash Sizes in MM
While hydraulic hose dash sizes are primarily based on imperial measurements (1/16th of an inch increments), it’s often necessary to convert these to millimeters (mm), especially when working with global standards or metric system equipment. To convert a dash size to millimeters, you first convert the dash size to inches (by dividing the dash number by 16) and then multiply the resulting inch measurement by 25.4 (since 1 inch = 25.4 mm). This conversion is crucial for ensuring compatibility with metric fittings and system components, as well as for precise design and maintenance in international applications.
Here’s how the conversion works:
- Dash Number / 16 = Inner Diameter in Inches
- Inner Diameter in Inches * 25.4 = Inner Diameter in Millimeters
Below is a table illustrating common hydraulic hose dash sizes and their corresponding Inner Diameters in both inches and millimeters:
| Dash Size | Inner Diameter (Inches) | Inner Diameter (mm) |
| -2 | 1/8″ | 3.2 |
| -3 | 3/16″ | 4.8 |
| -4 | 1/4″ | 6.4 |
| -5 | 5/16″ | 7.9 |
| -6 | 3/8″ | 9.5 |
| -8 | 1/2″ | 12.7 |
| -10 | 5/8″ | 15.9 |
| -12 | 3/4″ | 19.1 |
| -16 | 1″ | 25.4 |
| -20 | 1-1/4″ | 31.8 |
| -24 | 1-1/2″ | 38.1 |
| -32 | 2″ | 50.8 |
Hydraulic Hose Dash Size Chart
Dash size is a numerical system used to denote the approximate outside diameter (OD) of hydraulic hoses. It serves as a quick reference for identifying hose sizes, especially in the field or when consulting catalogs.
Key Points to Remember
- Dash sizes for fittings are slightly different from those for hoses. Fittings often have two sizes: one for the fitting end connection and one for the hose size.
- Industry standard numbers for hoses typically refer to the inside diameter (ID) in sixteenths of an inch. However, there are exceptions like SAE 10R5, SAE 100R14, SAEJ51, and SAEJ2064 hoses, where the dash number indicates the hose ID is equal to the OD.
- Hoses and fittings are measured differently: Hoses are measured by their inside diameter (ID), while fittings are measured by their outside diameter (OD).
- Hoses can vary in flexibility: While the term “hose” often implies flexibility, there are both flexible and rigid hoses available. Nylon tubing is an example of a flexible hose, while flexible metal hoses are relatively rigid.
Here is the hydraulic hose dash size chart
| Dash No. | Inches | Millimeters | Inches | Millimeters |
|---|---|---|---|---|
| -2 | 1/8 | 3.2 | – | – |
| -3 | 3/16 | 4.8 | – | – |
| -4 | 1/4 | 6.4 | 3/16 | 4.8 |
| -5 | 5/16 | 7.9 | 1/4 | 6.4 |
| -6 | 3/8 | 9.5 | 5/16 | 7.9 |
| -8 | 1/2 | 12.7 | 3/8 | 9.5 |
| -10 | 5/8 | 15.9 | 1/2 | 12.7 |
| -12 | 3/4 | 19 | 5/8 | 15.9 |
| -14 | 7/8 | 22.2 | 3/4 | 19 |
| -16 | 1 | 25.4 | 7/8 | 22.2 |
| -20 | 1-1/4 | 31.8 | 1 | 25.4 |
| -24 | 1-1/2 | 38.1 | 1-1/8 | 28.6 |
| -32 | 2 | 50.8 | 1-3/8 | 34.9 |
| -40 | 2-1/2 | 63.5 | 1-1/2 | 38.1 |
| -48 | 3 | 76.2 | 1-3/4 | 44.5 |
| -56 | 3-1/2 | 88.9 | 2 | 50.8 |
| -64 | 4 | 101.6 | 2-1/2 | 63.5 |
| -72 | 4-1/2 | 115.2 | 2-3/4 | 71.4 |
Hydraulic Hose Dash Sizes Calculator
The Hydraulic Hose Dash Sizes Calculator provides a simple and efficient way to determine the precise Inner Diameter (ID) of a hydraulic hose, whether you’re working with imperial dash sizes or need to convert to millimeters. Instead of manually performing calculations, this tool allows you to input a dash size and instantly see its corresponding ID in both inches and millimeters, or vice-versa.
This functionality is invaluable for engineers, technicians, and anyone involved in hydraulic system design, maintenance, or repair, ensuring accuracy and saving time by eliminating the need for mental math or reference charts.
Hydraulic Hose Dash Sizes Calculator
Hydraulic Hose Dash Sizes Metric
While the dash size system is based on imperial measurements, many hydraulic systems and components, especially those used internationally, operate with metric dimensions. Therefore, it's essential to understand how to convert hydraulic hose dash sizes into millimeters (mm) for accurate selection and compatibility. This conversion involves a simple two-step process: first, interpret the dash size as a fraction of an inch (e.g., -8 is 8/16ths of an inch), and then multiply that inch value by the conversion factor of 25.4 (since 1 inch equals 25.4 mm).
This direct conversion ensures that you can precisely match hoses to metric fittings, ports, and design specifications, avoiding potential issues with leaks, flow restrictions, or improper assembly in metric-based hydraulic systems.
Here's how the conversion works:
- Dash Number / 16 = Inner Diameter in Inches
- Inner Diameter in Inches × 25.4 = Inner Diameter in Millimeters
Below is a table illustrating common hydraulic hose dash sizes and their corresponding Inner Diameters in both inches and precise millimeters:
| Dash Size | Inner Diameter (Inches) | Inner Diameter (mm) |
| -2 | 1/8" | 3.18 |
| -3 | 3/16" | 4.76 |
| -4 | 1/4" | 6.35 |
| -5 | 5/16" | 7.94 |
| -6 | 3/8" | 9.53 |
| -8 | 1/2" | 12.70 |
| -10 | 5/8" | 15.88 |
| -12 | 3/4" | 19.05 |
| -14 | 7/8" | 22.23 |
| -16 | 1" | 25.40 |
| -20 | 1-1/4" | 31.75 |
| -24 | 1-1/2" | 38.10 |
| -32 | 2" | 50.80 |
Why is it Important to use the Correct Hydraulic Hose Dash Size
Here is the Importance of the Correct Hydraulic Hose Dash Size
Selecting the appropriate hydraulic hose dash size is crucial for several reasons:
1. Performance and Efficiency:
- Proper Flow: A hose that is too small can restrict fluid flow, leading to reduced system performance and increased pressure drop.
- Pressure Integrity: A hose that is too large may not be able to withstand the required pressure, potentially resulting in leaks or bursts.
2. Safety:
- Burst Prevention: Using a hose that is undersized can increase the risk of bursting, especially under high pressure conditions. This can lead to serious injuries or equipment damage.
- Leak Prevention: A well-fitted hose helps prevent leaks, which can waste fluid, contaminate the system, and create safety hazards.
3. Equipment Life:
- Reduced Wear and Tear: A properly sized hose minimizes stress on the hose and fittings, extending their lifespan and reducing maintenance costs.
- System Protection: A correctly sized hose helps protect other components in the hydraulic system from damage caused by excessive pressure or fluid flow issues.
4. Cost-Effectiveness:
- Avoidance of Failures: Using the correct hose size helps prevent premature failures, saving money on replacement costs and downtime.
- Energy Efficiency: A properly sized hose can contribute to energy efficiency by minimizing pressure losses and optimizing system performance.
Choosing the right hydraulic hose dash size ensures optimal performance, safety, and cost-effectiveness in hydraulic systems. By carefully considering the abovementioned factors, you can make informed decisions and avoid potential problems associated with improperly sized hoses.
What size hose is Dash 8?
A hydraulic hose with a Dash 8 designation has an Inner Diameter (ID) of 8/16ths of an inch. This simplifies to 1/2 inch. This standardized dash sizing system allows for easy and consistent identification of a hose's internal diameter, which is critical for ensuring proper fluid flow and system performance.
What size is a Dash 12 hose?
A hydraulic hose with a Dash 12 designation has an Inner Diameter (ID) of 12/16ths of an inch. When simplified, this means a Dash 12 hose has an ID of 3/4 inch. This standardized sizing system is essential for accurately matching hoses to the flow rate and pressure requirements of hydraulic systems, ensuring optimal performance and preventing issues caused by undersized or oversized hoses.
What size is a dash 6 hose?
A hydraulic hose designated as Dash 6 has an Inner Diameter (ID) of 6/16ths of an inch. This fraction simplifies to 3/8 of an inch. This standardized measurement is crucial for proper hose selection, as the ID directly impacts the flow rate and pressure within a hydraulic system, ensuring it operates efficiently and without issues like excessive heat or pressure drop.
What is the difference between Dash 7 and Dash 8?
The fundamental difference between Dash 7 and Dash 8 hydraulic hoses lies in their Inner Diameter (ID). The dash sizing system indicates the ID in 1/16th-inch increments. Therefore, a Dash 7 hose has an ID of 7/16ths of an inch, while a Dash 8 hose has an ID of 8/16ths of an inch, which simplifies to 1/2 inch. This seemingly small difference in ID is significant for hydraulic system performance, as it directly impacts flow rate, pressure drop, and overall efficiency. A Dash 8 hose will allow for a higher volume of fluid flow compared to a Dash 7 hose under the same pressure conditions.
Conclusion
Understanding hydraulic hose dash sizes is fundamental for selecting the right hose for your specific application. By knowing the relationship between dash numbers and hose dimensions, you can ensure proper fit, performance, and safety.
Remember, the dash size is a crucial factor to consider when designing or maintaining hydraulic systems. Always refer to the manufacturer's specifications for accurate sizing information and to avoid potential problems associated with improperly sized hoses.
Ready to access our comprehensive hydraulic hose dash size chart? Visit our official website today! Our chart provides detailed information on various hose sizes and their corresponding dash numbers, making it easy to select the perfect hose for your needs.
Don't compromise on the performance and safety of your hydraulic system. Download our latest hydraulic hose dash size chart now and make informed decisions for your projects.
