To crimp hydraulic hose fittings, identify a validated hose and fitting combination, cut and clean the hose, mark the specified insertion depth, seat the fitting fully, and crimp it with the approved dies and machine settings. Then measure the finished crimp diameter and inspect the assembly before releasing it for use.
The correct result depends on the complete assembly system: hose, fitting, ferrule where applicable, crimper, tooling, and current crimp specification. Matching the hose diameter alone is not enough. This guide explains the process, how to read a hydraulic hose crimp chart, and what to check when a hose leaks at the crimp.
What Is Hydraulic Hose Crimping
Hydraulic hose crimping permanently secures a fitting to a hose by compressing a metal shell or ferrule around the hose and fitting stem. Segmented dies close around the shell to produce the geometry specified for that component combination.
Crimp fittings differ from field attachable fittings, which use a different assembly method. For help identifying connection styles, see our guide to hydraulic fitting types.
Tools and Specifications You Need
Prepare the following before cutting the hose:
- New hose and fitting components approved for use together.
- The current crimp specification for the exact hose series, size, fitting, and ferrule.
- A hydraulic hose crimping machine with compatible tooling and sufficient capacity.
- The specified hydraulic hose crimping dies, adapters, and locating accessories.
- A suitable hose cutting machine, measuring tape, and marking tool.
- Calibrated calipers or the measuring instrument required by the crimp specification.
- Appropriate cleaning equipment and protective caps or plugs.
- Skiving equipment and assembly lubricant only when the component instructions require them.
Use eye protection and any additional protection required by the cutting and crimping equipment. Keep hands clear of the closing dies. If replacing an installed assembly, isolate the equipment and release stored pressure before removal.
How to Read a Hydraulic Hose Crimp Chart
A hydraulic hose crimp chart connects a specific component combination to its assembly requirements. Use the latest data issued or approved by the supplier responsible for that combination.
| Chart field | What to check |
| Hose identification | Exact hose series and nominal size, including the relevant construction |
| Fitting identification | Stem or fitting series and part number |
| Ferrule identification | Correct shell or ferrule part number when supplied separately |
| Preparation | Skive or no skive requirements and specified preparation length |
| Insertion depth | Distance used to mark and confirm full fitting insertion |
| Tooling | Die identification and any required adapters or positioning tools |
| Crimp requirement | Finished crimp diameter, tolerance, and any specified crimp length |
| Machine information | Applicable crimper model and its setup instructions |
Hose inside diameter, die identification, machine setting, and finished crimp diameter are different values. A setting copied from another crimper may not produce the required diameter. Likewise, a chart for another fitting series cannot validate your assembly.
How to Crimp Hydraulic Hose Fittings
Step 1 Confirm the Hose and Fitting Combination
Check the application pressure, fluid, temperature, hose size, and end connections. Then confirm that the selected hose, stem, and ferrule are an approved combination. Similar appearance or matching nominal size does not establish compatibility.
Inspect the new components for damage and contamination. Confirm that the crimp chart matches their part numbers. If you cannot identify the components or obtain the correct data, resolve that before assembly.
Step 2 Measure the Required Assembly Length
Establish the finished assembly length and its measurement reference points from the drawing or order. Account for the length contributed by both fittings when determining the hose cut length.
Check routing, movement, and minimum bend radius. When using two angled fittings, confirm their required orientation before crimping. Our guide to measuring hydraulic hose explains the dimensions to record.
Step 3 Cut and Clean the Hose
Cut the hose squarely with equipment suitable for its construction. Inspect the cut end for distortion, loose reinforcement, and damage to the inner tube. Correct an unacceptable cut before fitting insertion.
Remove cutting debris using the cleaning method specified for the hose and system. Prevent dirt from entering the open ends during the remaining work. See how to cut hydraulic hose for preparation guidance.
Step 4 Prepare the Hose End and Mark Insertion Depth
Skive the hose only if the selected fitting system requires it. Follow the specified preparation length and method. Removing material from a no skive hose assembly can damage the intended fit.
Mark the specified insertion depth clearly on the hose cover. This mark shows whether the fitting has reached its required position and helps reveal movement during crimping. Insertion depth and crimp length describe different dimensions.
For preparation differences, read our skive versus no skive hydraulic hose guide.
Step 5 Insert the Fitting Fully
Assemble separate ferrules and stems in the sequence required by their instructions. Push the hose into or onto the fitting until it reaches the specified position, and check the insertion mark.
Use lubricant only where the component manufacturer permits it, and use the specified type. Some systems have restrictions on hose lubrication. Do not apply a general instruction to oil every hose and fitting.
Step 6 Set Up and Operate the Hydraulic Hose Crimper
Select the die set and accessories from the approved crimp data. Check their condition, cleanliness, and correct installation. Confirm the crimper’s calibration or verification status according to its operating instructions.
Position the fitting at the specified location in the dies. Check any elbow orientation and keep the hose supported without pulling the fitting away from its insertion mark. Run the crimping cycle according to the machine instructions, then open the dies and remove the assembly.
Crimping force or pump pressure alone does not confirm a correct crimp. The finished assembly must meet its dimensional requirements.
Step 7 Measure and Inspect the Finished Crimp
Measure the crimp diameter at the location and in the directions specified by the component manufacturer. Where the instructions require measurements across the flats, keep the measuring jaws clear of die ridges and raised markings. Some systems require additional measurements to check taper or variation.
Compare the results with the specified tolerance. Also check that the insertion mark remains correctly positioned and inspect for cracks, displaced components, damaged hose, or other defects.
Hold an assembly that fails inspection. Check the data, tooling, setup, and calibration before making another assembly. Any adjustment or rework must follow the manufacturer’s instructions; an extra crimp is not an automatic remedy.
Step 8 Complete Final Checks and Identification
Confirm finished length and fitting orientation, complete the required cleaning, and protect the ends. Record the component identities and inspection results as required by the job.Perform any specified proof or acceptance test under an approved procedure using suitable guarded equipment. Obtain the test pressure, duration, and acceptance criteria from the applicable specification. A visual inspection or an arbitrary test pressure cannot establish the assembly’s pressure rating.
Choosing Hydraulic Hose Crimping Dies and Machines
Select dies by the approved assembly data and crimper compatibility. Die numbers and colour codes are specific to their tooling systems, so a matching number on another manufacturer’s die does not establish an equivalent tool.
A portable crimper can suit field work, while a workshop machine may suit larger sizes or higher production volumes. Check approved tooling availability, fitting clearance, capacity, power supply, and access for inspection. The machine still needs to produce the specified result for the chosen hose and fitting system.
For equipment options, see our hydraulic hose crimping machines.
Why Is a Hydraulic Hose Leaking at the Crimp
If a hydraulic hose leaks at the crimp, stop the equipment and isolate and depressurize the system before inspection. Keep hands away from suspected pressurized leaks. First establish whether fluid originates at the hose attachment, the threaded connection, or another nearby component.
| Finding | Possible cause to investigate | What to check next |
| Fluid at the hose and ferrule interface | Incorrect crimp dimensions, incompatible components, or damaged inner tube | Part numbers, approved crimp data, measured dimensions, and hose condition |
| Insertion mark has moved away from its required position | Incomplete insertion or fitting movement | Marking method, specified insertion depth, and assembly handling |
| Cracked or distorted ferrule | Wrong tooling, incorrect positioning, or excessive compression | Die identity, positioning instructions, and measured crimp dimensions |
| Leakage develops during operation | Pressure peaks, temperature exposure, vibration, or bending stress | Application conditions and hose routing as well as the assembly record |
| Fluid at the thread or sealing face | Connection or seal problem outside the crimp | Connection type, sealing surfaces, seal condition, and assembly instructions |
These findings guide an investigation; they do not establish the cause on their own. Replace a defective assembly as required and correct the underlying problem. Avoid tightening the ferrule, adding a clamp, or applying sealant around the crimp as a repair.
For a wider diagnosis, see hydraulic hose leaking at the fitting.
FAQs of Hydraulic Hose Crimping
Can You Crimp Hydraulic Hose Fittings at Home?
The location does not determine assembly quality. You need the correct components, approved crimp data, suitable equipment, inspection tools, and the knowledge to use them. If those are unavailable, have a qualified hose assembly provider make the hose.
Can You Crimp a Hydraulic Hose Without a Crimper?
A permanent crimp fitting requires the specified crimping equipment. A vice, hammer, or ordinary clamp cannot reproduce that assembly process. Field attachable fittings are a separate design and must be approved for the selected hose and application.
Is There a Universal Hydraulic Hose Crimp Size Chart?
There is no universal chart covering all hose and fitting combinations. Even assemblies with the same nominal hose size can require different ferrules, dies, finished diameters, and tolerances. Use current data for the exact combination.
Can You Reuse a Crimped Hydraulic Fitting?
Treat permanent crimp fittings as single use unless the manufacturer explicitly provides a validated reuse procedure. Field attachable fittings have separate reuse rules. Do not assume that a fitting removed from an old assembly is suitable for a new hose.
Should Every Hose Be Lubricated Before Insertion?
Follow the fitting system’s instructions. Lubricant type and whether lubrication is permitted depend on the components. An insertion problem may also indicate incorrect parts or preparation, so do not force an unidentified combination together.
Get Help Specifying Your Hose Assembly
Send Kingdaflex the hose series and size, application pressure, fluid, operating temperature, finished length, and fitting requirements. Include a drawing or clear component identification when available.
Contact Kingdaflex to discuss component selection or a completed custom hydraulic hose assembly.
