The 450–530 mm range appears on specific HENLI MT model rows; it is not a universal range for every hydraulic decoiler. Buyers must confirm the actual contracted/expanded diameter, coil-core tolerance, load position and free-end support for the selected machine.
Which Models Use a 450–530 mm Reference?
The current standard MT table shows a 450–530 mm coil-ID reference. The current hydraulic model table lists 450–530 mm for some rows and 480–530 mm for others. Therefore, the article title is a specific selection topic—not permission to apply 450–530 mm to every hydraulic uncoiler.
| Source row | Current public ID reference | Use |
|---|---|---|
| Standard MT model table | 450–530 mm | Initial selection only; confirm exact model and options |
| Hydraulic MT-800 / MT-1000 | 450–530 mm | Use only with listed rows and approved configuration |
| Hydraulic MT-1300 / MT-1600 | 480–530 mm | Do not overwrite with the article’s 450–530 title |
| Custom mandrel | Project-specific | Requires drawing and coil-core confirmation |
How Does Hydraulic Expansion Move the Segments?
A hydraulic cylinder or actuator moves a wedge, sleeve or linkage that drives the mandrel segments radially. The coil is loaded with the mandrel contracted, aligned to the line and seated, then expanded within the approved range. The segment arc and coil core transfer load into the spindle.
What Can Cause Poor Mandrel Grip?
- Wrong coil ID
The bore is outside the contracted/expanded range or tolerance. - Damaged core
Out-of-round, collapsed or contaminated core prevents even seating. - Incomplete expansion
Hydraulic, linkage or segment travel is not reaching the approved position. - Incorrect loading position
The coil is not seated/aligned and creates an unfavorable load path. - Segment wear or obstruction
Sliding parts, wedges, pins or guides cannot move correctly. - Unsupported load
The selected shaft/support arrangement does not match coil width, weight or COG.
When Is an Outboard Support Arm Used?
An outboard support carries the free end of a cantilever mandrel when the approved design requires it. Selection cannot be reduced to one universal rule such as “always above 10 tons.” Engineering review should consider shaft geometry, bearing span, coil width/weight, center of gravity, loading method and dynamic duty.
| Device | Function | Not a substitute for |
|---|---|---|
| Hydraulic expansion | Adjusts the mandrel segments to the coil ID | Rated shaft/frame capacity |
| Outboard support | Supports the mandrel free end | Correct coil centering and seating |
| Press arm | Helps contain the coil outer wraps | Mandrel support or tension control |
| Side retainer | Helps limit axial movement | Repairing a telescoped coil |
| Coil car | Aligns/lifts the coil for loading | Approved mandrel range and load rating |
What Maintenance Checks Are Evidence-Based?
Inspect for leakage, hose/fitting damage, abnormal segment movement, looseness, wear, contamination, lubrication condition, transmission problems and abnormal noise/heat/vibration. Exact oil, pressure, torque, clearance, replacement threshold and daily/weekly/semiannual interval must come from the supplied model manual, BOM, component documentation and duty record.
| Area | Condition to observe | Required source before adjustment |
|---|---|---|
| Hydraulic actuator | Leakage, drift, damaged hose/fitting, abnormal motion | Hydraulic drawing and component manual |
| Segments/linkage | Uneven travel, obstruction, wear or looseness | Assembly drawing and permitted clearances |
| Shaft/bearings/support | Noise, heat, vibration, alignment or abnormal movement | Model manual and load/support configuration |
| Transmission/brake | Wear, slip, overrun or abnormal temperature | Drive/brake documentation |
| Fasteners/foundation | Movement, looseness or changed datum | Approved installation and torque data |
What Data Should Buyers Confirm?
Provide actual coil ID minimum/maximum and tolerance, core construction/condition, OD, weight, width, material strength/thickness, line speed/cycle, loading method and the need for hold-down, retaining or outboard support. A nominal 508 mm core alone is not enough.
Frequently Asked Questions
Does 450–530 mm mean the mandrel fits every 20-inch coil?
No. The actual core ID, tolerance, roundness and condition must fit the approved range and segment design.
Does hydraulic expansion increase the rated coil load?
Not by itself. Rated load depends on the complete shaft, bearing, frame, mandrel and support configuration.
How often should the mandrel be serviced?
Use the supplied model manual, component requirements, duty cycle and inspection history. A universal weekly or six-month interval is not valid for every machine.
Related HENLI Resources
Confirm Coil ID and Load Path Before Quotation
Send the actual coil bore/tolerance, OD, weight, width, material, speed/cycle and loading arrangement. HENLI can confirm whether a listed 450–530 mm row or a custom mandrel is appropriate.
