Downward Mount Ball Transfer Unit SI-51
The SI-51 is a downward mount ball transfer unit with a 51 mm diameter steel ball, rated for 600 kg working load and 700 kg maximum load. It is mounted through a flange with a 102 mm diameter base, allowing heavy flat or smooth objects like trays to be moved and rotated in any direction by hand. The unit weighs 6.4 kg and is available with a steel, galvanized steel, chrome-plated steel, or stainless steel case.
Product Overview
The SI-51 is a downward mount ball transfer unit with a 51 mm diameter steel ball, rated for 600 kg working load and 700 kg maximum load. It is mounted through a flange with a 102 mm diameter base, allowing heavy flat or smooth objects like trays to be moved and rotated in any direction by hand. The unit weighs 6.4 kg and is available with a steel, galvanized steel, chrome-plated steel, or stainless steel case.
Part of the SI SD Series range, used in Warehouse and Distribution Centres.
Key Benefits
- Carries 600 kg per unit in normal service and 700 kg at peak load
- Downward mount with flange base allows secure attachment to a deck plate
- 51 mm diameter steel ball provides stable rolling under heavy static and dynamic loads
- Steel, galvanized steel, chrome-plated steel or stainless steel case options for different environmental conditions
- Two screw holes in the bearing surround allow firm attachment to worktables or benches
Application Scenarios
- Transfer points between two conveyor lines running at right angles in a high-load material handling system
- Loading and unloading stations for heavy trays or flat components in packaging or assembly lines
- Workbenches in processing machinery where large flat parts must be repositioned by hand
- Feeding systems for industrial presses or cutting machines requiring precise manual alignment
- Curved work surfaces on band saws or router tables where omnidirectional movement is needed
Who It Is For
- Conveyor system integrators building high-load transfer points
- Industrial equipment builders requiring robust ball transfer units for heavy-duty workbenches
- Assembly line designers needing manual repositioning of large flat components
- Material handling equipment makers integrating ball transfer units into processing stations
- Industrial distributors stocking ball transfer units by load rating and mounting style
Problems It Solves
- Heavy flat loads that cannot be moved easily across fixed deck plates or standard rollers
- Transfer points where product must change direction without powered diverters
- Manual repositioning of large trays or components that require omnidirectional movement
- Workbenches where a single unit must support high static and impact loads without binding
- Systems requiring reliable attachment points for ball transfer units that can be serviced or replaced
Technical Features
- 51 mm diameter steel ball for high load capacity and durability
- Downward mount flange with 102 mm diameter base for secure bolt-down installation
- Steel case with optional galvanization, chrome plating or stainless steel for corrosion resistance
- Two screw holes in the bearing surround for solid attachment to worktables
- Overall dimensions of 127 mm diameter by 98 mm height for space planning and deck layout
Materials
- Carbon steel ball and case for general industrial use
- Galvanized steel case for improved corrosion resistance in damp environments
- Chrome-plated steel case for enhanced wear resistance and appearance
- Stainless steel case (SUS304) for wet, washdown or corrosive areas
Quality Control
- Load capacity verified against the 600 kg working load rating before packing
- Ball rotation checked by hand for free movement in all directions
- Material grade confirmed against the case and ball option ordered
Customization Options
- Case material selected between steel, galvanized steel, chrome-plated steel, and stainless steel
- Ball material is steel, as specified; no other ball materials are available for this model
- Other SI SD Series models available for different load ratings or mounting styles
Use Guide
- Divide the total load by the number of units in contact to ensure each unit stays under the 600 kg working load
- Keep peak and impact loading below the 700 kg maximum load figure
- Mount the unit on a flat, rigid deck plate so all balls sit at the same height
- Use the stainless steel case where the unit is exposed to washdown or corrosive conditions
- Avoid using on uneven or soft-bottomed items such as cloth-wrapped loads
Specifications
| Model No | SI-51 |
|---|---|
| Mounting | Downward mount |
| Load Capacity | 600 kg |
| Max Load Capacity | 700 kg |
| Weight | 6.4 kg |
| Ball Diameter | 51 mm |
| Mount Diameter | 102 mm |
| Case Material | Steel, galvanized steel, chrome-plated steel, stainless steel |
| Ball Material | Steel |
| Dimension | 127 x 98 mm |
Manufacturing Process
Step 1
Machining of the flange base and case body
Step 2
Assembly of the 51 mm steel ball and bearing support
Step 3
Drilling and finishing of mounting holes in the flange
Step 4
Final load check and packaging
Compared With Other Options
| Flange mount ball transfer units | Downward mount is bolted from below, allowing access to the mounting side, while a flange mount is bolted from above and may require deck plate modification |
|---|---|
| Lower rated SI Series units | The SI-51 suits 600 kg loads, so lighter applications are better served by a smaller unit with lower rolling resistance |
| Standard conveyor rollers | Ball transfer units allow movement in any direction, while rollers only move product along one axis |
Downward Mount Ball Transfer Unit SI-51 Questions
What load can one SI-51 ball transfer unit carry?
The rated load capacity is 600 kg per unit and the maximum load capacity is 700 kg.
How is the SI-51 mounted?
It is a downward mount unit, so it is bolted through the flange from below the deck plate.
Which case material should I choose?
Steel for general use, galvanized steel for damp environments, chrome-plated steel for wear resistance, and stainless steel (SUS304) for washdown or corrosive areas.
Is a stainless steel version available?
Yes, the case can be supplied in stainless steel (SUS304).
How much does the unit weigh?
Each SI-51 weighs 6.4 kg, which is used for deck load and shipping calculations.
Can I get other load ratings in the same series?
Yes, the SI SD Series includes other load ratings, so ask for the model that matches your load per unit.
Get a Price for Downward Mount Ball Transfer Unit SI-51
Send the quantity and any material or surface option you need, and a quotation comes back against this model number.