Ball roller BUSM 25

Ball tables for workshop goods are often built on ball rollers with a threaded stud, and BUSM 25 is the heavier version of that design: a 25 mm steel ball in a housing with an M8 stud that is screwed straight into a threaded hole or locked with a nut through a sheet. No punching tool and no cut out with tight tolerances; you drill, tap and screw.

The dynamic load capacity is 45 kg at 4 km/h. Spread over the three or more balls the goods should always rest on, that gives work surfaces that handle tool boxes, machine parts and filled plastic crates with a good margin. The rule of thumb about three carrying balls is not only about capacity but just as much about the movement; with fewer contact points the goods tip between the balls and slide jerkily.

Compared with the smaller ball rollers with an M6 stud the step up is marked, both in ball size and in capacity. If you are choosing between the sizes: take the larger one if the goods are mixed or if the table is to last a long time. An oversized ball only rolls more easily, while an undersized one becomes a wear part.

Data from the manufacturer's sheet: ball diameter 25 mm, threaded stud M8 x 25, overall height 36 mm and outer diameter 31 mm. The net weight is 0.12 kg. The temperature range runs from -30 °C to +70 °C, which covers heated as well as unheated industrial buildings and chilled spaces; hotter processes call for other versions.

The overall height of 36 mm is worth noting. It gives room for a nut and washer under the board and at the same time lifts the ball a little above the surface, which is practical when the goods have ledges or unevenness on the underside that would otherwise catch the table. In return the design builds higher than with drop in units, so calculate the total height before you lock the working height.

Typical applications in Swedish industry: turning stations at manual assembly, infeed tables to press brakes and saws where the blank is lined up before machining, picking stations where crates are spun toward the operator and fixtures and rigs in machine builds. We also see it in packaging lines where filled cartons are turned before sealing. The M8 stud also fits threaded slot nuts for aluminum profiles, a quick way to build rolling support into a profile structure without extra mounting plates.

You choose the spacing between the balls by the smallest base dimensions of the goods, so three balls always carry wherever the load ends up. The base of the goods also matters; a flat and stiff base rolls easily, while soft or damaged bases increase the resistance and wear on the balls. If the goods are mixed, size for the smallest and softest item.

Gravity ball tables are also cheap to run. No motors, no sensors and no controls; the only thing that moves is the ball, and the only thing the surroundings have to contribute is an operator and a reasonably level floor. For flows at a low rate that is often exactly the right level of ambition for a work station.

Care is simple: keep the ball free from chips and granulate, blow it clean when needed and replace units that start to stick. With stud mounting the change takes less than a minute, which makes it reasonable to see the ball rollers as consumable parts in a dirty environment rather than components to be reconditioned.

Not sure whether the M8 stud suits your design, or whether you should choose drop in mounting instead? Call us and we will sort it out.