Split & Bolted Rolls
Split and Bolted construction is used primarily on driven stand rolls. In this type of roll construction the roll is constructed of interlocking hubed and counter bored segments that are assembled into a single roll body and bolted securely together. The seams are most often centered at the low points of the contour or "throat" of the roll. To renew a worn contour we simply unbolt the roll segments, remove material from the inner faces, re-bolt the pieces together, and re-machine the narrowed contour to the original root diameter. The roll body when originally produced was made wide enough to allow multiple regrinds.
Thus, the roll's overall diameter, and therefore it's working surface area, is never reduced. It will always set up and perform like a new roll. This construction is more costly to produce and regrind but the goal is to expedite mill set up times. The set up benefits of using split and bolted tooling are best realized when this concept is implemented on all of the tooling for a given mill. Ask a JMC Rolls representative about the pros and cons of using Split and Bolted tooling in your operations.
Some Benefits of Split and Bolted rolls are:
- Consistent forming and drive characteristics throughout the life of the tooling
- Consistent roll wear throughout the life of the tooling
- Reduced mill set up times
- Reduced incidence of operator error
Some Considerations when buying Split and Bolted rolls are:
- Because the roll width is reduced at regrind new shaft spacers must be included in cost
- Increased initial tooling costs
- Increased regrind costs
