Rolling Mill Know-How: Choose the Right One for You!

Bonny Doon pattern plate in a rolling mill; note the gorgeous texture of the metal as it comes out from between the rollers!

After completing my MFA, I set up a small studio to begin work. Very quickly, I found that I had overlooked one tool that stood out as a “must-have” in my studio: a rolling mill. A rolling mill is one of the most useful tools to have whether you will be rolling out sheet or wire or making material in a pinch to use in current projects. Rolling mills are also a great way to uniquely texture and pattern your pieces. Using pattern plates, such as those made by Bonny Doon Press & Tooling—or creating your own patterning tools—creates countless opportunities to personalize your work.

Rolling mills have a simple and basic construction. When you choose a rolling mill, it’s important to understand the terminology and, most importantly, to determine what you want your rolling mill to do. Terms such as “gear ratio,” “gearbox,” and “gear reduction” all can sound daunting, but they are terms used to describe the basic function of your mill. The gearbox holds the gears that reduce the amount of force it takes you to turn the rollers one time around. In a gear-reduction rolling mill, a gear ratio is typically given 7:1, 6:1, 5:1, 4:1 and so on.

This simply means that, with a rolling mill that has a 5:1 gear ratio, you will rotate the handle five complete turns in order for the rollers to complete a single rotation. Why would you want to turn the handle five times just for the roller to turn once? Well, it seems like more work, but, by turning the handle more times, you are using less physical strength and allowing the gears to do the work. Direct drive mills only require you to turn the handle once and the rollers will turn one complete rotation; however, this requires more strength and can lead to fatigue if you are rolling larger pieces. Direct drive rolling mills may also cause dips or imperfections in the pattern if your turn is not smooth and complete. There are also electric mills available that will do all the work for you, no cranking necessary!

Left to right: Durston hand-powered rolling mill; Durston electric rolling mill

The steel used to manufacture the mill is also very important. Choose a rolling mill made with a good, high-quality hardened steel—this helps ensure that the mill can not only produce crisp, even forms but will also have a long and profitable service life worthy of your investment in it. Durston rolling mills are among the best on the market, created from hardened steel and highly unlikely to dent, crack, or become damaged.

Some rolling mills are simply equipped with a smooth, flat roller while others have a combination roller. The combination roller offers a section of flat surface and a section with wire grooves. The wire grooves do not roll perfectly round wire, though; for that, you would need a full round rolling mill. The wire grooves roll mainly square wire. Extension rollers are also an addition that a rolling mill may have; extension rollers are rollers that extend out to the side of the rolling mill. These typically allow you to roll half round wire or D-shaped grooves. There are other shapes available, too, based on your design needs.

When deciding which rolling mill to purchase, think about the work you want to accomplish using the rolling mill. Determine if the grooves or extension rollers are important for your process or not. It can save you money and also can extend your flat roller space allowing you to roll larger dimensions of metal. Whether you are rolling scrap metal, ingots, and wire, or patterning flat sheet you’ll find the mill you need at Rio. Give our Tech Team a call and we will be happy to help you find the rolling mill that’s just right for you!

Visit our website to see all of our rolling mills and click on the “Articles and Videos” tab to find information, videos, and projects featuring the use of these “must-have” machines!