Whether you have a small, large or medium sized rolling mill for precious metal projects, find out the facts before getting to grips with rolling sheet metal. Use our guide below before using a rolling mill to ensure you are getting the most out of your jewellery making projects.
With our handy guide, discover tips and techniques on how to use a rolling mill machine to create beautiful jewellery, perfect for your latest precious metal projects.
How To Use A Jewellery Rolling Mill
Using A Rolling Mill – The Basics
Rolling mills are one of the more common jeweller’s tools seen in small and medium sized workshops. In essence, the rolling mill machine is a simple one that shares many traits with a mangle. The traditional jewellery rolling mill will have steel rollers; this means that when metal is passed between them it becomes compressed, changing the gauge or even shape of the piece. For example, changing a circle into an oval shape.
As a rough guide, when halving the thickness of sheet you will double the length (if rolling in one direction). Rolling sheet should be a gradual process, and the resulting compression of the metal will mean that the metal will work harder. Therefore in between each stage of rolling, the metal will need to be annealed.
In addition to rolling sheet, many of today’s rolling mill machines have the ability to roll wires into square or D shaped sections – this feature is ideal for creating a tapered or shaped effect.
Small rolling mills are the most practical for the small or home workshop with one pair of rollers. Larger and automatic mills are available for the larger workshop, but, like all rolling mills, they must be secured to a firm and steady surface – many manufacturers recommend a dedicated stand bolted to the floor.
Rolling sheet is a common and extremely useful feature which can be implemented by a jewellery rolling mill. First, ensure your sheet is prepared for rolling – this means that it should have been annealed, cleaned, and dried. Once this is ready, adjust the width of the rollers – many machines have a dial gauge to aid precise rolling gap measurement. As a physical test, try pushing the sheet between the rollers. If the sheet passes through, the rollers should be adjusted until it will not pass between them.
Once the rollers are in the correct position, the mill is ready to roll down the metal. The sheet should be supported in one hand, whilst the other turns the handle, thus drawing the sheet through the rollers. The sheet should be caught as it comes through, and its thickness checked using a vernier/calliper. Then, re-roll your sheet to achieve the required thickness.
Using A Rolling Mill To Create Ovals
To create an oval shape, take a silver disc and set the rollers as you would for rolling sheet and feed the disc through. Once the disc has been through the mill, check the thickness and length of the piece using a vernier or a calliper, and repeat the process as necessary. When feeding the oval through the rolling mill again, ensure that it is fed through the rollers in the same direction to ensure it elongates the oval.
Shaping Wire With A Rolling Mill Machine
Using a rolling mill with square grooves allows jewellers to shape (often into a square) and taper round wires. Before starting the process, the wire must be annealed, pickled and cleaned and dried thoroughly. The wire is then pushed between the square grooves and the handle turned so the wire is drawn into the grooved section of the rollers – this then shapes the wire. To ensure the required shape is achieved by using a rolling mill, turn the wire each time by 90 degrees.
How To Use A Rolling Mill To Form D Shape Wire
Rolling mills with D shape channels allow D shape wire to be formed, and follow similar principals as shaping. The wire is fed through the D shape section rollers and once the wire has passed through, the thickness can then be checked. If it is not of the required thickness, simply repeat the process.
Using A Rolling Mill: Best practice
When using a rolling mill, consider the following best practice hints & tips:
- Always use dry metal – any dampness will leave marks on the rollers and risk pitting.
- Roll metal gradually as too much pressure may result in the piece cracking when next annealing.
- Keep your rolling mill machine well maintained and oiled.
- Remove any marks on the rollers. Clean with a damp cloth and acetone to remove dirt. For more stubborn marks, carefully remove with fine wet and dry paper and fine steel wool.
- Keep the mill covered when not in use to protect the rollers from any workshop debris.
Rolling Mills are one of the more expensive jeweller’s tools, and although simple in nature, the mill can be put to many uses. When buying a rolling mill machine, like many tools, you should buy the best mill you can afford, with the better mills being more robust and having heavier and stronger rollers. For more information on jewellery rolling mills or to purchase your own, find everything you need from Cooksongold.