Steel is the most common metal used in industry, from construction, fabrication and many more. Did you know that iron is the 4th most common element in the Earth’s crust? But even though making and working with steel is so common, there is the potentially tedious process of removing mill scale. Mill scale is the dark, flaky coating that forms on the surface of steel during the manufacturing process. However, with the right abrasives you can effectively remove this coating and achieve a clean, smooth finish.
There are many different methods for removing mill scale such as pickling or electro-chemical descaling. These methods are expensive, complicated and dangerous. Abrasives offer an easy way to remove mill scale. Although there are many different methods to removing mill scale we believe the best way is using our range of clean & strip discs and wheels. It is a huge timesaver especially when paired with a variable speed grinder such as the Varilex WSF 1800. Due to the open elastic fabric pores of the CLEAN material, the products do not clog and achieve a sandblasting effect on metal surfaces. We will talk about other methods below:
Fibre Discs; these discs are low cost and come in a variety of grits and type of abrasive. Generally, most would use a grit 36 ceramic for this application and will remove the mill scale quickly however the discs do not last as long and leaves deep grinding marks in the surface. Some discs also come with the added benefit of cooling additives to prevent warping like the Cold Steel Ceramic discs. For more information on our fibre discs, click here.
Flap Discs; flap discs are a very common method to remove mill scale, especially before welding. These discs are available in a variety of grits and types of abrasive. Grit 40 is common for this application and ceramic abrasive is recommended, for example the TRIMFIX Hellfire. Please click here.
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Wire wheels: using wire brushes or wire wheels are good to deal with mill scale on intricate shapes. However, if the mill scale is heavy wire brushes would be a slow option with many passes required. Our wire wheels come either as brass coated or stainless steel. To view our wire wheels please click here.
Clean & Strip discs/wheels are a very efficient and cost-effective way to remove mill scale, provided you have a good variable speed machine. Running these discs too fast significantly reduces their lifespan. These discs do not clog and have silicon carbide abrasive which leaves the metal underneath virtually untouched like a sandblasting effect. We recommend these types of discs to deal with mill scale and they come with either a hook and loop backing, wheels or with an M14 thread. To find out more about our M14 Magnum Clean+ Discs, please click here.
Gum wheels are fantastic at removing heavy carbon build up and mill scale, leaving a decorative, clean finish. These unique wheels are rubberised making them conform better to the surface and can even be run on curved surfaces. These wheels are used with our POLY PTX 800 machine. To learn more about gum wheels click here.
Removing mill scale is essential to achieve a clean and smooth finish for an effective weld. By choosing the right abrasives you can effectively tackle mill scale removal and restore the steel surface to the desired state. Ready for further treatment or finishing.
Depending on the workpiece you need to remove scale on and which abrasive is used. For example the POLY PTX Gum Wheel would require the use of the POLY PTX machine while the MAGNUM Clean+ would use the Varilex 1800 machine.
Did you know that 30 years ago we were one of the first to develop methods to use clean and strip discs on their face side instead of only on the side of the disc.
