Moly-Cop’s history dates back to early last century when both Armco (USA) and Comsteel (Australia) independently began to develop what it is now clearly recognised as industry leading grinding media products.


Back in the 1920’s the plant manager of a local cement company approached the Sheffield Steel Works in Kansas City in regards to using punchings from the bolt and nut shop as grinding media for grinding cement clinker.  From that humble beginning grew collaborations between engineers at Sheffield and forging equipment manufacturers to develop the first automated ball forging equipment.

In the 1930’s, Armco’s Sheffield Steel business of Kansas City produced the first heat-treated grinding ball alloyed with molybdenum and copper.  The new ball significantly improved wear performance versus the quality levels of that time and was patented and appropriately trademarked as Moly-Cop®.  In 1961, Armco built its first grinding ball forging operation outside the USA – now known as Moly-Cop Chile. This began several decades of growth resulting in an international Moly-Cop business with grinding ball plants located strategically around the world, including Chile, Peru, Mexico, and Canada.  In 2002, these operations became part of Anglo American's Scaw Metals (South Africa).


Construction and opening ceremony of the first grinding ball plant to be constructed in Chile, in Talcahuano

Moly-Cop's Australian operations, began with The Commonwealth Steel Company (Comsteel), which established its original facility on the Waratah site in Newcastle Australia in 1917.  The facility originally manufactured parts for the rail industry such as wheels, axles and other rail gear.  During the Second World War, the facility produced over 200,000 shells and other munitions, along with over 2 million steel helmets for the Allied soldiers.  The original Kansas City ball plant restarted as an independent company in 2003 and was acquired by OneSteel in 2007.


In January 2011, under now ARRIUM ownership (formerly OneSteel), all of our grinding media manufacturing facilities merged into a common Moly-Cop organisation, so creating the largest global grinding media company.

In 2017 and now under the ownership of American Industrial Partners, Moly-Cop comprises 10 ball manufacturing facilities spread across the globe, utilizing the best available technologies, strategically located to efficiently supply all major global mining regions with a strong commitment to social and environmental responsibility.

Moly-Cop understands the expanding global demand for grinding media over the next 5 years, and we are focused on expanding our current capacities to serve the increasing demand being generated by a diverse range of mining operations worldwide.  This, combined with the strategic location of our facilities in key mining markets, provides security of supply to our customers.  Moly-Cop has recently expanded its operations in Kamloops, Canada in addition to the construction of a new greenfield facility in La Joya, located in the south of Peru.


Moly-Cop's latest grinding media plant located in La Joya, southern Peru


Moly-Cop's has doubled capacity in Canada with the addition of a new grinding ball facility on the existing site