All photos courtesy of PRAB Inc.

How effectively a metalworking company manages its cutting tools can impact profit margins. Cutting tools can account for 3% to 5% of total manufacturing cost, and metalworking facilities lose money when cutting tools are purchased earlier than necessary. Tools purchased but not yet put into operation is money locked up in tooling inventory instead of earning a return on investment.

Metalworking facilities that maximize tool life are more profitable. One of the secrets to tool longevity is maintaining best practices for coolant management.

Coolant connection

Coolant purity plays a major role in tool life. By preventing tools from exceeding critical temperatures during cutting, coolant performs a pivotal function in machining. However, cutting fluids deteriorate as they become contaminated with tramp oils, metal fines, and bacteria. Once coolant deteriorates to the point that coolant lubricity becomes ineffective, tools dull prematurely, break during the first cut, and fail to meet surface finish and part size tolerances.

Further, as coolant breaks down, it damages machine tools, pumps, sumps, and electronic components. Machine parts and interiors become vulnerable to rust and corrosion, equipment surfaces suffer from abrasion, and tramp oil mist causes mechanical failures and prematurely clogs air filters.

Coolant recycling

Continuously monitoring coolant to maintain the manufacturer’s recommended concentration level is the most important parameter for long tool and coolant life. However, testing, adjusting concentration levels, and treating contaminated coolant with biocides requires time and attention.

Coolant recycling equipment automates coolant quality management by separating solids from liquids and removing free-floating and mechanically dispersed contaminants, including tramp oils and bacteria. These systems also automatically adjust fluid concentration for fluid recovery.

Clean, recycled coolant reduces sump maintenance, improves machining quality, and prolongs tool life up to 25%, according to case studies. And, advantages extend beyond tools. Coolant filtration and recycling systems significantly reduce new fluid purchase costs and lower hazardous waste disposal costs. These systems extend coolant 2x to 5x. Automated systems also eliminate unfortunate byproducts of dirty coolant such as foul odors and dermatitis.

Keeping coolant clean through automated coolant recycling systems has been shown to extend tool life by up to 25%.


Back-end equipment solutions enable manufacturers to take control of coolant management and maximize equipment service life. Managers sometimes reject back-end investments because of initial equipment acquisition costs or because back-end equipment doesn’t directly expand production capabilities. However, shop managers should note that a proactive approach to operational improvements will help reduce financial strains during challenging market conditions. Investing in capital equipment that lowers costs sets the foundation for a more sustainable growth strategy in the long term.


About the author: Mike Hook is sales & marketing director at PRAB, maker of engineered conveyors and equipment for processing turnings, chips, and metalworking fluids. He can be reached at