The size of the carbide on the tip of the tool can impact horsepower and production of the milling machine, as well, Munks points out. "Smaller horsepower machines generally need a sharper, smaller carbide tip on the cutter tool for better penetration, and it will reduce vibration," he explains. "Good penetration of the material being milled is a key factor in getting the most production out of any machine."
Use the right tools
"Cutting teeth are the No. 1 operating cost for a milling machine, so any improvements in consumption can be the difference between success and failure," says Baker. "Part of the equation is to match the two main components of the tooth - carbide and steel - to the application."
Premature failure is normally due to using the incorrect tool type, horsepower per tool impact rating and/or carbide and base structure for the material conditions, says Taraschi. "The life of a tool depends on having the correct tool matching unit horsepower to material conditions," he emphasizes.
"Today, a milling contractor might have as many as five different tooth models in his inventory to address every application in his portfolio," adds Wiley.
Taking the time to speak with tool manufacturers to ensure a good match (unit horsepower to regional material) will result in better production and longer tool life. "If you opt to install inadequate tools per unit horsepower to material, the results will be more costly due to frequent tool replacement and longer unit downtime," says Taraschi.
A tool that's too small for the application or machine won't last long. "A tool too big for a low-horsepower machine slows down the machine," says Chudowski. "The life of the tool might be extended, but the efficiency of the machine is unacceptable (not economical)."
That said, there are times when a faster and smaller tool may be better to improve the overall efficiency of the total operation - for example, when the paving operation is directly behind the milling operation.
Material density also plays a role in tool selection. "If you are going to be cutting a looser material, you might need more steel to prevent the loose material from washing out the steel before the carbide is used," says Baker. "If you are cutting harder material, such as concrete, you would probably want more carbide, since there will be more impact wear."
Another part of the equation is tooth shape or geometry. "Some teeth have a steeper slope for more penetration, while others are more blunt," says Baker. "Proper selection is dependent on the type of material to be cut. The best way to find out which is best is with experience, but the tool manufacturers also have a lot of expertise they can provide to help in the selection."