Rough Bore heads have a twin-bore configuration and are used for rough boring holes. They are capable of removing up to 10% of the final bore diameter. The heads come in 5 sizes but they all share the same characteristics. They use two cartridges that each hold a carbide insert. Each cartridge can be individually adjusted. They should be adjusted to the same diameter, producing a “two-flute” boring tool. Symmetrical adjustment of the two cartridges produces the best concentricity.
Drilled holes or holes produced by other means such as end milling may lack the precise location required of tight tolerance holes. In such cases, it is beneficial to use a rough boring head to produce bored holes that are spot-on location and leave a consistent amount of stock for the fine or finish boring head to produce high-tolerance bores with very accurate location, near-perfect roundness, and excellent surface finish.
Chip control is key in rough boring applications, especially when boring blind holes. If there is no place for the chips to evacuate the bore, it is extremely important that the chips are broken and flushed out of the bore. All Haas boring heads are equipped with holes for through-tool coolant. If your machine is equipped with a through spindle coolant option, use it!