Cause: Cutting Conditions

Solution: Check for excessive speed and feed - See chart.

 Cause: Tool

Solution: Select a coated tool.

 Cause: Part

Solution: Make sure prior operation did not work harden the metal.

Cause: Tool

Solution: Select a coated tool.

Cause: Cutting Force

Solution: Check for excessive feed rate (IPR) - See chart.

Cause: Heat

Solution: Use the SCT coolant holder. If coolant is not available, use shop air and a coated tool.

Cause: Cutting Conditions

Solution: Check for excessive feed and speed and depth of cut - See chart.

Cause: Tool

Solution: Select a tool with a radius. A radius is stronger than a sharp corner.

Cause: Part

Solution: Check the drilled hole.

Cause: Cutting Conditions

Solution: Check for excessive feed rate (IPR) - See chart.

Cause: Built-Up Edge

Solution: See above (Built-Up Edge)

Cause: Set Up

Solution: Set tool above center. Reduce the overhang ratio. Clamping length should be at least 3x the boring bar diameter. Change the speed of the machine. Speed change may break up harmonics and reduce chatter.

Cause: Boring Bar

Solution: Select the largest diameter boring bar that will bore the required diameter.

Cause: Chip Packing

Solution: If the boring bar is too large to allow chips to evacuate, then the chips may pack on the tool and cause the bar to deflect away from the bore.

Cause: Program

Solution: If the taper is consistent, then the program can be altered to bore a taper in the opposite direction resulting in a straight hole.

Cause: Cutting Forces

Solution: Reduce forces. Deflecting bar below center causes hole to become larger.

Cause: Built-Up Edge

Solution: Built up edge will cause the hole to become larger until the built edge breaks off, then the hole becomes smaller.

Cause: Program

Solution: If taper is consistent, then the program can be altered to bore a taper in the opposite direction resulting in a straight hole.