Heat Buildup in Thin Wall Drilling and How to Reduce It
Heat buildup in thin wall drilling is a problem that affects both the process and the part quality. The thin wall cannot conduct heat away from the cutting zone as fast as a solid section can. The heat accumulates locally, causing thermal expansion that changes the bore diameter during the cut and leaves residual stress in the part afterward. Problem Description When heat accumulates in a thin wall section, the material expands at the cutting zone. The bore diameter temporarily shrinks as the expanded material pushes inward. The drill then cuts a larger diameter than intended because it is cutting into the expanded material. When the part cools, the bore spring back undersize or out of round. ...