By drilling with a bit, why is the hole drilled straight 2 larger than the diameter of the drill?
Equipment: drill precision, bearing wear and drill card precision drill conical burr speed selectionThe lateral and lateral deflection of the bit and the size of the back angleDrilling can only be used for fastening, for mating, for boring, for reaming
The drilling depth - to determine the guiding edge and drilling parameters of the drill: shallow ordinary drill, a set of parameters, if more than 10 long deep hole diameter ratio, cooling the drill bit will choose to guide blade, and soon after the first slow step feed, with 2 sets of parameters, the other through hole, then reduce the parameters in the proposal through;
Hardness of the machined material --- determine the size of the drill point: cast iron is used at 135 degrees - 140 degrees; aluminum alloy is about 120 degrees;
Drill bit, drill out of the hole than the drill diameter, because drilling cuttings will increase the extrusion aperture; at the same time, for the convenience of a chip it is necessary to improve bit will increase; if the concentricity is not good, it will increase more.
