THROUGH MIST SUPPLY METHOD FOR TOOL, AND DEVICE

PROBLEM TO BE SOLVED: To provide a through mist supply method for a tool and a device capable of supplying an oil mist having a uniform particle size in a stable state, capable of keeping the density of an oil mist grain included in air constant, and causing no accumulation of crude oil in piping. SOLUTION: This method blows out the oil mist from a tool tip via a mist hole bored in the tool by forcibly feeding the mist to a mist supply hole communicating with a tool installing hole of a tool holder from an outflow port by turning oil into the mist by pressure air supplied to an inflow port of a mist generator. The tool holder is provided with a separating means for separating the oil mist forcibly fed from the mist supply hole into a through passage opening on the tool tip and a bypass passage arranged in the tool holder and opening in an external part by passing through the mist hole, and a bypass passage resistance adjusting means for adjusting the passage resistance of the bypass passage according to the passage resistance of the mist hole of the tool so that a pressure difference between the inflow and outflow ports of the mist generator becomes constant.