Method and apparatus for hard machining orifices in fuel system and engine components

A heat-treated fuel system component comprising:

• a heat-treated body;
• and
• at least one orifice hard machined into the heat-treated body based on a desired flow rate of the at least one orifice,
• wherein the at least one orifice comprises a first orifice, the first orifice having a first portion and a second portion,
• wherein the first portion is hard machined into the heat-treated body to a finish flat;
• wherein the second portion is hard machined through the heat-treated body from the finish flat of the first portion to an exterior of the body such that a corner is formed between the finish flat of the first portion and the second portion,
• wherein a diameter of the second portion is smaller than a diameter of the first portion, and
• wherein the corner between the first portion and the second portion is formed so that an edge condition exists between the finish flat of the first portion and the second portion of the first orifice having a dimension of 100 microns or less.

A machining system comprising:

• a component fixture configured to mount a heat-treated blank of a heat-treated fuel system component;
• and
• a machine tool configured to:
• form a first portion of an orifice to a finish flat in the heat-treated blank of the heat-treated fuel system component, and
• form, at an end of the first portion, a second portion of the orifice to an exterior of the heat-treated blank of the heat-treated fuel system component so that a corner is formed between the finish flat of the first portion and the second portion, wherein a diameter of the second portion is smaller than a diameter of the first portion;
• and
• the corner being formed so that an edge condition exists between the finish flat of the first portion and the second portion of the first orifice having a dimension of 50 microns or less.