What is a twist drill made of?

Today, twist drills are made on computerized grinders

Go back pre computers - picture a horizontal mill/grinder with a wheel the thickness of the Flute spinning

The table of the mill is set so the the wheel sits at the angle of the flute, and the drill blank is in a rotary fixture on the table, so that when the table is moved (in what is called the X axis) the drill blank rotates at the appropriate rate

You lower the wheel a .001 or so, traverse the table, and repeat

• either between passes, or at the end, index the blank 180 degs to

do both flutes, OR in a production setting (aka you're a drill bit company), your grinder will actually have two wheels, with the wheels offset to the table, but the bit still rotates as the table traverses, so you gring BOTH sides of the bit at once