How are spade bits manufactured?
As spade bits are less complicated in design than most other bits, their manufacturing process is much simpler.
The end of the cylindrical steel blank is heated and drop forged into a flat spade shape. The process of drop forging involves a heavy piece of metal, such as a power hammer, stamping steel into a mould while it is hot, and so this method is particularly well suited to creating the spade bit's flat head.
The lips, spurs and centre points are then sharpened on a grinding wheel.
In some bits, a hole is drilled behind the central point to allow for a cable to be threaded through.
For more information, see:
The width of the bit is then stamped on the remaining flat space so it can easily be differentiated from others.