Click Image to Enlarge Figure 4. Two major chip types: spiral-
and comma-shaped chips. A small depth of cut produces spiral-
shaped chips (above, left), and a longer depth of cut leads to
comma-shaped chips. Figure 1. There are three types of chip
formations: (A) self-breaking, (B) breaking against the tool,
(C) breaking against the workpiece. Some people say "reading"
chips is like reading tea leaves, albeit much more rooted in
science than in conjecture. If you master chip reading, you'll
control throughput, turning costs, tool life and surface finish,
leading to better process economics and increased process
security. These issues are particularly timely today, because
many companies are operating multiple shifts to meet growing
market demand and running "lights out," unattended turning
operations. By interpreting chip size, shape, color, and
direction, you will know how effectively your tools and machines
are performing. You'll also have peace of mind regarding
unattended operation, because chip disposal i