Is this Cobalt or HSS?

M7 is a high speed steel -- I don't believe it contains any cobalt. M42 is probably the most common cobalt HSS.

FWIW, all "cobalt" tools are actually classed as high speed steel. M42 is the most common of the "cobalt" high speed steel grades, with 8% cobalt. You'll also see M35 (5% cobalt), and many of the high-end proprietary grades contain various amounts of cobalt.

M7 is a tough HSS with good overall properties, often chosen for use in portable industrial drills because it will tolerate some off-axis loads and rough handling. It contains no cobalt.

-- Ed Huntress

Thanks for the help here, gentlemen, I appreciate it.

Kind regards.

Lewis.