Reciprocating saws are indispensable for
demolition work. They save time, and for
some cuts they're the most practical
power tool on the job site. Years ago,
however, the usefulness of a recip saw was limited
by the short service life and cutting capability of
the blades. Most early blades were made of highcarbon
steel, approximately .035-inch thick, hardened
to about Rockwell 65. These inexpensive
blades could perform general cutting tasks, but
there was a tradeoff between flexibility and durability.
Steel that could be sufficiently hardened to
provide a good cutting edge
lacked the tensile strength
and flexibility that would
allow it to hold up under severe use, like cutting
nail-embedded wood. To improve performance,
engineers were faced