This is part 2 of David Pye's series on the heat treatment of small arms, guns and rifle barrels.

This is the first of several blogs that will describe some of the heat-treatment practices conducted on, handguns, rifle barrels, sniper barrels and artillery (155-mm howitzer).

David Pye's blog series on hardness testing continues ... and concludes with part 11.

David Pye's series on hardness testing continues with part 10.

In 1939, Frederick Knoop and his colleagues at The National Bureau of Standards submitted an alternatively designed indenter based on a rhombohedra-shaped diamond whose long diagonal was approximately seven times as long as the short diagonal.

David Pye's blog series on hardness testing continues.

David Pye's series on hardness testing continues.

David Pye's series on hardness testing continues.

This is part 5 of David Pye's series on hardness testing.

This is part 4 of David Pye's series on hardness testing.