SOFTENING HARD CAST-IRON.

Wairarapa Daily Times, Volume 6, Issue 1744, 24 July 1884, Page 3

SOFTENING HARD CAST-IRON.

Softening hard cast-iron forms the subject of mi interesting letter from a correspfindeiitofllic American Machinist, who lias been experimenting successfully in that line. After narrating his failure to elfect the desired object fby heating the casting red hot and plunging it in cold water in that condition, as he was led to believe was correct, he gives the result of his experiments as follows:—"I thought I would try a way of my own. I heated the iron reel hot, and then held it in a dark corner, between the water barrel and forge, until I saw the. redness of the iron leave it, I then dipped it in water, holding it there till cool, I then tried it with a iile, and found it to be soft enough to be filed, I tried anotherjthc same way with the same result; one week after this, a «ken cast-iron handle was brought in be fixed; it was so hard that the boy who was a', work at it said he could not drill it, although the drill had been hardened as hard as the blacksmith could make it. I took it, ■went to the forge and treated it as before, with the same result. But it was new to the blacksmith, and before a., I tried it he said,' You will get left on f that.' ' All right,' replied I. After softening it, I went over to the same drill the boy had been using, and called him over to see me drill it, I drilled ut hole through it with perfect ease, He was surprised, and said, ' I give in.' I was surprised myself at its softness. I have travelled a great deal for the purpose of learning, and ■ have worked in many different shops where the men had to dress their own tools, but I never saw a man soften a hard piece of cast-iron in the same way as I did."