Eureka Reporter | 1907-07-05 | Page 5 | For Hardening Drill

for hardening drill hardening an ordinary drill in eul mul pharic acid states the english mechanic machanic makes an edge that will cut tempered steel or facilitate cutting hard rock the add acid should be poured into a flat bottomed vessel to a depth of 0 about one eighth ot of an inch the point of the drill is heated to a dull cherry red and dipped in the acid to that depth this makes the point extremely hard bard while the remainder remains soft it if the point breaks but with a little less acid la in the vessel once in a while the voters get buy and elect an honest man