Properties Of Steel

: The Working Of Steel

Steels are known by certain tests. Early tests were more or less

crude, and depended upon the ability of the workman to judge the

grain exhibited by a freshly broken piece of steel. The cold-bend

test was also very useful--a small bar was bent flat upon itself,

and the stretched fibers examined for any sign of break. Harder

stiff steels were supported at the ends and the amount of central

load they would support before
fracture, or the amount of permanent

set they would acquire at a given load noted. Files were also used

to test the hardness of very hard steel.

These tests are still used to a considerable extent, especially in

works where the progress of an operation can be kept under close

watch in this way, the product being periodically examined by more

precise methods. The chief furnace-man, or melter, in a steel

plant, judges the course of the refining process by casting small

test ingots from time to time, breaking them and examining the

fracture. Cutlery manufacturers use the bend test to judge the

temper of blades. File testing of case-hardened parts is very common.

However there is need of standardized methods which depend less

upon the individual skill of the operator, and which will yield

results comparable to others made by different men at different

places and on different steels. Hence has grown up the art of testing