Carbon Steels For Different Tools

: The Working Of Steel

All users of tool steels should carefully study the different qualities

of the steels they handle. Different uses requires different kinds of

steel for best results, and for the purpose of designating different

steels some makers have adopted the two terms temper, and quality,

to distinguish between them.

In this case temper refers to the amount of carbon which is combined

with the iron to make the metal
nto a steel. The quality means

the absence of phosphorous, sulphur and other impurities, these

depending on the ores and the methods of treatment.

Steel makers have various ways of designating carbon steels for

different purposes. Some of these systems involve the use of numbers,

that of the Latrobe Steel Company being given herewith. It will

be noted that the numbers are based on 20 points of carbon per

unit. The names given the different tempers are also of interest.

Other makers use different numbers.

The temper list follows:


No. 3 temper 0.60 to 0.69 per cent carbon

No. 3-1/2 temper 0.70 to 0.79 per cent carbon

No. 4 temper 0.80 to 0.89 per cent carbon

No. 4-1/2 temper 0.90 to 0.99 pet cent carbon

No. 5 temper 1.00 to 1.09 per cent carbon

No. 5-1/2 temper 1.10 to 1.19 per cent carbon

No. 6 temper 1.20 to 1.29 per cent carbon

No. 6-1/2 temper 1.30 to 1.39 per cent carbon

No. 7 temper 1.40 to 1.49 per cent carbon