HOT ROLLED or COLD FINISHED
Which should you use?
The choice depends upon the purpose. Hot rolled bars, without any further finishing, are chosen for many general uses, thus saving you money. However, it may pay you to use Cold Finished bars which cost more at the start, but which may save you money, time and trouble in the long run. Cold finishing, which usually consists of cold drawing and/or turning, grinding and polishing, results in higher yield points and has these four main advantages:
The first is finish. Cold drawing through a die imparts a bright new surface.
The second advantage is size tolerance, concentricity, and straightness. C.F. bars are close dimensionally and in roundness. A 1” diameter C.F. bar of AISI 1018 is plus 0.000 in, minus 0.002 in. A hot rolled bar of the same diameter is plus or minus 0.009.
The third advantage is cold drawing. Cold drawing increases the yield and tensile strengths, often eliminating further costly thermal treatments.
The fourth and the most important for many jobs is machinability, which is often improved by as much as 20%. This can mean savings through increased tool life, higher cutting speeds and a better surface finish.
We would be glad to advise as to the right bar to choose for any specific purpose. We carry in stock eleven types of Hot Rolled Bars and eight types of Cold Finished – a wide enough choice to meet virtually every need.