Difference between Hot Rolled & Cold Rolled Steel Round Bars

Hot Rolled Steel Round Bars

Hot rolled steel round bars are simpler to form, shape and form. It has its origin in the mill process involving rolling the steel at high temperatures. It starts with being heated at 926° Celsius then the steel is rolled through the press into the desired shape. The whole process is done at very hot temperatures and at the end cooled down. The cooling down may cause the steel to shrink, so there’s less control over the final size and shape. Hot rolled steel is typically used when precise shapes and tolerances aren’t essential.

Advantages

  • Cheaper than cold rolled steel round bars
  • Hot rolled steel round bars are allowed to relax down at normal temperature and made free from internal stresses which can arise from hardening processes

Disadvantages

  • Dimensional uncertainties are caused due to heating and cooling down
  • The rough texture on a surface has to be removed and buffed before painting
  • Slight distortions

Cold Rolled Steel Round Bars

Cold-rolled steel round bars are heated and cooled to normal temperature, then rolled again. The steel is then processed further in a cold reduction press, where the metal is cooled again followed by forming material by cold rolling to achieve the required shape.

Advantages

  • Accurate shape (consistent and straight)
  • A wider range of surface finishes
  • A smooth and shinier surface
  • Bars have well-defined edges and corners

Disadvantages

  • More expensive than hot rolled steel round bars
  • Fewer shapes are available in the cold-rolled round bars variety
  • More prone to warping due to internal stress on the inside

How to differentiate them?

Hot rolled steel round bars come with scales, rounded edges and their surface is non-greasy. Whereas, Cold rolled steel round bars have a greasy finish, a smooth-to-touch surface, and precise sharp edges.

Piyush Steel Round Bars is a very reputed exporter of Round Bars of various materials, sizes and specifications.

Read more about Stainless Steel Round Bars – Applications and Uses