Bright steel bars are carbon steel which has had the surface condition improved over the hot rolled finish supplied by the steel mill. Advantages achieved include improved machinability, enhancement of physical and mechanical properties and improved dimensional tolerances and straightness.

Cold finished steels are covered by Australian Standard AS1443. 

Cold drawn bars are widely used in mass production of parts due to their excellent mechanical and dimensional properties, with machinability in excess of the hot rolled condition. Round, hexagonal and square bars can be produced by cold drawing.

Turned and polished round bars have similar mechanical properties to those of equivalent hot rolled bar, but exhibit a smooth, bright surface finish and improved dimensional accuracy. They are widely used where a surface free of decarburisation is required, for example in induction hardening and when the surface must be free from surface defects, such as for use in cold forming.

Cold drawn and precision ground or turned and precision ground round bars, where very close dimensional tolerances and finishes are required, e.g. plating.

Cold rolled sizes up to 100mm wide and 7mm thick inclusive are produced by cold rolling to produce flat and some special shape sections to suitable tolerances and surface finishes.

 

Current Steel-Making Practice

Old Prefix	New Prefix	Practice	Example of Old Prefix	Example of New Prefix
R	U	Steel with unspecified deoxidisation (no minimum % Si specified)	R1008	U1004
S	U		S1010	U1010
CS	M	Merchant quality. Similar to "U" with wider composition range	CS1020	M1020
K	No prefix	As per relevant table in Standard	K1045	1045
X	X	A major deviation in chemical composition from AISI-SAE grades	XK1320	X1320