Definition(s)
Equivalent Round (ER)
Standard for comparing various shaped sections to round bars, in determining the response to hardening characteristics when heat-treating low-alloy and martensitic corrosion-resistant steel.
Source: API SPEC 6A, Specification for Wellhead and Christmas Tree Equipment, Twentieth Edition, October 2010 (Addendum November 2012). Global Standards
Equivalent Round (ER)
Standard for comparing variously shaped sections to round bars, used in determining the response to hardening characteristics when heat treating low-alloy and martensitic corrosion-resistant steels.
Source: API SPEC 7K, Drilling and Well Servicing Equipment Upstream Segment, Fifth Edition, June 2010 (August 2010). Global Standards