Mechanical Properties
The mechanical properties listed in the following tables are given as a matter of general information. They do not form a part or requirement of any specification unless each instance is approved by the source of supply. The properties in these tables can generally be expected from bars in sizes ranging from 3¼4 to 1 1¼4 inches based on the standard round tensile test specimen with 2-inch gage length.
Sizes under 3¼4 inches will show slightly higher strength than those shown in the tables. The mass effect of larger sections has a direct influence on mechanical properties and results in slightly lower values as the section increases.
Properties of turned and polished or turned and ground types of cold finished material will correspond to the hot rolled values.
The cold drawn properties are based on conventional production from hot rolled bars. When required, these properties may be varied by modifled cold drawing practices or a combination of cold drawing practice plus thermal treatment for grades SAE 1050 and lower in carbon. Grades higher in carbon than SAE 1050 are commonly annealed before cold drawing.
Machinability Ratings
The machinability ratings listed are based on a value of 100% for SAE 1212 cold drawn. This value involves turning at a cutting speed of 180 surface feet per minute for feeds up to .007 inches per revolution and depths of cut up to .250 inches, using appropriate cutting fluids with high speed steel tools, SAE Grade T-1(18-4-1) hardened to 63/65 RC.
Relative machinability data shown in the tables represent results obtained from various experimental data and actual shop production information obtained from results of machining cold drawn bars on single and multiple spindle automatic machines. Various factors influence machinability and, therefore, results shown in the tables are average and may be affected to some degree by amount of cold reduction, mechanical properties, grain size, and microstructure.
NOTE: References: J414 and J770C SAE Handbook.
