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A Design Study in Steel - Cast Connex Steel Construction Connector

Steel Alloy Selection

Cast Connex  design engineers originally considered three different steel casting alloys, as specified by ASTM standards.   

ASTM  A27 Grade 70-40  Carbon Steel Casting for General Application
          Composition = 0.25 C max, 1.20 Mn Max, 0.80 Si Max, 0.06 S Max, 0.05 P Max
ASTM  A148 - Grade 80-50  High Strength SteelCastings for Structural Purposes
          Composition = C, Mn, Si, S per agreement;  0.06 S Max, 0.05 P Max
ASTM A958 - Grade 8620, Class 80/50
  Steel Castings with Tensile and Chemical Requirements Similar to Wrought Grades
          Composition =  Min/Max Specified for C, Mn,  Si, Ni, Cr, Mo; Max for S and P. 

The three specifications gave the following properties for the three  alloys.   


A27 Grade 70-40 A148 Grade 80-50 A958 Grade 8620
 Minimum Ultimate Tensile Strength  80 ksi 70 ksi min 80 ksi min 80 ksi min
 Minimum Yield Strength  50 ksi 40 ksi min 50 ksi min 50 ksi min
Minimum Elongation  22% 22% min 22% min 22% min
Minimum Reduction of Area 35% 30% min 35% min 35% min
Chemistry Control Very Tight Max Values Specified,  Max Values for S and P Max/Min Values for  all
Heat Treatment Spec. and Control Very Tight Not Specified Not Specified Specified
Given the mechanical property and process control requirements for the connector
Choose the best alloy - A27, A148, OR A958


Choose an alloy  above


Copyright 2009  by the Steel Founders' Society of America   All rights reserved. 
Address comments to: blairr@sfsa.org
Last Modified:June, 2009 by STG

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In cooperation with Cast Connex and Pacific Steel Castings