Engineering Term of the Month
Mill Secondary Steel Pipe Steel pipe is used for many structural applications , including use in foundations ( piles ), flagpoles , sign piles , bridge railings , and culverts . The steel pipe can be classified as “ prime ” or “ mill secondary .” Prime steel is steel that passes all manufacturing and inspection tests in manufacturing and is available on the “ primary ” raw markets market . Mill secondary steel consist of the materials that do not meet the order requirements to be classified as “ prime .”
Steel pipe may be classified as secondary due to not meeting the exact requirements of a specific order due to some physical or chemical variance specific to the client ’ s requirements . However , it does not necessarily mean that the steel is of less quality , depending on the use of the material .
Foundation micropiles are an effective use of mill secondary steel . Coupon tests are used to verify the steel strength and ductility through tensile and chemical testing of steel samples . For the purpose of foundation micropiles , the use of prime casing rather than mill secondary can unnecessarily increase the cost significantly , without benefit . The use of mill secondary steel for micropiles has been the industry standard . Projects required to meet the Buy America Act ( 1983 ), Buy American Act ( 1993 ) and American Recovery and Reinvestment Act ( 1993 ) require mill certifications be provided to prove domestic origin ; however , such certifications are not available for mill secondary materials
Sources :
• Geo-Strata , September / October 2012 , ‘ Buy America ’ Act Threatens U . S . Micropile Business , Bennett , Jonathan K .
• jltubulars . com / new-mill-secondary-tubular-products /
• www . pipelineequities . com / tag _ secondary _ pipe . php
• www . eiffeltrading . com / blog / post / eiffel-trading-101-difference-between-primary-and-secondary-used-surplus-steel pipe
• micropileman . wordpress . com / 2010 / 10 / 29 / mill-secondary-material-for-micropile-casing /