longhunter Posted February 16, 2009 Share Posted February 16, 2009 Anyone know what the carbon content is of grade 8 bolts are I have some that are 1" dia and 6-7 " long tying to think of some good use's Quote Link to comment Share on other sites More sharing options...
Glenn Posted February 16, 2009 Share Posted February 16, 2009 What is Grade 8 (bolts, metal) Quote Link to comment Share on other sites More sharing options...
longhunter Posted February 16, 2009 Author Share Posted February 16, 2009 So Glenn have you used them in some forging projects ? Quote Link to comment Share on other sites More sharing options...
Woody Posted February 16, 2009 Share Posted February 16, 2009 Be careful with Grade 8 bolts, if they have a gold color they might be cadmium coated, others may be zinc coated. Several years ago there were a multitude of "counterfit grade 8 bolts on the market" They were sold as grade 8 but did not meet the specs. The Tank Truck Magazine "Modern Bulk Transporter" ran an article on them identifying all the different counterfit bolts by their manufacture and markings about 1992 or so. Woody Quote Link to comment Share on other sites More sharing options...
nitewatchman Posted February 17, 2009 Share Posted February 17, 2009 The starting material for SAE J429 Grade 8 Bolts is usually AISI C4140 or C4150 hence .40% or .45% Carbon. Grade 8 bolts are identified by 6 radial lines on the bolt head. Grade 5 Bolts usually start as AISI C1045 or .45% Carbon. Grade 5 bolts are identified by 3 radial lines on the head. There are exceptions, some ASTM A325 or SAE J429 Grade 5 bolts have been made of AISI C10B22. This material has only .22% Carbon but hardens due to the addition of .003% Boron. Heat Treating this material my prove difficult without accurate temperature control. nitewatchman Quote Link to comment Share on other sites More sharing options...
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