... Stainless Steel Hollow Bolt,Bolt with Internal Thread.1.What’s the specification of our Products ? MaterialsCarbon steel,Stainless steel,Alloy steel,Copper,Aluminum are available.Carton steel ... 45#,10B21,1035,CH38F,1039,40ACR...Alloy steel are 35,40CrMo,SCM435,10B38...Stainless steel is SS201,202,302,304,316... ... to call me any time !Tel:+86-15917002605 Stainless Steel Hollow Bolt With Internal Thread