Material Grade Material Grade ZHIYAR (Mechanical) (OP) 8 Aug 17 04:13 Dears Can I use fitting material A420 WPL6 instead of A234WPB. Regards RE: Material Grade XL83NL (Mechanical) 8 Aug 17 08:59 That depends on a number of factors, like the application, service conditions, design code, engineering secifications, etc.. Without such information questions like these are impossible to answer. RE: Material Grade david339933 (Industrial) 8 Aug 17 14:54 Keeping in mind what XL83NL stated, often yes. SA420 WPL6 is often used in lieu of SA-234 WPB when impacts are required.