... & external threading insert SIZE :11ER/16ER/22ER 11IR/16IR/22IR etc.. Items are ISO,A,AG,G,W ... ,UN,NPT,ACME,API carbide internal & external threading insert SIZE RANGES ... ARE 11ER/16ER/22ER11IR/16IR/22IR etc..Items are ISO,A,AG,G ... for processing stainless steel(grooving insert) or universal use(threading insert). LDC shows yellow coating,suitable ...