ASME B18.31.5 pdf download Bent Bolts (Inch Series) 2.5 Ends For bolts made with UNC threads, the ends shall be chamfered or the first thread rolled undersize. For bolts made with UNF threads, the ends shall be chamfered. 2.6 Materials Unless otherwise specified, the products in this Standard shall be made of low carbon steel as defined here as steel...