I use my old abattoir knives, put a serrated edge on one side for heavy roots, heat treated and regularly sharpened, no blisters without gloves, or searing handles in the heat, get a few funny looks at times but yet to find anything better for no kill plug cutting. Slips in leather pocket while detecting. Can't beat a plug with an Inox boning knife but there are laws against knives in vehicles. The thin edge allows the draw out of a solid cone shape Paramount for keeping the pre decs in as is condition. Some great options above.