You just have to have to place the wire between the jaws and close. The spherical jaw will press the wire in to the concave leading to a good half circle loop. Concave pliers also are superior for wire wrapping jewellery craft. For instance, you’ll see lots of Wubbers brand https://diy-project-ideas42959.eqnextwiki.com/4558585/hand_tools_for_diy_an_overview