Part of a System of Access Wrenches – Tekton service wrenches are short-handled, open-end access wrenches with a 15-degree angled head on one side and a drive square on the other, and they complement our other access wrenches, Drive Square in Handle – The drive square can be used with a ratchet or other drive tools to increase access or leverage and apply specific torque; four detent grooves secure the connection, Thin Jaw for More Access – Our service wrench jaws are much leaner than our standard combination wrenches, with 33% to 46% less jaw thickness (depending on the size), providing better access in tight spaces and on thin fittings, 4140 Steel, Satin Nickel Finish – We make our service wrenches from 4140 chromium molybdenum steel and harden them to 50–53 HRC, then abrasive-blast them.