Weldmark® by Tweco® 11H Series Heavy Duty Contact Tip accommodates 0.045" wire and is perfect for use with 160 - 250 A Tweco® No.1 MIG gun as well as specific MIG gun series. Contact tip with excellent electrical properties is ideal for use in heavy-duty welding application up to 200 A. It features part number and wire diameter for easy identification. 1" Contact tip with M6 X 1.0-6g thread size has 0.054" nominal ID and 0.283" OD. Contact tip is made from extruded or gun-drilled 122 DHP copper alloy and machined from a copper alloy tubing to offer a consistent as well as smooth surface of inside diameter with +/-0.003" tolerance. It has threaded style that ensures proper contact with a gas diffuser when installed to the MIG gun. It comes in slip-on or thread-on nozzle styles with a choice of diameter bore sizes. Contact tip locks in place when twisted and offers better electrical conductivity with increased surface contact. Contact tip features thick-walled design that acts like a heat sink conducting heat away from the arc source. It can be twisted quarter turn clockwise when tip wear point is reached that reveals a new wear point for doubling the life of the tip. Contact tip is sold as 25 per pack.