Tweco® 1/16 inch VELOCITY2™ VTET Series Contact Tip. Tweco® Velocity. We listened to welders and they said, -˜fewer tools and fewer threads'. The outcome is a design that is simpler, requires no tools and virtually eliminates problems with threads. Typical MIG consumables have TWO sets of threads and many have THREE - Velocity has reduced this down to ONE set. Also, Velocity's mating threads share a soft material (brass) along with a hard material (stainless steel). The combination of soft threads against hard reduces seizing and cross threading. Heat-treated stainless threads on the gooseneck are virtually indestructible and the brass threads on the replaceable nozzle are softer, so they grip and won't loosen.