Saw the darndest nozzle cleaner ever. Welders were pulling off the nozzels from their Tweco #4 guns and inserting a #8 grade bolt of first a 1 / 2 inch diameter and then a 5 /8 inch diameter (for a 5 / 8 inch nozzle). They inserted the bolt from the rear end and with a four inch bolt that stopped when it hit the spatter buildup. Then they smacked the head of the bolt driving out the spatter. This left a clean smooth bore. Much better than a rat tail file. There was no egg shaping as with a "whelper".