Steel 9/16 welch plug for early engine cases are used to form the internal cavities in the engine case forming a coolant passage. Welch plug is used to seal passages created for internal oiling on oil pump body and engine case. The welch plug expands for a permanent seal when hit with dull punch plugs are not reusable. Check the outer diameter of the plug before installation. The welch plug are what the Harley-Davidson factory used for many years. Welch plugs manufactured since 1909 in the U.S.A.
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ACCESSORY ITEMS