Amazon.com: AC PERFORMANCE Aluminum M18x1.5 to 5/8 barb Fuel Oil Pump Inlet outlet fuel regulator Fitting, Male Metric to outer diameter 15.88mm 5/8" barb push on fitting with Washer, Black : Industrial
15 mm x M18x1.5 O-Ring Thread L Series Male Stud – Alabama Industrial Products
Mild Steel M18X1.5 Thread Bung and Plug Kit – 37350