part number: MS21025-24 MS21025-24 HEXAGON CASTLE NUT Hexagon castle nut For gears with 1.5 inch drilled axles Applicability: Ercoupe (serial numbers 813 and up), Piper PA-18 Material: Steel, cadmium plated Thread: 1-1/2-16 Supercedes part numbers F33213, 415-33213 Dimensions: A: 1-3/4 inch B:... MSRP: Now: $25.26 Add to Cart part number: MS21025-24 MS21025-24 HEXAGON CASTLE NUT MSRP: Now: $25.26 Add to Cart