18-3721-9 Stainless Steel Locknut (Priced Per Pkg of 5)

Sierra Stainless Steel Locknut-  18-3721-9

Material: Stainless Steel w/ nylon insert
Thread Size: 7/16" or 11.1mm - 20
For: MCM inner transom studs and prop nut for Mercury 39, 60 (1968 & newer, 8 spline)
For: MR/Alpha

Interchangeable with the following:

GLM
21170

Mercruiser Stern Drive
11-21298
11-22178
11-24648
11-29241
11-33962
11-34933
11-82671015

Mercury Marine
11-134391
11-22178
11-34933
11-46355
11-82671015
11-859116
11-8M0204653
11-95702