Sierra Stainless Steel Locknut Priced Per Pkg Of 5

Sierra 18-3721-9 Stainless Steel Locknut for Mercury & Mercruiser Engines - 5 Pk

Sierra high-quality engine parts are designed to meet OEM specifications. Stainless Steel locknuts with nylon inserts.

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 engines

Interchangeable with:

GLM

21170

Mallory

9-72004

9-72004-10

Mercruiser Stern Drive

11-29241

11-24648

11-21298

11-22178

11-82671015

11-33962

11-34933

Mercury Marine

11-95702

11-46355

11-34933

11-82671015

11-22178

11-859116

11-134391