T-H Marine T H Marine Jack Plate Bolt Kit Coarse Thread. We are a family owned business that has been serving the marine industry since 1975. Kit Contains: four 1/2" x 3" stainless steel long bolts four 1/2" brass lock nuts eight 1/2" flat stainless steel washers Features of T-H Marine BK-1-DP T H Marine Jack Plate Bolt Kit Coarse Thread For mounting outboard to plate Four 1/2" x 3" stainless steel long bolts Four 1/2" brass lock nuts Eight 1/2" flat stainless steel washers Package Contents: T-H Marine BK-1-DP T H Marine Jack Plate Bolt Kit Coarse Thread T-H Marine BK-1-DP: T H Marine Jack Plate Bolt Kit Coarse Thread