5/8"-18 Polished 18-8 Stainless Steel Fine Thread Acorn Nuts (3 pcs.)

Diameter: 5/8"
Diameter 2: 1-1/16"
Thickness: 1-11/32
Material: Stainless Steel
Finish: Polished
Driver Type: 15/16" Wrench
Thread Size: 18 (Fine)
Shape: High Crown Acorn
Hardness: 18-8
Type: Cap Nut

Box of 3.

A closed nut having a dome-like cap over the back, protruding part of the engaged screw or bolt. Also called an acorn nut.