McMaster 90725A740 Zinc-Plated Steel High Hex Nut Class 8, M20 x 2.5 mm Thread PK5

Slightly taller than standard-profile hex nuts, these have a larger gripping area so your wrench or socket won't slip off as you tighten them. They're often used in vehicles and machinery where fasteners can be difficult to reach.

Medium-Strength Steel—These Grade 5 or Class 8 nuts are your go-to for fastening most machinery and equipment. To avoid stripped threads during installation, make sure your screw has a comparable strength rating.

Zinc-Plated Steel—A step up from plain steel, the zinc plating withstands occasional exposure to moisture.