Hot Deal 5/16″-18 X 3″ Machine Screws Indented Hex Washer Head Steel Zinc Plated (400/Pkg.)

Engineered for durable metal-to-metal fastening, these machine screws feature an unslotted indented hex washer head and a zinc-plated finish for superior corrosion resistance. Sized at 5/16-18 with a 3-inch length, they are a common choice for machinery, automotive, and metal fabrication projects.

Key features

Head: Indented hex washer, unslotted

Drive: Hex drive

Thread & length: 5/16-18, 3 in

Material & finish: Zinc-plated steel

Applications: Ideal for metal-to-metal fastening in equipment, panels, chassis, and other metal assemblies

Why choose zinc-plated machine screws?

The zinc plating provides a durable barrier against moisture and chemicals, helping extend service life in indoor and mild outdoor environments. The indented hex washer head helps seat the fastener flush and distribute load effectively, while the unslotted design reduces the chance of slippage in certain high-torque installations.

Installation tips

Pair with compatible nuts or tapped holes. Use a matching hex driver to engage the indented head, and tighten to the recommended torque for your application to ensure a secure fit without over-tightening.