Hard-to-Find Fastener Grade 5 Hex Cap Screws, 5/16-18 x 1-Inch, 100-Pack

For a repair or assembly that calls for a coarse-thread 5/16-18 fastener, this 100-piece set provides one-inch Grade 5 hex cap screws in alloy steel with a zinc finish. The hex head is sized for a 1/2-inch wrench, so the key buying question is whether those dimensions and the specified grade match the job—not simply whether a hex screw will fit.

A 100-piece pack suits someone keeping a supply on hand for multiple projects better than a buyer who needs only a few fasteners. The product description lists uses across home, farm, business, automotive, and industrial settings, but that range does not mean this screw is appropriate for every application.

Strengths

The listing gives the details that matter for matching a fastener: 5/16-inch diameter, 5/16-18 coarse thread, one-inch length, Grade 5, alloy steel, and a hex head. That makes it easier to compare the screw with an existing fastener or a project specification before buying. The 100-piece quantity may also be practical when a project calls for several matching screws or when you want spares from the same pack.

The zinc finish is described as providing some added rust resistance over steel. That is a useful distinction for general-purpose selection, but it should not be read as a claim that the screws are stainless or suitable for every exposure. If corrosion resistance is a central requirement, the source notes that coated and stainless fasteners are also available as alternatives.

The essentials

These are hex cap screws with a coarse 5/16-18 thread and a one-inch length. The stated wrench size is 1/2 inch. The material is alloy steel, the manufacturer grade is Grade 5, and the exterior finish is zinc. The listing calls the thread NC, consistent with its stated coarse-thread description.

For a practical example, someone replacing a group of screws in an assembly could use the pack if the required thread, length, head style, grade, and finish all match the project. Matching only the diameter is not enough: thread size and length also determine whether a fastener is appropriate. A smaller pack would make more sense for a one-off repair with only a few required screws, this set favors having a larger quantity available.

Getting the most from it

Before installation, compare the screw with the project's requirements or the fastener being replaced, including thread and length. The product description cautions that not every fastener suits every application and recommends thorough testing. Where failure could cause property damage or personal injury, it advises seeking the opinion of a licensed builder or certified building or structural engineer. That guidance matters more than the broad list of possible settings in the listing.

A solid pick if you need a bulk supply of this specific Grade 5, zinc-finished, coarse-thread size and a hex head that works with a 1/2-inch wrench. It’s not for you if the job calls for a different thread, length, head style, or material, those are fixed specifications here, not adjustable features.

Buying verdict

This pack is easiest to justify when the project specification already calls for 5/16-18 x 1-inch Grade 5 hex cap screws and you have a reason to keep 100 on hand. Its material and zinc finish are stated clearly, but the listing does not establish suitability for a particular load, environment, or safety-critical use. Choose it by matching the required fastener details, rather than assuming the general-purpose description covers every job.