Our fully threaded hex head cap screws carry the thread all the way up to the head, which gives you full engagement in tapped holes and lets you adjust grip length on the job. The six sided head takes a standard wrench or socket for solid, repeatable torque. Available in class 8.8, 10.9 and 12.9 steel and A2/A4 stainless.

Hex Head Cap Screw Full Thread: Metric Sizes

What Is a Fully Threaded Hex Head Cap Screw?

A fully threaded hex head cap screw is a six sided fastener with thread that runs the whole length of the shank right up to the underside of the head. Because there is no plain shank section, you get thread engagement across the entire grip, which is what you want when the joint depth changes or when you are threading into a nut, a tapped hole, or an insert. The hex head seats a wrench or socket on six flats, so you can reach the torque the joint needs and repeat it part after part.

The full thread form makes this screw a flexible choice for shops that carry a smaller range of lengths. One length can cover several grip depths since the thread is always there to bite. It is a common pick for machine building, brackets, frames, and general maintenance where a clean six sided drive and reliable clamp load matter more than a shoulder of plain shank.

The term cap screw points to how the part is used rather than how it is made. A cap screw is meant to thread into a tapped hole or a nut and be tightened to a set clamp load, and it is finished to a tighter tolerance under the head so it seats squarely. That square seat matters because a head that beds flat spreads load evenly and holds tension better over time. When the thread runs all the way up, the last thread meets the head cleanly, which keeps the bearing face true and helps the joint stay tight.

Key Features and Benefits

• Thread to the Head: The thread runs the full length, so you get engagement across the whole grip and can tune length to the joint.
• Six Sided Drive: The hex head takes a standard wrench or socket for high, repeatable torque without a special tool.
• Strong Clamp Load: Higher property classes let the joint carry heavy static and shifting loads.
• Flexible Lengths: One fully threaded length can serve several grip depths, which trims the number of parts you stock.
• Steel and Stainless: Plated steel for strength and stainless for corrosion resistant service.

Materials and Finishes

• Alloy Steel (Class 8.8, 10.9, 12.9): Heat treated for higher tensile strength where the joint carries real load.
• Carbon Steel (Zinc Plated): A plated finish for general assembly and indoor work.
• Stainless Steel (A2 / A4): For marine, outdoor, and corrosion prone environments.

Common Applications

Fully threaded hex head cap screws show up wherever a strong, adjustable clamp is needed and a plain shank is not required to locate parts. They anchor motors, gearboxes, and pumps to frames and base plates. They hold guarding, covers, and access panels that come off for service. They join steel and aluminum brackets, and they mate with weld nuts and threaded inserts in fabricated assemblies.

Because the thread reaches the head, these screws also work well in blind tapped holes where the joint is shallow. You want as much thread as the hole will take, and full thread gives you that without having to hunt for the exact grip length. Maintenance teams like them for the same reason, since one box of a given size and length can fix many different joints on the floor.

How to Choose the Right Screw

Start with the property class the joint needs. Class 8.8 covers most general assembly, while 10.9 and 12.9 step up the tensile strength for heavily loaded or safety related joints. Match the class of any nut you pair with the screw so the nut is not the weak point. Next, set the length so the screw fills the tapped depth or leaves enough thread through a nut for full engagement, usually at least the nut height. Finally, pick the finish for the service, with plated steel for dry indoor work and A2 or A4 stainless where moisture or salt is present. When mixing stainless fasteners, a touch of anti seize helps guard against galling on final torque.

Standards Compliance

• DIN 933 / ISO 4017: Fully threaded hex head screws
• ISO 898-1: Mechanical properties for steel fasteners
• ISO 261: Metric coarse thread pitch

Size Range and Availability

Available in M3 through M24 in metric coarse thread, in class 8.8, 10.9 and 12.9 alloy steel and A2/A4 stainless steel. If you need a size, class, or finish that is not shown, reach out and we will help you source it.

Frequently Asked Questions (FAQs)

1. What is a fully threaded hex head cap screw used for?

It is used for machine building, brackets, frames, and general maintenance where you want the thread to run the full length so it engages across the whole grip and threads into nuts, tapped holes, or inserts.

2. What is the difference between full thread and partial thread?

A fully threaded screw has thread up to the head with no plain shank. A partial thread has a smooth shank under the head, which some joints use to locate parts or carry shear across the plain section.

3. When should I choose full thread?

Choose full thread when joint depth varies, when you thread into a nut or tapped hole, or when you want to keep fewer lengths in stock while still getting full engagement.

4. What property classes do you stock?

We stock class 8.8, 10.9 and 12.9 in alloy steel, along with A2 and A4 stainless for corrosion resistant work.

5. Do these take a standard wrench?

Yes. The six sided head takes a standard metric wrench or socket, so no special driver is needed.

6. What thread type do these use?

They use standard metric coarse thread and mate with tapped holes, threaded inserts, or nuts of the same specification.

7. Are these available in stainless steel?

Yes. We stock them in A2 and A4 stainless along with plated and alloy steel options.

8. What sizes do you stock?

We stock M3 through M24 in metric coarse thread across steel and stainless.