Fredsert Threaded Inserts

Why is a Fredsert, called a “Fredsert”?

Fredserts were initially designed for the Expeditionary Fighting Vehicle (EFV) by an Engineer named Fred Wheeler. Fred designed the product to meet the unique demands of the EFV program, which included a water-tight seal, solid locking to prevent back-out, corrosion resistance in extended saltwater exposure, and the ability to be easily removed and replaced in the field. The use of Fredserts has since expanded to a number of other applications both inside and outside General Dynamics.

What materials are Fredserts made from?

Fredserts are available in Titanium, Passivated Stainless Steel, Inconel, and Zinc-plated steel. For more details on these materials. For extremely corrosive applications, an electroceramic coating is available that eliminates potential for galvanic corrosion. For more details Extreme Corrosion.

How do Fredserts compare with competitive inserts, such as Keensert, Rosan or Helicoil?

One of the most unique features of a Fredsert is that it doesn’t permanently lock into place. Instead, its patented geometry causes it to break away at approximately 80% of the recommended installation torque value, allowing it to be quickly and easily removed and replaced using the same equipment. By comparison, other inserts on the market can only be removed by drilling them out and, in some cases, re-tapping to the next largest tap size. This drilling and/or tapping process is especially difficult if the insert is installed in a large structure or a tight enclosure because access and rigidity are limited. Another feature that sets Fredserts apart is the fact that Titanium Fredserts are available as a standard product, in addition to those made from Stainless, Inconel, and Zinc-plated steel. Titanium Fredserts deliver weight savings of 40% over steel inserts of the same size. Titanium inserts from other leading insert manufacturers are either not an option or they are quoted at a high price with several months lead time. A third key benefit that differentiates redserts from the competition is the fact that they create a watertight seal without the use of a thread locking agent, such as Loctite. The combination of a tapered thread profile, 100% thread engagement, thread of the insert. “Blind” Fredserts also deliver a watertight seal on the ID thread, because the ID thread bore doesn’t break through the bottom of the insert.

What equipment is required to install and remove Fredserts?

1. Installation tool (see “Drive Tool” column on standard Fredsert pages)
2. Allen head cap screw (See “Bolt Length” chart for lengths)
3. Allen wrench to assemble driver to Fredsert
4. Torque wrench with the proper torque range for insert being installed

Can a Fredsert be removed and reused?

Fredserts can be removed and re-installed, as long as there’s no damage to the insert or the tapped hole. This is not recommended on a repeated basis, though, because when you install a Fredsert, the cutting edges can eventually become dull, leading to galling of the threads in your parent material.

Is it necessary to begin screwing the Fredsert in by hand to get it started, prior to engaging the insert driver?

For manual installation, starting the insert by hand is important to avoid cross-threading the insert and damaging the tapped hole in the parent material. For high-volume Fredsert installations, drive tools are available that eliminate the need to assemble the driver to the insert with a bolt. These spring-loaded drivers enable Fredsert installation in a fraction of the time.

What happens if I break a bolt off inside the Fredsert?

If possible, remove the Fredsert with the bolt still in and replace with a new Fredsert in the same hole. If you can’t remove the Fredsert with the bolt still in, you’ll need to drill out the bolt, then check the internal threads of the Fredsert.

What should I do if I’ve reached the recommended installation torque value and the Fredsert is not yet ‘seated’ on the surface of the plate?

If you’ve reached the proper torque value and the Fredsert has yet to seat on the plate, you can go 10% above the recommended installation torque to see if it will seat. If it still will not seat, remove the Fredsert and run a tap down through the hole to clean out any burrs or debris that may be causing the problem.

When a Fredsert is being removed, at what torque value will it break-away and start to back out?

“Break-away value” is the torque that it takes to back the Fredsert out. After initial installation, break-away will be approximately 80% of installation torque value. If the same insert is re-installed into the same hole, the break-away value will be slightly reduced. The reason is that a Fredsert actually cuts material as it’s installed, so if you install a Fredsert into a hole for a second time, there’s no material to cut. Even so, the tapered thread profile, 100% thread engagement, and flanged head will still deliver a break-away torque of 65-75% of the recommended installation torque.

Is it necessary to use a thread-locking agent, such as Loctite, when installing Fredserts?

No. There is no need for using Loctite for installing a Fredsert, unless you are doing a repair procedure. The combination of a tapered thread profile, 100% thread engagement, and a flanged head deliver a perfect seal on the OD thread of the insert. “Blind” Fredserts also deliver a watertight seal on the ID thread, because the ID thread bore doesn’t break through the bottom of the insert.

When preparing a tapped hole to install a Fredsert, is it necessary to counterbore the hole?

The only reason to counterbore the hole is if the application requires that the insert mount flush with the material surface. Otherwise, the insert can be mounted “proud”, where the Fredsert flange sits on top of the material surface. Appurtenancestyle Fredserts are always mounted proud because they are used as a stand-off. There is no Fredsert performance difference between flush mount and proud mount.

How does a Fredsert lock into place?

The Fredsert geometry is effective in that it combines a tapered thread profile, 100% thread engagement, cutting flutes and a flanged head. These unique features deliver a combination of friction fit and material compression that reliably lock a Fredsert in place. Fredserts were designed to resist vibration, tensile loading and shear loading in the most demanding heavy-duty applications.

What effect does Fredsert Quality have on the installation process?

Fredserts are manufactured to tight specifications to ensure consistent and reliable performance. Fredserts are inspected on the latest visual inspection equipment to ensure tht the critical design elements are produced within specificiation. The Fredsert inspection process requires that manufacturers closely monitor quality,eliminating potential for variation.

Are Fredserts effective in applications where a water-tight seal is needed?

A key benefit that differentiates Fredserts from the competition is the fact that they create a 100% watertight seal without the use of a thread locking agent such as Loctite. The combination of a tapered thread profile, 100% thread engagement, and a flanged head deliver a perfect seal on the OD thread of the insert. “Blind” Fredserts also deliver a watertight seal on the ID thread,because the ID thread bore does not break through the bottom of the insert.

How does a user decide which Fredsert size to use?

The Fredsert size chosen depends on the bolt size being used in the application, as well as the thickness of the material it’s being installed into. The Fredsert product line has been developed with a generous safety factor between the bolt break-away torque and the Fredsert break-away torque to ensure that the Fredsert will not back out when the bolt is removed.

Are there applications where a Fredsert is not the best option?

The only case where competitive inserts have an advantage over Fredserts is in an application where the absolute minimum space claim is required. Because Fredserts feature a flanged head, they take up a slightly larger area than competitive inserts, such as Helicoil and Keensert.

How can I request a quote for a custom Fredsert?

Are Fredserts available for commercial use?

Who can I contact for Fredsert technical support?

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