TC Bolts Including A325, A490, And Galvanized Tension Control Bolts

Tension control bolts, also called TC or twist-off-bolts, are construction fasteners that connect steel joints in structural applications. They are considered high-strength bolts, which contribute to long-lasting steelwork connections.

TC bolts are provided as a fastener assembly, complete with a nut and washer, which means that time and labor are saved during installation.

A non-obstructive, low-profile makes TC bolts suitable for use on visual parts of a structure. In addition to ease and speed of installation, their design directly contributes to the maintenance of correct tension. The tension of the bolt refers to the stretch or pull of the bolt that contributes to proper tightening of the nut and bolt.

Two major factors contribute to the self-calibration of these bolts. The first is lubrication. The second is the depth of the groove between the spline and the threaded portion that comprises the bolt. The combination of these two factors is crucial in enabling the spline to sheer off once the bolt reaches the correct tension. This is what makes TC bolts self-calibrating and directly contributes to a quick installation process and overall reliability.


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Name
Spec
Finish
Length
Thread
Dia
Min-Qty
Price
F1852 OR A325
Plain
2 3/4"
7 UNC
1 1/8"
F1852 OR A325
Plain
3"
7 UNC
1 1/8"
F1852 OR A325
Plain
3 1/2"
7 UNC
1 1/8"
F1852 OR A325
Plain
3 1/4"
7 UNC
1 1/8"
F1852 OR A325
Plain
3 3/4"
7 UNC
1 1/8"
F1852 OR A325
Plain
4"
7 UNC
1 1/8"
F1852 OR A325
Plain
4 1/2"
7 UNC
1 1/8"
F1852 OR A325
Plain
4 1/4"
7 UNC
1 1/8"
F1852 OR A325
Plain
4 3/4"
7 UNC
1 1/8"
F1852 OR A325
Plain
5"
7 UNC
1 1/8"

Tension Control Bolts For Fast Installation And Reliable Steel Connections

Using the appropriate installation tool is also integral to the success of connections in steel construction, and that is no different when installing TC bolts. A sheer wrench, sometimes called a TC gun, is used to secure these bolts in place. This is an electric tool that does not require calibration. Instead, it ensures the bolt is properly calibrated on installation through an internal socket of the wrench. The socket holds the spline of the bolt and enables it to snap off once the proper tension is achieved.

TC bolt regulations advise that bolts are immediately tensioned before installation. Issues can occur when tensioning is completed after the preinstallation process, including problems with lubrication, which can then compromise the reliability of the connection.

Preinstallation testing of TC bolts should always be completed. Once the bolt is installed and the tip has sheared, it’s not possible to fully evaluate whether correct tension has been achieved. Inspection prior to installation will ensure the best possible results and longest lasting performance.

Tension control bolts are available in one of two different types: ASTM: A325 tension control bolts (F1852), in plain or mechanically galvanized, and ASTM: A490 bolts (F2280), which are plain and not available with a coating. These TC bolts are made from high-strength steel and are available in many different diameters and lengths. The diameters we carry range from 5/8" to 1 1/8" in every length manufactured up to 8 1/2" long.

A325 Tension Control (TC) Bolts Quality And Performance Considerations

A325 tension control bolts and A490 tension control bolts perform optimally in a moderate temperature range: between 40° F and 90° F. Galvanized tension controls bolts are an excellent choice for outdoor or exposed installations, or where corrosion or weathering is a concern. Plain, uncoated TC bolts are suitable for indoor or enclosed installations, or where exposure to corrosive factors is not an issue.

Why Use Tension Control (TC) Bolts Instead Of Hex Head Bolts Or Rivets?

While rivets were the first fasteners used in heavy construction, other high-strength fasteners were developed that enabled faster installation and required the use of much fewer hex head bolts than rivets.

This was a direct result of hex bolts' superior strength and quicker installation time, which soon prompted the construction industry to use hex head bolts as a standard. While hex head bolts and control bolts share the same component specs, TC bolts are even faster to install, allowing for three to four times greater speed of installation.

Why Source Tension Control (TC) Bolts From Baco Enterprises?

It can be easy to mistake TC bolts as general-purpose, one-size-fits-all fasteners, but choosing the right product, in terms of size, finish, and other factors, is paramount to the success of any installation. The supplier of these bolts is also a major factor in getting the job done efficiently and to the highest standards. Baco Enterprises is proud to offer an expansive selection of TC bolts that meet with the toughest performance and integrity standards.

For twenty years, we have been a major distributor of tension control bolts and are proud to represent leading domestic and international fastener manufacturers. As part of our own quality control measures, we check random lots of A325 and A490 structural bolts to assure each component meets with specific tolerance requirements and integrity standards.

We complete Skidmore bolt testing. During this process, a bolt, nut, and washer assembly is placed in calibrated tension reading equipment. The bolt is then tightened in the exact same way it would be upon being installed in a steel connection. Tightening continues until the spline shears off. At that point, a tension reading is taken to assure the minimum and maximum tension requirements for that bolt's diameter are met.


What You Can Expect From BACO Enterprises

Baco Enterprises’ tension control bolts are always accessible for immediate shipment in every available size and finish, from all manufacturers and origins, and at multiple price points. As with all of our products, tension control bolts are competitively priced and shipment will accommodate your schedule.

Our entire inventory of TC bolts facilitates compliance with AISC and RCSC regulations. We can meet the needs of construction professionals working on projects ranging from small-scale updates and additions to building of major structures.

Our sales and service team can provide guidance on selecting the most suitable type of bolts for your needs and can assist you in identifying the right choice of product from our vast selection.

Steel fabricators and erectors can find common sizes of bolts just about anywhere, but when you purchase from Baco, you can trust that every possible size of TC bolt, as well as timber bolts, anchor bolts, or any other fastener you may need, will be readily available.

We can also provide an unbeatable bolt quality guarantee and are proud to offer on-site support and inspection services. While many vendors come to us to obtain their resale stock, when you work directly with us, you get bolts from a trusted and quality committed source.

You can trust us to meet your tension control bolt needs with reliability and impeccable speed. We are based in NY and maintain one of the most impressive delivery fleets in the region. This enables us to offer some of the fastest shipping to our customers throughout the Northeast and Mid-Atlantic, including New York, New Jersey, Connecticut, Pennsylvania, Massachusetts, Rhode Island, Maryland, Delaware, New Hampshire, Maine, and Vermont.