Tension Control Bolts, TC Bolts or A325 and A490

Tension control bolts are available as one of two different types. They are ASTM: A325 TC bolts (F1852), which are available plain or mechanically galvanized, and ASTM: A490 bolts (F2280), which are plain and not available with a coating. All these bolts are made from high strength steel and are available in many different diameters and lengths. We move millions of these bolts every year. Diameters range from ⅝" to 1 ⅛" in every length manufactured up to 8-1/2" long.

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

 

 

What Are The 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 tc 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 Are These Bolts Used Instead Of Past Alternatives, Like Hex Head Bolts Or Rivets?

Rivets were the first fasteners used in heavy construction. As time went on, high strength fasteners were developed which enabled faster installation and required the use of many fewer hex head bolts than rivets, as a result of hex bolts' superior strength and quicker installation time, the construction industry soon transitioned to using hex head bolts as a standard. While hex head bolts and control bolts share the same component specs, tc bolts are faster to install, allowing for three to four times greater speed of installation.

What Are The Installation Benefits?

In addition to providing a speedier installation, these bolts allow for a higher quality installation compared to hex head bolts. Hex head bolts require that both the bolt and nut be held while the fastener assembly is tightened with a torque wrench, however using a torque wrench provides little ability to know if accurate tension is reached. Alternatively, these bolts are installed using a specialized tool called a shear wrench or TC gun that tightens the nut while holding the bolt's spline. The spline shearing off is a tested, visual representation that the the proper tension is achieved. This prevents issues of over tightening or under tightening that could occur when installing hex head bolts. Using this method, a bolt can be installed in just a few seconds as opposed to the roughly thirty seconds it would take to install a hex head bolt.

What Are Common Mistakes To Avoid When Sourcing Tension Control Bolts?

Some customers make the mistake of not considering or misinterpreting how the length of a bolt factors in an installation, and will often purchase bolts that may have the correct diameter but an unsuitable length for their purposes. To avoid this issue, determine the thickness of the steel in which the bolt will be installed. The resulting grip measurement can then be checked on a grip chart to verify the correct bolt length for the installation. You can also let us know the grip measurement of your installation and we will help you determine the proper bolt length.

It's also important to consider whether a domestic or imported source will be a factor in your bolt selection and installation. We offer both options from only trustworthy, high quality bolt manufacturers. Customers commonly misconceive imported bolts as inferior quality. However we fully back every product we sell, regardless of where it's made. Bolt specs are consistent internationally, so all quality and performance standards are true of every bolt we supply, whether made in the U.S. or by our Korean manufacturer.

Why Source From Baco Enterprises?

For twenty years, we have been a major distributor of tension control bolts. We represent leading domestic and imported manufacturers and stand behind their superior quality. 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. Our in-house bolt testing procedures include Skidmore bolt testing, in which the 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 tightened when being installed in a steel connection 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.

We also offer job site inspection services for comprehensive on-site bolt testing prior to installation. This ensures premium quality and diminishes risks of potential bolt failure or improper installation.

Installation Tools Are Available

We provide TC guns (shear wrenches) for the installation of tension control bolts. We offer Tone 61 TC guns for the installation of 5/8", 3/4", 7/8" diameter TC bolts, Tone 91 TC guns for 3/4" bolts, 7/8" bolts, 1" bolts, and Tone 111 TC guns for 1" and 1 1/8" TC bolts. Tone 61 and Tone 111 TC guns will cover most installation needs. The Tone 61 TC gun can be used for most standard TC bolts, and the Tone 111 TC is especially useful for the installation of heavy-duty bolts. The Tone 241, also known as the right angle TC gun, is used to get into tight spaces where the Tone 61 cannot engage the nut and spline. We also offer repair services for the TC guns we sell.

The Advantages Of Working With Baco Enterprises

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 you may need will be readily available through us, competitively priced and ready to ship quickly. 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.

Baco Offers Worldwide Shipping!

We ship worldwide. Although we're well known as a New York based construction component supplier and our products have been in iconic NY structures from Madison Square Garden and The World Trade Center, to Yankee Stadium and JFK International Airport, and the United Nations Buildings our products and long time customers can be found across the globe.