Timber Bolts, Including HDG For Wood & Marine Applications
Questions And Answers On Timber Bolts
Why Do Timber Bolts Have Fins?
The underside of the timber bolt’s head includes two or four fins in a parallel position. They are sometimes called nubs.
As the timber bolt is tightened, the fins will grip into the timber. This prevents the bolt from turning, which contributes to the stability of the assembly and the security of the connection.
What Are Timber Bolts?
Timber head bolts are structural-grade fasteners that are used in the fastening of wood-based connections. They are most commonly used in the building of decks, docks, sheds, timber framing, and other structures that require wood-to-wood connections.
Their notable features are a broad, domed-shape head with fins on the underside. They are effective for distributing load and gripping a timber surface.
What Are Timber Bolts Used For?
Timber bolts are used in the fastening of timber-based joints and structures. Common applications include framing for decks, docks, boardwalks, sheds, playground equipment, and similar structures.
They are specifically designed to maintain wood-to-wood connections. They’re economical, tough, and resist corrosion and are used in a wide range of settings for these reasons.
What Are Timber Bolts Made Of?
Domestic timber bolts are manufactured using structural-grade materials. The two most common are stainless steel and carbon steel.
ASTM A037 timber bolts are made from carbon steel, which is usually hot-dipped galvanized to enhance corrosion resistance. Stainless steel timber bolts also offer reliable resistance advantages due to the properties that are inherent to this metal.
What Are Timber Bolt Measurements?
The most important measurements of timber bolts are the diameter and the length, The diameter measurement refers to the thickness of the shaft. The length measurement will include the shaft and threads.
Other measurements that may sometimes be specified are the head diameter and the thread length, which is the length of just the threaded portion.
How Are Timber Bolts Installed?
Timber bolts are installed into pre-drilled holes in timber structural elements. A nut is threaded on to the end of the bolt, and then, using a hex wrench or similar tool, it is tightened in place.
Tightening should be completed until the fins or nubs on the underside of the bolt head grip into the surface of the timber. Sometimes special inserts are also incorporated into the assembly.
Do Timber Bolts Need A Washer?
Timber bolts are not intended to be paired with washers on the head side of the installation. They are made with a broad, domed head that will sufficiently distribute load as the bolt is tightened.
Adding a washer would also interfere with the grip of the fins into the timber’s surface. Washers can still be applied to the nut side of the joint.
Are Timber Bolts And Economy Bolts The Same?
Economy bolts are another way of referring to timber bolts, but both terms refer to the very same type of bolt. The term “economy bolt” is more frequently used in the Pacific Northwest region.
Timber bolts are known by other names as well, including mushroom head bolts, fender head bolts, dome head bolts, and safety head bolts.
Are Timber Bolts And Carriage Bolts The Same?
Timber bolts and carriage bolts are similar but they have distinct features.
Carriage bolts are used to fasten wood to metal. They have a square neck that helps to prevent turning after tightening. Timber bolts are used to connect wood to other wood parts. They also will resist turning but this is accomplished with small nubs on the underside of the head, which grip the material.
Can Timber Bolts Be Used In Pressure-Treated Wood
Timber bolts can be used to fasten pressure-treated wood in various structures. However, these bolts must be made using corrosion-resistant materials like stainless steel or other industrial-grade metals that have been treated with resistance enhancements, such as hot-dipped galvanization.
All other parts of the timber bolt fastener assembly, including any nut or washer, must also be resistant to corrosion when used with pressure-treated wood.