Quick Guide to Threaded Rod (Studding)
In the blog we cover; what is threaded rod, uses for threaded rod, types of threaded rod, common threaded rod finishes, common sizes and cutting threaded rod, plus how to connect and install threaded rod.
Threaded rod is referred to on construction sites by a number of different names, such as all-threads, threaded bar, screw rod, stud-bars, threaded studs or just studding, which is the name we use on our website.
What is Threaded Rod
As you can guess from these names threaded rod, are rods that come in various lengths which are typically threaded along their whole length (ie all thread).
Similar in appearance to a hex set screw and available in a wide variety of types, lengths and finishes, threaded rod is one of the most versatile products available for providing a secure fixing and allowing other fixings like nuts, bolts to be fastened to it.
Uses for Threaded Rod
Threaded rods are widely used wherever a fastener of greater length and rigidity than a standard bolt is needed to secure two items together. They can be used to pin / secure wood or metal items together or to give additional strength to structures supported by concrete and other materials. Their threading makes it easy to attach nuts and other fixings to the rod as required.
Threaded rod is therefore perfectly suited for supporting or suspending items from roofs and ceilings such as pipework, cabling and ductwork, making it popular in construction. They can withstand very high levels of pressure and tension hence threaded rods are often used in MEP and HVAC applications to provide a secure fixing for support systems. Available in a wide variety of types, lengths and materials, threaded rod is also used in a number industries for fastening materials such as:
- General construction
- Electrical installation
- Mechanical and plumbing installation
- Heating and ventilation installation
- Plant room maintenance
- Manufacturing, production and processing facilities
- Automotive assembly and repair
- Medical machinery
- Marine applications
Using threaded rod is simple for anyone who has worked with other types of large fixings as it performs much like standard bolts and screws. With the actual method for installing a threaded rod being very similar to that for installing a bolt or screw. Although there are a couple of differences as threaded rods will usually exceed the length of standard bolts and won’t have a head for hammering or driving.
Types of Threaded Rod
There are several types of threaded rod available on the market that will suit different applications and conditions.
Typically, threaded rod will be supplied with a right-hand thread (where a clockwise rotation will tighten). However, it can be supplied with a left-hand thread, for situations where vibration might cause a right-hand thread to loosen.
All thread (or fully threaded) is the most common type of threaded rod found in construction, as the thread allows for full engagement of nuts and other threaded fixings. They can also be embedded into materials, like concrete, as the threading provides good resistance. Other types of threaded rods include; ‘tap-end stud bolts’ and double-end stud bolts. Tap-end studs have unequal threads at each end, while double-end stud bolts have equal thread length at both ends.
Threaded rods will generally have a standard thread although there are fine threaded rods, whose threads are thinner and closer together than the standard (coarser) type. Fine threaded rods have a greater shear strength and tensile, making them less likely to loosen which may be a consideration where installations are subject to vibration.
Common Threaded Rod Finishes
Threaded rods are available in a wide range of finishes such as Bright Zinc Plated Steel, Galvanised Steel, Stainless Steel, Brass, Titanium, Aluminium and Nylon. With the steel options being the most commonly used in construction. One of the reasons why steel threaded rod is often used is that it is easy to work with, strong, reasonably priced and looks good once installed.
Bright Zinc Plated threaded rod is generally used for dry internal applications as it’s cheaper and aesthetically pleasing but only offers a little corrosive resistance provided by its Zinc coating. Galvanised and Stainless Steel threaded rods are better suited for applications where corrosion is more a consideration such as in humid, damp or wet conditions (ie plant rooms or out-doors) as they offer better corrosion resistance, with Stainless Steel offering the greatest resistance.
Threaded Rod Sizes and Cutting
If a specific length stud is required for your project you could choose to cut down the lengths of threaded rod yourself, with the best way being to use a dedicated threaded rod cutter (studding cutter). This will produce a clean, burr-free cut with less time and effort needed than other cutting methods. Plus, they can be used for cutting installed threaded rod in-situ and even for overhead work as they are reasonably lightweight.
Threaded rod can also be cut to length on a mitre or chop saw, provided that a suitable metal cutting disk is installed. Although this method isn’t as straight forward as you think, since threaded rod can be difficult to hold in place (especially if trying to cut multiple lengths) and any movement might damage the thread when cut. Also once cut the edge of the threaded rod will typically need to be chamfered or ground on a griding wheel to remove any rough edges. Any unfinished edges after cutting the threaded rod will hinder the fastening of nuts and other fixings, so the edges need to be smooth with a clean thread to enable easy fastening.
For any threaded rod ends that remain exposed then studding protection caps are an option. These plastic caps cover the end of the threaded rod to prevent sharp edges from being exposed, as well as protecting the thread of the rod from damage.
How to Connect Threaded Rod Lengths
If you need an extended threaded rod length and want to join several threaded rods the simplest way is to use studding connectors and you guessed it like threaded rod itself they also have a number of different names so can also be called; rod couplers, connector bolts, threaded rod end fittings etc. Studding connectors look like elongated nuts and are threaded on the inside which allow for two threaded rods to be inserted about halfway each to provide a secure fixing. Along with studding connectors you can also use studding adapters which have a male and female threads of differing sizes which is handy if you need to increase or reduce the size of your threaded rod for a required fixing.
How to Install Threaded Rod to Ceilings and Walls
Installing threaded rod to walls or ceilings, you may find that the threaded rod or fixing is already in place ie pre-inserted into concrete. If not, you will need to provide a fixing for the threaded rod yourself. There are a number of ways to provide a fixing for threaded rod in concrete, metal decking or purlins.
- Wedge anchors (also known as drop-in anchors / non-drill anchors) they provide a threaded socket for threaded rod in concrete. They are installed using a hand driven setting tool and are commonly used in mechanical, electrical and plumbing applications.
- Rod hangers offer a quick and easy alternative to wedge anchors. They have a self-tapping concrete screw tip at one end and a threaded socket at the other for threaded rod. As there is less drilling and no expansion, they offer several advantages over wedge anchors; they can be drilled straight in, repositioned, create less dust and can be installed closer to edges and in cracked concrete.
- Back plates can be simply fastened to walls and ceilings to provide a fixing for threaded rods for supporting building services.
- Rod hangers / Purlin clips for suspending threaded rod from vertical faces or purlin sections for supporting building services.
- Wedge nuts for use in many common metal decking types, they have a tapped hole for accepting threaded rod. Also known as v nuts due to their shape they simply insert and turn into the channel of the metal deck to provide a fixing.
- Lindapter fixings for use in common metal decking types, these fixings have been designed in conjunction with the specified decking manufacturer to fit the channel of the metal deck and provide a fixing for threaded rod.
Unsure Which Type of Threaded Rod You Need?
If you still have any queries regarding which threaded rod and accessories you need, please contact our team on 01322 274226 or [email protected]. Alternatively, you can check out our threaded rod and accessories range here.