Threaded Rod – Everything You Need To Know
What is threaded rod?
Threaded rod, often referred to as a stud, is a rod of varying length that is threaded in a helical structure.
Similar in appearance to a screw, the threading extends around and along the rod to cause rotational movements when in use. Threaded rods combine linear and rotational movement to create strong resistance to pressure.
The direction of the rotation caused by a full threaded rod
depends on whether the rod has a right-hand thread, left-hand thread, or both.
Designed to withstand very high levels of pressure and tension, threaded rods are a common fixing for support systems and used for a variety of applications.
What is a threaded rod used for?
Threaded rods are fasteners
and functions thanks to the threading, which causes a tightening action from the rotational movement. Threading on a rod allows other fixings like bolt
s and nut
s to easily screw or fasten to it.
Threaded rods have many applications, effectively working as a pin to fasten or connect two materials together.
Also used to stabilize structures, they can be inserted into various materials like concrete, wood or metal to either temporarily create a steady base during construction or they can be installed permanently.
How to choose the correct threaded rod
There are several types of threaded rod available on the market that will suit different purposes, conditions and materials.
The fully threaded rod that Armafix supplies are usually used when effective grip strength is required through the entire length of the rod.
They are often used to align structures or are embedded into materials, like concrete, as the threading provides good resistance.
The material is another essential factor to consider when choosing the best-suited rod for your application.
Threaded rods are used in a variety of sectors and for several purposes such as construction, plumbing, manufacturing, marine, agricultural, oil extraction and contractor work.
How to cut threaded rod
Sometimes threaded rod will have to be cut to suit your project. It is a common question and not quite as simple as you might think. The rod can be difficult to hold in place and the threading can be affected.
Perhaps the easiest and more efficient way of cutting threaded rod is to use a rod cutter, which will produce a clean, burr-free cut with less effort and less time wasted, plus it is lightweight and can be used for overhead work.
Cutting threaded rod with a hacksaw
If you’re using a hacksaw, a good tip is to take a small block of wood and drill a hole through it to place your rod through.
Secure the rod in the vice with two nuts either side using a thin kerf, the rod can then be cut and held in place. Once it is cut, you can unscrew the nuts, which will tidy up the ends and keep the threading in good shape.
A simple illustration of this can be found here.
Another efficient method is to use a bench vice to hold the rod in place, and an angle grinder to cut the rod. Cut the road at a flat angle and be sure to wait a few minutes before touching the newly cut edge after using an angle grinder as it will be hot.
How to bend threaded rod
As well as cutting threaded rod, sometimes it needs to be bent in order to fit the intended application. This involves using a mounted bench vice and propane or Oxy-Acetylene torch and should be done with caution.
Placing two bolts in the vice again to clamp around the rod, fix the threaded rod securely in place. Apply the lighted torch on the part of the rod you wish to bend.
Metal can be damaged by too much heat, but for stainless steel – as a general rule of thumb – once it is a reddish colour, it is ready to bend. You can reheat the rod several times until you have the required shape.
Remember to use heavy-duty gloves and eye goggles!
How to join threaded rod
If you need to connect threaded rods, you can use connector bolts to get the required length and secure them together.
You can also use threaded rod plastic protection caps to cover and protect the ends.
The welded washer
s are usually there for shear (tension wouldn't require the weld EDIT: IT WOULD REQUIRE THE WASHER, THOUGH). If you have adequate friction resistance or shear keys under the baseplate, you don't need welded washers. If you designed the connection to resist lateral loads through shear in the bolts, it depends. If you designed for 2 of the 6 bolts (I'm guessing at your layout) to take all of the shears, you probably don't need the welded washers as long as your ok with movement of the base of the column equal to the diameter of the oversized hole (again, assuming it's oversized) minus the anchor diameter (Not half, but all - what if the anchor
is slightly off and hard against the opposite side of the hole? There's a reason oversized holes are used in baseplates.) If you need all of the bolts to resist the shear, then you need to have welded washers at all of the bolts. If you don't, you could have a couple bolts closer to the sides of the holes than others, so they'll load first and prevent the others from loading until they have deflected and/or failed - and then the others engage with two fewer than needed and the rest fail.