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 bolts and nuts to easily screw or fasten to it.
Threaded rods have many applications, effectively working as a pin to fasten or connect two materials together.
The welded washers 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.
