Is it possible to put threads on rebar?

The answer is yes, however, there are several issues to consider to avoid liability. For this discussion, we will assume a requirement for threaded rebar as follows:

What is rebar?

Rebar is another way to say "reinforcing bar" and regularly utilized as a part of the concrete establishments to reinforce the concrete. It is held set up by efficient edges or distortions in its surface that enable the concrete to “grip” the bar superior to plain round bar. These deformations are an awesome resource in the masonry applications, yet obstruct the helpfulness of rebar as a threaded fastener.

Rebar Thread Cutting

Why can’t you just put threads on rebar? Rebar cannot simply be cut threaded to the nominal diameter. This is due to the diameter difference between the major diameter of UNC threads and the diameter inside the deformations. The diameter inside the deformations is less than the minimum allowable major thread diameter. This will lead to incomplete threads and the liability that comes with product not meeting dimensional tolerances. As an example, the diameter on rebar between the deformations is .960 and the minimum allowed major diameter on 1″ threads is .9755.

How to properly cut thread with rebar threading machine

The only way to correctly thread rebar is by turning down, or milling the end of the rod so that it is the proper size and shape to be threaded. This is done by removing the outer layer of the bar until the diameter is equal to the deepest deformation on the bar, leaving a smooth surface to thread. The smaller diameter of the threaded portion means that a larger size of rebar will have to be used and turned down in order to have threads that are the correct nominal diameter. If we go back to our example rebar above, we would need to use #9 rebar, instead of #8 in order to have proper 1″ UNC threads.

Things to keep in mind when ordering rebar threading machine

In cases where plans to order rebar threading machine, it is essential that the engineer or detailer specify the diameter of thread needed on the bar, since cut threading a rebar will not result in a complete 1″ UNC thread. When thread type is not specified or ambiguous, Portland Bolt makes the assumption that the design requires a 1″ thread and when cut threading, will use a #10 bar to produce a fully functional 1″ – 8 threads per inch Unified National Coarse thread as opposed to cut threading a #8 bar which results in a 3/4″ – 10 thread per inch finished product. Industrial Machinery Corporation offering best quality TMT Bar threading machine.