The oldest method of single point thread programming is to calculate each and every motion associated with the threading and write it as an individual block of the program. This method is called block-by-block threading method, or just a block threading method.

Each of the four basic steps occupies one block of program, resulting in the minimum of four blocks per each threading pass. If the gradual pullout from the thread is used for thread cutting, there will be five blocks of program for each threading pass. When cutting coarse threads, threads in hard or exotic materials, even some multi start threads, this method often means quite a long program. The length of the program, difficulty in editing, high possibility of errors, and even small memory capacity of the control system, are the negative sides of using this method.

On the plus side, the programmer has an absolute programming control over the thread. Such control placed into capable hands can often be applied to some special threading techniques, for example, cutting a thread shape with a threading tool much smaller than the thread itself or making large knuckle threads with a round grooving tool.

Thread programming method using the block technique for a constant lead thread is available on all CNC lathes that support threading.

The preparatory command for this type of threading is G32. Command G33 may exist on some controls, but G32 is the standard G code for Fanuc and...