Thread Chain (Cycle98) - Siemens SINUMERIK 840D sl Operating Manual

Programming technology functions (cycles)
8.2 Rotate
8.2.7

Thread chain (CYCLE98)

Function
With this cycle, you can produce several concatenated cylindrical or tapered threads with a
constant pitch in longitudinal and face machining, all of which can have different thread
pitches.
There may be single or multiple threads. With multiple threads, the individual thread turns
are machined one after the other.
You define a right or left-hand thread by the direction of spindle rotation and the feed
direction.
The infeed is performed automatically with a constant infeed depth or constant cutting cross-
section.
● With a constant infeed depth, the cutting cross-section increases from cut to cut. The
● With a constant cutting cross-section, the cutting pressure remains constant over all
The feedrate override has no effect during traversing blocks with thread. The spindle
override must not be changed during the thread machining.
Interruption of thread cutting
You have the option to interrupt thread cutting (for example if the cutting tool is broken).
1. Press the <CYCLE STOP> key.
2. Replace the tool and press the <CYCLE START> key.
Approach/retraction
1. Approach of the starting point determined in the cycle at the beginning of the run-in path
2. Infeed for roughing according to the defined infeed type.
3. Thread cutting is repeated according to the programmed number of roughing cuts.
4. The finishing allowance is removed in the following step with G33.
5. This cut is repeated according to the number of noncuts.
6. The whole sequence of motions is repeated for each further thread.
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finishing allowance is machined in one cut after roughing.
A constant infeed depth can produce better cutting conditions at small thread depths.
roughing cuts and the infeed depth is reduced.
The tool is retracted from the thread and the spindle is stopped.
The aborted thread cutting is started again with the interrupted cut at the same depth.
for the first thread with G0
Operating Manual, 02/2012, 6FC5398-8CP40-3BA0
Turning