The fine thread rods i don't believe are meant for fine tuning.. but the finer threads make it a lot less likely to back out from normal playing, they also feel amazingly smooth when tuning, most of my normal ones feel like turning in gravel after the DW fine threads, i wish all my drums had them now.
From the DW website:
True-Pitch® Tuning Rods
To give drummers even more control over their sound, DW created its patented True-Pitch® rod system. The rods feature 5mm threads rather than the 12/24 that’s standard on most other drums. To compare, there is 1 thread every 0.8mm on our True-Pitch® rods (about 20% more threads), versus 1 thread every 1.05mm on most other drums.
The result is a more exacting tuning process.
The Finest Drum Tuning System Available Today
Time-tested True Pitch Tuning™ technology has been around for years.
The added thread count gives drummers an expanded tuning range and the advancement has been adopted industry-wide. As DW’s team of craftsmen and designers have continued to improve upon bearing edge cutting techniques, counterhoop consistency, and overall shell making, the time has come for even more control over tuning. We proudly present, True Pitch 50™: the new tuning standard. At fifty threads per inch, these upgraded stainless steel tension rods
provide ultra-smooth fine-tuning, allowing for less back-out.
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So we're both right. It is meant for fine tuning (though I don't see a difference compared to standard tension rods), and they won't back out as easily.
I should add that on that DW snare I swapped heads on, once I loosened the rods past the point where they were holding any tension, I still couldn't spin them out quickly. On most snares (at least all the snares I've ever owned), as soon as the rods are loose enough, I can just give the key a quick spin and it will back the rod out most of the way. Usually one or two spins will suffice. But on this snare, the rods would not spin freely, meaning I had to manually twist out every single rod the entire way, then do it all in reverse once I put the new head on. With 10 rods all with 20% more threads, that took significantly longer than usual. In all reality, it probably took me about half an hour to swap out the head and get the new one seated and tuned up. Normally that would take me about 10 minutes. Also, I don't know if all true pitch tension rods behave this way, or if this was an anomaly.
Sorry for the thread derail!