Cartridge Mounting Hardware


I recently upgraded my tonearm to the Clearaudio Universal. This is a great arm and worth tweaking and experimenting a bit to get the best out of it. My cartridge – Concerto V2 (7 gr.) – came with several sets of cartridge mounting bolts: 5 mm nylon and aluminum flathead screws, and 8 mm stainless hex bolts. No nuts since my cartridge is tapped for the bolt threads. For years I've been using stainless bolts. With those I use a 49 gr. stainless counterweight and it sits nearly as close as it can go to the fulcrum when VTA is dialed in. When I play the Hi Fi News test record the resonant frequency of the arm is more or less at ~10 Hz as far as I can tell.

Conventional wisdom – AFAIK – says that's all good. 

I recently saw a Clearaudio photo of my arm with another one of their cartridges in the line (also 7 gr.) and it's mounted with the nylon screws. That got me to thinking about trying it, and maybe trying the aluminum ones too. With the nylon screws I can no longer use the 49 gr. stainless counterweight, and have to change to the aluminum 31.5 gr. counterweight, but that sits farther out away from the tonearm fulcrum (although it looks cooler, IMO). I'm trying that now. With the test record the tonearm resonant frequency is still right around 10 Hz. I'm playing music now and don't notice a difference, but my aural memory for such things sucks, so I have to live with it for a bit, and then revert to see how I feel. This weekend I'll play some records I use to test out setup changes and see if I hear anything for better or worse.

So that makes me wonder what others know and experience about cartridge mounting hardware (and techniques). What's your wisdom on the matter?
dwette
At 11:54, "Torque values have nothing to do with sound."

At 3:23, "Of course these things matter. Of course they affect the sound."

Yeah, sure, whatever, Mr. Miller. Goodbye.
While I don’t have the spec for my cartridge’s (Audio-Technica VM540ML) mounting screw torque, I’ve requested that of the manufacturer just recently. If I get an answer back, I’ll share it here. 
I for one do not remember ever seeing an actual torque spec for any cartridge I have ever purchased or investigated the specs of online.
Not saying nobody provides them but not seen it yet.
Now I am not claiming my fingers are an accurate torque wrench at all but every cart I have ever mounted has been by feel and definitely NEVER overtight.
However if you are a bit of a klutz this method may not work very well for you!
You can find a torque table here for various types of metal for small machine screws:  http://www.federalscrewproducts.com/torque-chart.htm 

I don't believe nylon has a torque value as it certainly strips easily.   The torque numbers come from the manufacturers of screws and bolts, as they have ASTM standards for alloys and the materials that make up the screws. 

Note that if one were to apply torque to a screw with a nut on the other end, then the torque applied to the nut also comes into play.  That is, one has to sum the torque applied to the nut and the torque applied to the screw to get the correct total torque.  If the nut doesn't rotate, the cartridge along with the headshell doesn't rotate, then the torque reading on the wrench (or torque screwdriver in this case) would be correct.
I must have a hundred+ small screws left over from cartridges.  Some that came with the cartridge but never fit and I had to use screws from other brands.  Some were too long, some too short, gosh I think I have every material of which small screws were ever made.   In general, I prefer either aluminum, brass, or stainless screws.  I have used nylon but only as a last choice.  The screw material the cartridge comes with is my first clue on what to use.

I never torque cartridges, partly because I never owned a small & spiffy torque screw driver and partly because I am happy to just get the dang cartridge aligned without ruining it!  I am sure I would destroy a cartridge sooner or later if I tried to torque them!
@spatialking

That torque chart is qualified with the following statement, and therein lies the rub, as far as I’m concerned.

Keep in mind that this is only an estimated value. It may provide satisfactory performance. Every application needs to be evaluated on its own to determine the optimum torque for each application

I don’t think I want to trust a torque value for a specific bolt unless it comes from the cartridge manufacturer. I for one don’t want to destroy my $3K cartridge and rather err on the side of the bolts being maybe a bit too lose and/or slightly inconsistent between the two. I tighten mine very gingerly, just enough for the cartridge to stay put.