When it comes to cartridge mounting bolts, the material that really ticks all the boxes is titanium. It’s light, strong and definitely non-magnetic. It’s also on the list of ‘sonically approved’ materials, used in a number of audio applications where mechanical transfer is a key consideration (Nordost’s TC Sort Kones and CH Precision’s 10 Series grounding spikes to name just two). Intrigued by both the potential mechanical and sonic benefits, I decided to give upgrading my cartridge mounting hardware a whirl…
Even a brief search will turn up any number of allen bolts offered in GR2 and GR5 titanium alloy. What’s the difference? GR2 is valued mainly for its outstanding corrosion resistance and the relative ease with which it can be machined. GR5 (or 6Al-4V, its alloy formulation, which will be familiar to cyclists amongst others) is a pig to machine but has four times the tensile strength of GR2, offers up a nice shiny finish and is offers excellent resistance to corrosion. Price-wise there’s precious little to choose between them and neither is going to break the bank. A bag of ten 8mm titanium allen bolts will likely cost you between ten and twenty of whatever currency you are shopping in. You might need to add postage, maybe even a bit of tax and duty, but all in, this is going to be one of your cheaper audio transactions. Given the sheer number of different cartridges I have to mount – and the number of different tonearms I mount them in, I bought bolts in 6mm, 8mm and 10mm lengths, along with matching titanium washers
The bolts themselves are beautifully machined pieces of micro-engineering, with really crisp sockets and clean, smooth-running threads. You can see the difference in the main photo, with the 6 and 8mm titanium bolts at the top, the stainless steel 6mm bolts at the bottom. They even feel quite different to the steel ones, possibly adding some credence to the idea of each material possessing its own particular character. Comparing 8mm stainless steel and titanium examples (the most common length in my experience) the titanium bolts are half the weight of the steel – 0.3g as opposed to 0.6 – yet offer a higher tensile strength: Pretty much a win-win-win.
But there is one major caveat…
Titanium just loves to bind or gall against itself and especially against other materials. Many is the cyclist who will recount a tale of woe involving a titanium sit pin ‘cold welded’ into an aluminium or titanium frame. Given the number of cartridges that employ aluminium alloy, titanium or other metals for their bodies or fixing threads, you need to use an anti-seize compound on any titanium screw threads – at least if you ever want to get them undone again. I use CopaSlip as a matter of course in all metal-to-metal contacts when it comes to audio components. It (or an equivalent) is readily available from eBay or motor accessory stores, or you can use something like Park Tool ASC-1 Anti-Seize compound, available from cycling outlets. A bit like contraception, just make sure you use something!
