Serge, I looked through your spreadsheet quickly, and would like to comment as follows:
For my 2600 Spider, I just did quite a bit of research into the fasteners attaching the upper and lower A-arms and for attaching the plate that holds the front suspension springs to the lower A-arms. This was triggered by the fact that the threads on several of these bolts were stripped to the point of being dangerous (and an Alfa technical bulletin advising the need for mandatory field upgrades as described below). I could not find any exact replacements for the Alfa parts because of:
(a) the dimensions (e.g. M8x1x42mm for the upper A-arm and M10x1x42mm for the lower A-arm) are not standard length and therefore not readily available (45 mm seems to be the closest standard size),
(b) the bolts are not marked with modern strength classification (i.e. no standard-compliant class or grade marking),
(c) none of the suspension fasteners are listed in the Alfa parts interchange list for standardized parts, and
(d) for the 2600, there was a technical bulletin advising repair shops that the nuts and bolts of the upper A-Arms need to be upgraded to higher strength -- for which they provided only an Alfa parts number. I'm not sure if this TSB applies to 102 cars as well (chances are that the larger 2600 engine and higher speed of 106 cars created much higher lateral forces on the front suspension, which led to bolt stretching Alfa described). Given that the front suspensions of 1900, 2000, and 2600 cars are almost identical, I think it might be a good idea to upgrade the fasteners for the upper A-arms on all of these models.
The closest (and probably safest) components I could get for my front suspension was Class 12.9 hardware (bolts, nuts, washers), but such hardware is not available with 1 mm "extra fine" thread pattern (specifically, no M8x1 or M10x1 Class 12.9 bolts or nuts -- the highest grade for such hardware was 10.9). Class 12.9 seem to be only available in standard thread (1.25 mm for M8 and 1.5 mm for M10) because of the higher pressure and torque values. I ended up buying Class 12.9 with standard thread. I surmise (but I'm not sure) that the difference between standard thread, fine thread and extra fine thread is a trade-off between shear strength (fine-threaded bolts seem to have a thicker cores and therefore higher shear strength than standard threaded bolts) and the axial stretching forces and torque that can be applied to the threads (standard threads can withstand higher forces because they have more contact surface area).
Sourcing Palnuts was an adventure in itself (there is one manufacturer in Italy that makes Palnuts for extra fine threads -- the supply situation for standard thread is much better). For the spring plate, I chose not to use the split lock washer under the nut, as shown in the parts catalog, but to torque it dry to Class 12.9 specs and use a Palnut instead for securing the nut from turning loose.
Like you, I had to buy boxes or bags of 100 pieces each -- even though I needed only 8 for my car. When I'm sure I'm done (I installed the front suspension this weekend and need to double check), I will make my surplus fasteners available to other owners.
With respect to your spreadsheet, including the Alfa Romeo parts numbers for the components (and maybe even what table they came from) would allow much better identification and comparison with what solutions are available.
'63 2600 Touring Spider (AR 191437, the car that started the 2000/2600 International Register, reassembly in progress)
ex-'65 2600 SZ (AR 856043, now being restored in Austria)
Maintainer of a private 2600 SZ register (not the one in the Netherlands).
Last edited by tubut; 09-29-2016 at 01:09 PM.