I’m interested to know if anyone can tell me the size of the four screws that attach the alloy dash panel to the steel brackets behind the dash. A past post by Tadek states 4 x 2BA pointed. I’m assuning self-tappers? I particularly want to know the size and style of the slotted screw heads. Are they pan-head, round head, cheese head, etc? As long as the head is the correct look, I may fit appropriate machine screws and rivnuts, as I’m not a great fan of self-tappers. These screws are on show, so I’d like to have the correct look, having seen all manner of incorrect-looking fasteners on other cars.
My notes show the following (probably copied from an earlier topic):
The whole assembly is fixed to the scuttle with 4 set screws C.2015/2 with the slotted head in sight.
Set screw C.2015/2 is a 2BA x 3/4" version, so requires a tapped hole 2BA. So not a self-tapping screw.
Tadek provided the following information:
I compiled a list of all the 2BA Chrome Slotted, oval, countersunk set screws used on the XK120:
|C2015/2||Facia Panel (dashboard)||4||2BA x 3/4’’ P|
|C2015/3||Hood Cloth to Floating Stick||2||2BA x 1’’ F|
|C2015/5||Windshield Hook on centre pillar||3||2BA x 3/8’’ F|
|C2015/6||Casing under scuttle at back||2||2BA x 5/8’’ P|
|C2015/6||Mirror to Scuttle 2||2||2BA x 5/8’’ ?|
|C2015/6||Webbing strip to Rear Stick||2||2BA x 5/8’’ F|
|C2015/9||Windscreen to Side Pillars||2||2BA x ?? F|
|C2015/10||Windscreen to Side Pillars||2||2BA x ?? F|
|P indicates end of the screw is pointed,|
|F indicates end of the screw is flat|
Thanks, Bob. That’s the info I found from Tadek on an earlier thread. I believe the 2BA machine screw heads are raised countersunk (sometimes called “instrument screws”). The washers behind them would of necessity have to countersunk. I remember now that I used cheese head slotted screws into nuts behind the flanges of the locating brackets. I can’t think why I assumed 2BA was a self tapper!!
I’m going to side with Viart (page 458) at least as it pertains to a November 1953 car. Viart states the 2BA setscrews are secured by a nut and shakeproof washer. That’s what I have.
The heads of my setscrews are .395 inch in diameter and appear to be cadmium plated (not chrome). If I were duplicating what they look like, I would start with 10-32, Truss Head, slotted setscrews. Then I would turn the heads down to .395”. No washers under the heads.
Thanks, Mike. So now we have raised countersunk with washer or truss head (we call it mushroom head in the UK). I’m tending towards mushroom head (easier) with rivnuts instead of ordinary nuts. What would be the nearest metric equivalent to 2BA, I wonder? I can hear gasps from the hard-liners, but the head is all that anyone sees, after all…
Chris, 10-32 threads, which are common in the U.S., are nearly the same as 2BA threads. A10-32 setscrew with a Truss Head is something like .44 inch in diameter. So these could be turned down to look exactly like the setscrews on my dash panel.
M5 would be the closest to BA2 (5mm v/s 4.7mm), but there are 2BA with slotted mushroom heads available (and rivetnuts too).
These (correct) BA screws are still available, in particular in the UK. Try searching for:
“2BA raised countersunk slotted screws” or similar and you’ll find them. They are available in chrome or even in stainless (not for the “purists” but after polishing they look OK).
I’ve seen some cars (original?) with a “cup washer” behind the CSK head, which is what Jaguar put under most screws that held leather or vinyl trimmed panels. Cannot find them in any Spare Parts Catalogue, so may be not for these facia panels.
I’ve ordered some stainless M5 raised countersunk slotted 3/4" screws and some matching solid stainless cup washers. The stamped ones commonly available look too rounded on their angles. I like the idea of the screw not turning against the leather, although I know the final tightening can be done via the nuts on the back being turned while a scredriver holds the screw head from turning. I’ll see how they look when I receive them. It may not be the final answer…