In addition, if you turn your own screws with an imperial lathe,
make sure that you use a 60° tool, NOT 55°, otherwise, especially
with? small screws, it will easily break.
On 27.07.24 12:28, Pierre-Raymond
Rondelle via groups.io wrote:
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Metric pitches have changed around 1968 / 1968:
Dia??? old pitch ? ??? current pitch
3mm??? 0.6mm??? ??? ??? 0.50mm
3.5mm 0.7mm??? ??? ??? 0.6mm
4mm??? 0.75mm?? ?????? 0.70mm
5mm??? 0.9mm??????????? 0.8mm
above they didn't change.
On 26.07.24 06:57, Johannes via
groups.io wrote:
Thanks for all the tips.
I put a
big "toothpick" into the hole and twisted, and the best I
found was 0,6+ pitch on a ca 3 mm hole, and do to the big .xls
from Kerry , a 1/8 is very close, and it will be tested out
tomorrow. As you can see from the picture, it is a very short
hole. So, 55 or 60 deg is not so important.
There are
some restorations on YouTube , and I will try to contact them
for a picture of the head of the screw.
Johannes
Mexico
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