[R-390] Weird looking set screws

Jacques Fortin jacques.f at videotron.ca
Tue Jun 16 13:13:51 EDT 2026


Hi Fred,
IF EVER you found a valid source for the Bristol ones, let us know !
Allen head ones are more easy to find...
Use the largest head recess size (3/32").
But resist the temptation to buy the Stainless Steel ones: these are less
"tough" than the black oxide coated steel ones...
And for the square nuts... I already "made" some from standard 1/4" hex
nuts.
File or grind those on three sides. I prefer brass to the steel ones
however...

73, Jacques, VE2JFE in Montreal

Aha!  I'm looking for six to ten of the 4-40 x 1/2 inch Bristol socket head
cap screws for the BFO and BW shaft clamps.  One square nut (if available)
would be helpful as well.  If not, I'm sure there would be Allen head screws
at my local hardware store. 
But What didn't work for the ham I got his from was a mix of slotted and
Phillips screws -- the heads wore out quickly. 
-Fred



More information about the R-390 mailing list