[R-390] Weird looking set screws

[Edward Zeranski]

Have you looked at McMaster Carr or Granger?  When I was working we bought Bristol/Bristo wrenches from them.  Also do a search for TechniTool in PA.
EdZ KG6UTS

Sent from my iPhone

> On Jun 16, 2026, at 10:28, Renee K6FSB via R-390 <r-390 at mailman.qth.net> wrote:
> 
> might i suggest next best thing to Bristol spline would be torx which are not too difficult to obtain and much less chance of cam-out than allen.
> Renée, K6FSB
> 
> 
>> On 6/16/26 10:13 AM, Jacques Fortin via R-390 wrote:
>> 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
>> 
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