A great history lesson. I love learning this stuff!
Do you deduct pts if the swirl are missing?
I find the judging part of our hobby interesting...
Digs 4 Solutions
On Dec 16, 2010 7:37 AM, "Curt/Nancy Arndt" <firstname.lastname@example.org> wrote:
> FYI, the so called circular depressions on the head, i.e., the four little
> indents around the phillips head slots are there to denote that the screw
> a Unified fastener, 10/32 in this case, versus a British fastener which
> would have been 2BA. They are very close but not interchangeable.
> So while you can find the correct fasteners at your local hardware store,
> don't expect to find then with these markings on the head. Unified British
> fasteners were marked during the 1950's to distinguish them from the older
> British thread forms that were being phased out, e.g., Whitworth (BSF,
> etc.) and British Association (BA).
> On British bolt heads there was an actual circular depression on the heads
> of Unified (UNF, UNC) fasteners. Nuts and studs were also marked to denote
> the difference.
> On Wed, Dec 15, 2010 at 8:03 PM, john spaur <email@example.com>
>> 3/16 x 3/4" according to the parts book (RPP0312) They are 10-32 chromed
>> Phillips oval head screws with a cone point and with circular markings on
>> the head.
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