Holey Screws?

[randyjaco]

Wow, those little guys are spendy ;$1-3 a piece. Looks like I have a possible Gloat. My $5 purchase is worth about a grand. The problem is that I doubt that there is a big market for these.

Randy

 

[Wreck™Wreck]

In the past they were used as vents in tire molding, holding the identification stamps inside the molds which changed daily. The small whiskers once common on tires in the past are vents to let the air out of the mold features.

On old molded products the heads of screws are often visible around the serial numbers.

 

[Bi11Hudson]

Another possible use might have been as a "banjo bolt" on motorcycles. There is (was) a lubrication system that used them while attached to tubing. The "overbore", or increased size would allow attachment of said tubing. What I remember was drilled crosswise in the head (horizontal) then drilled lengthwise through the fastener. This may be what the intention was, perhaps in R&D work. Just an idea...

 

[ACHiPo]

Wow, those little guys are spendy ;$1-3 a piece. Looks like I have a possible Gloat. My $5 purchase is worth about a grand. The problem is that I doubt that there is a big market for these.

Randy

Use 'em and enjoy! Gloat away!

I can't tell from the picture what material they are, but the ones on the left look like they might be stainless. Stainless vacuum vented screws are typically only used once to prevent galling and seizing (assuming they are screwed into SS). Should be fine for other non-SS applications, but no value for the original use.

By the way the one on the right looks like it's silver plated--likely used in a vacuum RF system.

 

[4GSR]

...........By the way the one on the right looks like it's silver plated--likely used in a vacuum RF system.

That could be a silver ion nitride coating for preventing galling in high torque loading applications, too.