Allen screws

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mikenixon
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Allen screws

#1

Post by mikenixon »

Allen screws, or more properly, socket head screws. What about 'em?

These days, having my own shop, I use Allen screws in carburetors and engines occasionally and sparingly. But when carburetors and bikes arrive with them already fitted, it's seldom a good thing. Nine times out of ten they are the wrong length, lack washers, or are overtightened, with the last being the most common by a wide margin.

As with so many things sold by the vampires of the powersports industry -- the patently ignorant and frequently indifferent aftermarket parts suppliers -- Allen screw kits almost universally contain incorrect length screws, demonstrating a distain for the role thread length plays in vulnerable aluminum parts' threads. And, instead of the lockwashers originally found on vintage Keihin carburetors the kits include either plain washers or none at all. Argh!

And carbs equipped with them arrive in my shop always overtightened, so much so that loosening them ("pop") invariably requires the traditional L-shaped "key" wrench, revealing such gross over-torquing of the screws it makes me cringe. The correct tool is a screwdriver type hex driver. It prevents the screw from being torsioned any more than the original Phillips screw would be, and it's a very handy tool besides. Overtightening Allens using any other tool is virtually inevitable, and I can remember many times as a dealer mechanic when I would service a customer's bike and find several examples of pulled threads clinging to "screw kit" Allens that I removed.

These then are the reasons that, though I am on friendly terms with them today, Allen screws did then and continue still to accompany poor workmanship in far too many cases.
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Re: Allen screws

#2

Post by rcmatt007 »

Therein lies the old adage..... tighten it until it breaks and then back off 1/4 turn.

I have found it best (yes I have Allen screws on parts) using the key with the long und in the screw to avoid the temptation to overtighten.
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mikenixon
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Re: Allen screws

#3

Post by mikenixon »

rcmatt007 wrote:I have found it best (yes I have Allen screws on parts) using the key with the long und in the screw to avoid the temptation to overtighten.
Yup. :)
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Re: Allen screws

#4

Post by flyday58 »

I think a lot of the proliferation of these screw kits is that it keeps someone from having to go through the hardware store to try to assemble one yourself, and then when some lengths aren't correct to have to surf online to find them. "Fits 75-79 Gl1000, 79-83 CB750/900/1100/CBX, 53-65 Radio Flyer wagons, all Edsels." Good enough for me!

Good article, well said Mike.
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mikenixon
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Re: Allen screws

#5

Post by mikenixon »

flyday58 wrote:"Fits 75-79 Gl1000, 79-83 CB750/900/1100/CBX, 53-65 Radio Flyer wagons, all Edsels."
:-D
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Re: Allen screws

#6

Post by heraldhamster »

since ya mentioned lockwashers I wanted to throw out & share some possible valuable info on the subject I learned about only a couple of hears ago.

Nord Lock washers

may not be suitable for all applications but they're pretty amazing.
and evidently now available on Bezos-azon...
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mikenixon
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Re: Allen screws

#7

Post by mikenixon »

heraldhamster wrote:since ya mentioned lockwashers I wanted to throw out & share some possible valuable info on the subject I learned about only a couple of hears ago.

Nord Lock washers

may not be suitable for all applications but they're pretty amazing.
and evidently now available on Bezos-azon...
Interesting. I find the stock type plenty adequate though. And probably 1/10 the price! :)
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Re: Allen screws

#8

Post by heraldhamster »

no argument. we use basic split rings all of our parts washers, pumps & industrial heaters.
they are definitely a specialty application part. we use these on fuel and oil strainers for U.S. Navy ships. basically, a lot of stuff that just cannot afford to fail.

I think the design came from aerospace industry. but I could just be blowing smoke on that.
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Re: Allen screws

#9

Post by heraldhamster »

heraldhamster wrote:no argument. we use basic split rings on all of our parts washers, pumps & industrial heaters.
they are definitely a specialty application part. we use these on fuel and oil strainers for U.S. Navy ships. basically, a lot of stuff that just cannot afford to fail.

I think the design came from aerospace industry. but I could just be blowing smoke on that.
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Re: Allen screws

#10

Post by heraldhamster »

oops. am I missing the edit button? all I see are the quotes and obviously not paying attention... sheesh.
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Re: Allen screws

#11

Post by robin1731 »

heraldhamster wrote:oops. am I missing the edit button? all I see are the quotes and obviously not paying attention... sheesh.
What do you want to do? I believe the edit button is only on for a short after posting. Except for mods.
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