Which screws for this project?

> Note: In order to avoid wasting your time, please be advised that
> welding is not currently an option here. Thanks for your
> understanding.
>
> I like these skates a lot, planning to make slight variations.
>
> http://www.flickr.com/photos/27532210@N04/2565924423/
>
> The aluminum flat bar is 1/16" thick from McMaster. Seems springier
> than Lowe's aluminum and apparently harder so it doesn't clog my
> tools.
>
> After sanding the sides of the skate frame and the wheel fork (the two
> aluminum flat bar pieces), the pieces are coated and Super glued
> together. The wheel ends up precisely aligned.
>
> The skates are taking a beating, that's what they're for. Most of the
> forces are shearing type. Twisting pressure is handled by the
> flexibility of the frame. I have high confidence in the bond,
> otherwise I wouldn't be skating on them (away from cars and with lots
> of protective gear). At the same time, I would like to provide a
> better backup fastening than the single cheap screw currently being
> used.
>
> I would ask about screw placement, but that's probably a fine detail
> that I should determine here. The current single screw is where I
> think the bond is most likely to fail. I'll probably use more screws.
>
> Again, the aluminum flat bar is 1/16" thick.
> The skate frame thickness is somewhere between 1/16 and 1/8". I don't
> know exactly, but I think it's a pretty hard alloy of some type.
>
> Which of these McMaster machine screws would be most nearly
> acceptable?
>
> ... 6-32 or 8-32 Thread
>
> ... Black-Oxide Fnsh Pan Head Phil 18-8 SS
>
> ... 300 SS Pan Head Phil, specifications met... FF-S-92, QQ-P-35, MIL
> 51957, and passivated
>
> Is there a matching nut for a rated screw like that? How important is
> a nut on the other side of the threaded hole? I'll probably use
> superglue to secure the screw.
>
> Thank you.
>
>
>
>
>

> If you are trying to resist shear forces,

> you want the screw as large as
> possible in diameter and you want to avoid having the threaded
> portion in contact with the plates in shear.

> The bolt strength is not going to be terribly important, the
> aluminum has a unknown strength but certainly less than half that
> of the bolt.
>
> My first choice would be a socket head cap screw in black
> phosphate finish but all of those are fully threaded until you get
> to over an inch long.
>
> Using a locking nut (Nylock) would be a good idea in this high
> vibration application.
>
> You didn't ask but I would be looking at using a fairly high
> strength aluminum like 6061-T6

> Note: In order to avoid wasting your time, please be advised that
> welding is not currently an option here. Thanks for your
> understanding.
>
> I like these skates a lot, planning to make slight variations.
>
> http://www.flickr.com/photos/27532210@N04/2565924423/
>
> The aluminum flat bar is 1/16" thick from McMaster. Seems springier
> than Lowe's aluminum and apparently harder so it doesn't clog my
> tools.
>snip<

> John Doe wrote:

>> I like these skates a lot, planning to make slight variations.
>>
>> http://www.flickr.com/photos/27532210@N04/2565924423/
>>
>> The aluminum flat bar is 1/16" thick from McMaster. Seems
>> springier than Lowe's aluminum and apparently harder so it
>> doesn't clog my tools.

> Looking at the picture I would toss the aluminum your using. Get
> some wider material and make a longer piece that can go along the
> sides of the current frame and catch at least one of the existing
> wheel bolts. Maybe even use sheet stock and bend it so that it can
> use the toe area on the shoe as a brace.

> Then on the nose area that you have one screw I would add a
> second. One closer to the top and bottom to spread the clamping
> across the part. That would give you three total hard connection
> points. Screw wise I would use stainless 10-32 and short rivnuts.
>
>
> I would toss the Super Glue. Get some GOOD epoxy and use that.

> With
> the understanding that the failures you will likely see at the
> bonded areas will likely be from aluminum oxide forming under the
> glue.
>
> Or you could just go buy a pair of the inlines that are sold for
> off road use.
> http://1800wwsports.stores.yahoo.net/rolcoyoffroa.html
> Rollerblade Coyote