Is it possible to buy an assortment of common screws?

[Steffen]

What caps are that?

[olsenn]

All caps are high current? Do you mean high capacity (aka ultracapacitors)?

[parabuzzle]

What caps are that?

These... (photos attached)

[parabuzzle]

All caps are high current? Do you mean high capacity (aka ultracapacitors)?

Yes, high capacity.

[alm]

That just looks old. 24,000 uF / 25 V isn't exactly an ultracap, you can get that in much smaller packages these days. Looks like sixties or seventies era technology to me.

[parabuzzle]

eh.. for $1 at my local surplus shop.. its still pretty fun to play with.. its just those screws seem to be impossible to find my part of the world..

[parabuzzle]

and that little blue one is a bit newer and has the same size screw holes.

Its a Mallory type CGS 3000MFD 30VDC POS +85C part: 235-8105A

[robrenz]

my guess is 8-32 threads

[IanB]

That just looks old. 24,000 uF / 25 V isn't exactly an ultracap, you can get that in much smaller packages these days. Looks like sixties or seventies era technology to me.

Those are exactly like the capacitors I got from a scrapped mainframe computer power supply in the mid-70's.

They are big and robust and have a very low ESR.

Do modern ones in smaller packages have the same performance?

[tcv]

Wow! I had no clue this thread would generate so much traffic. Admittedly, I put on a flame retardant suit on in case there were any "lulz n00b".

Maybe a better question is: Is there a guide to screw types that not only give the standardized name but also the utility?

[edavid]

What caps are that?

These... (photos attached)

They are called "computer grade capacitors", although that doesn't make sense any more.  The screw thread is 10-32.

[IanB]

Wow! I had no clue this thread would generate so much traffic. Admittedly, I put on a flame retardant suit on in case there were any "lulz n00b".

Maybe a better question is: Is there a guide to screw types that not only give the standardized name but also the utility?

There are many such guides, but the kind of screws you will encounter depends a lot on your location. Have you considered updating your profile so we know where you are in the world?

[andtfoot]

Imagine trying to do the same in most countries outside the US where the local hardware store will only sell metric. Of course tcv helpfully omitted his/her country.

On the contrary, here in Australia I have trouble getting metric anything at the main hardware store chain. Bloody annoying most of the time.
I usually order stuff from a fastener specialist if I can help it.

[AlfBaz]

I've seen a lot of old electrical gear use BA threads though that may be due to our colonial heritage here in Australia

[tcv]

Wow! I had no clue this thread would generate so much traffic. Admittedly, I put on a flame retardant suit on in case there were any "lulz n00b".

Maybe a better question is: Is there a guide to screw types that not only give the standardized name but also the utility?

There are many such guides, but the kind of screws you will encounter depends a lot on your location. Have you considered updating your profile so we know where you are in the world?

Ah, sorry. I've updated. I am in the U.S.

[deth502]

lemme tell you something about the damn metric system.....

everybody's always throwing shit around about how we HAVE to switch to the metric system like the rest of the world. more and more products are switching over to metric fasteners. *** if you look hard, you can find metric fasteners fairly commonly around here, but do you think for the life of you would could find a single damn metric tap and die? and dont even dream about something like a metric drill bit. 


*** side note: lately, i have been seeing a lot of imported machines that apparently are spec'd with imperial fasteners for delivery to the us, but have metric drive heads to be assembled with metric tools. i fail to see how this could have any advantage in production, but there must be something to it.

[IanB]

Ah, sorry. I've updated. I am in the U.S.

OK, then here's your starting point:

http://en.wikipedia.org/wiki/Unified_Thread_Standard

Basically, standard screws have a three measures that matter: diameter, length, and threads per inch.

For instance, if a screw is described as 1", 8/32, then it will be nominally 1 inch long, the diameter will be #8 (one of the standard smaller diameters), and it will have 32 threads per inch.

There are a small number of sizes like 6/32, 8/32 or 10/24 that are commonly found.

Length is less important of course: if a screw is too long you can always cut it shorter. Many electrician's pliers or wire strippers have a screw cutting feature.

[AlfBaz]

and dont even dream about something like a metric drill bit. 

Accessibility to these things is heavily tied in with where you live unfortunately.

My mum, who not unlike me, has a fascination for cool cases and on a whim bought a set of metric drill bits from a local supermarket for like $15

[IanB]

One thing to note about screws that really annoys me. They usually come either with plain slot head drives, or with Phillips drives.

Slot heads are just ugly: they the screwdriver has no grip on the screw, the bit is not self-centering, and the bit will easily cam out if not precisely centered and aligned. The slot head is horrible.

Phillips screws are barely any better. OK, the bit is self centering, and it can hold the screw to some extent, but the damn thing was designed to cam out of the screw head. The wretched screws were designed to be single use, to get churned up with the screwdriver, and to be hard to tighten or undo. Someone patented a deliberately bad design and got everyone to use it! WTF!

So of course, there must be a better alternative, right?

One is the Pozidriv head, but good luck finding any of those in the USA (or screwdrivers to match).

Another is the square recess Robertson design. These have almost no disadvantages in use, but they are also very rare in the USA. You find them most often in wood screws.

[sync]

So of course, there must be a better alternative, right?

Hex and torx.

[dentaku]

Another is the square recess Robertson design. These have almost no disadvantages in use, but they are also very rare in the USA. You find them most often in wood screws.

I love Robertson screws. It's all professionals use  for wood in Canada. You'd be stupid to use Phillips when you have Robertson available at every hardware supplier and the bits are just as common as Phillips.
I could get all political here when it comes to how logical colour coded money and metric is too, but I won't

[senso]

So of course, there must be a better alternative, right?

Hex and torx.

Can get them more easily than slot and philips here 

[PokemonCookies]

For me finding a specific screw is pretty hard and most likely impossible, so I try to save as many as I can. I'll go to Orchard Supply Hardware and buy boxes and bags of all types. I will also order online and get variaty packs for wood, electronics, metal, you name it.

One other thing I do which has bailed me out many a time is collecting broken electronics that people are throwing away, or dumpster diving and collecting the screws and components. Right now I have a pretty extensive collection of screws, through hole, and surface mount components along with a bunch of enclosures, servos, motors and battery housings. I recommend you keep as much useful stuff as you can, within reason.

[tcv]

One is the Pozidriv head, but good luck finding any of those in the USA (or screwdrivers to match).

I found this resource for screw heads that's pretty nice.

http://resources.tannerbolt.com/articles/what-type-of-screw-is-this/

[BravoV]

For US number sizes you can calculate the nominal diameter:
Number x 0.013" + 0.060" = nominal diameter. Example 4-40   4 x 0.013" = 0.052" + 0.060 = 0.112" diameter
The screws will typically measure several thousandths smaller than the nominal.

These are links to Amazon supply since they will ship international. They show 3-4 week before shipping on these items. The website is a little flakey I found that "esc and refresh" will get it moving when it seems to hang.

Robrenz, thanks for pointing those great resources. 

I only need less than 10 each for the screws and nuts, with those 100 per-order, even they're affordable, the international s/h cost to here at my place is about > $50, which is way too much for me. 

Honestly, I'm expecting someone could help me by just sending maybe 5 or 10 pieces of these in envelope and using cheap USPS.