Is it possible to buy an assortment of common screws? - Page 1
Forum section: electronics / beginners

author: tcv
author_rank: Contributor
timestamp: October 24, 2013, 03:04:31 am
content: This might be just a dumb question, but ... I always seem to be missing screws for things I need to ... uh ... screw. Anyway, how does one buy screws? Are there standard sizes and can one buy an assortment that are used in, say, electronics applications versus other applications?

author: Stonent
author_rank: Super Contributor
timestamp: October 24, 2013, 03:54:04 am
content: Computer screws are fairly standard. The one to hold the cards in are the same size on pretty much all computers. And the ones to hold in a CD-ROM are all the same typically as well.Screws on DB connectors are pretty much standard as well.

author: Monkeh
author_rank: Super Contributor
timestamp: October 24, 2013, 03:55:51 am
content: Quote from: Stonent on October 24, 2013, 03:54:04 am6-32, M3, and 4-40, respectively..

author: c4757p
author_rank: Super Contributor
timestamp: October 24, 2013, 03:59:22 am
content: Quote from: tcv on October 24, 2013, 03:04:31 amWelcome to my world. Try finding a replacement for one of the small Torx screws used in the Tek 2400 series of scopes.

author: EEVblog
author_rank: Unknown
timestamp: October 24, 2013, 04:07:01 am
content: If you search ebay for "screw assortment" you get various kits, but mostly really small stuff for glasses, or wood screws.Or search for "M3 kit" and you get ones like this:http://www.ebay.com.au/itm/STAINLESS-STEEL-SCREWS-M3-M4-BOLT-SCREW-NUT-WASHER-NYLOC-KIT-750pcs-/180974428197?pt=AU_Fasteners&hash=item2a22eaa025&_uhb=1http://www.ebay.com.au/itm/M3-M4-M5-M6-Stainless-Pan-Head-Machine-Screw-Kit-G304-Phillips-Bolt-345-Piece-/300988748057?pt=AU_Fasteners&hash=item461453d119&_uhb=1If you can get a set with M2, M3, M4, and M5, that's a pretty handy set.

author: BravoV
author_rank: Super Contributor
timestamp: October 24, 2013, 04:09:38 am
content: Quote from: c4757p on October 24, 2013, 03:59:22 amSame here, those pesky Tek 24xx screws, have few missing or heavily rusted, and worst I live in metric country, these American's screws or nuts are like those Tek's hybrid ICs, unobtainium.If you managed to find a new replenishment, please, PM me, I need few of them.

author: robrenz
author_rank: Super Contributor
timestamp: October 24, 2013, 04:12:02 am
content: What thread size and head are they?

author: BravoV
author_rank: Super Contributor
timestamp: October 24, 2013, 04:17:25 am
content: Quote from: robrenz on October 24, 2013, 04:12:02 amCan you help ? I will give you the measurement in a day or two, currently I'm on travel.I need this kind of screws and nuts, especially those heavily rusted nuts. Don't know how many wasted varieties of different nuts I've bought at local wasted, they just don't fit.

author: G7PSK
author_rank: Super Contributor
timestamp: October 24, 2013, 07:55:09 am
content: Go to an engineering distributor they should be able to supply what you need you might find that they will not sell less than 10 or 20 of any one item but I have always found that such places will sell 100 bolts for less than the local hardware store sells a packet of 2. I wont buy screws or bolts from a hardware store because of this I would rather have 99 unused screws in stock in a cardboard box than 1 or 2 left over in a silly little plastic bag.

author: fluxcapacitor
author_rank: Frequent Contributor
timestamp: October 24, 2013, 08:49:07 am
content: The nuts/studs/bolts are #4-40 according to this post on electronicspoint :http://www.electronicspoint.com/extending-life-tek-2465-a-t124108.html

author: grego
author_rank: Frequent Contributor
timestamp: October 24, 2013, 11:46:22 am
content: I was beaten to it but they look like standard #40-40s with a torx head.You can pick them up at any Home Depot/Menards/Lowes here in the states. Well the torx head might mean you have to actually look a little bit but the 4-40? No problem. Just need the length.

author: robrenz
author_rank: Super Contributor
timestamp: October 24, 2013, 12:01:08 pm
content: Quote from: BravoV on October 24, 2013, 04:17:25 amFor 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" diameterThe 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.general nut page4-40 toothed washer nut4-40 SS toothed washer nutgeneral Torx screw page4-40 steel screw example4-40 SS screw example

author: c4757p
author_rank: Super Contributor
timestamp: October 24, 2013, 02:06:51 pm
content: Quote from: grego on October 24, 2013, 11:46:22 amI could not find them at all. Every screw they had was too big.... and only a sad, sad handful of Torx, too. Not only that, but I also needed one of the smaller screws that they use in a couple critical spots - even harder to find.And if Menards has them, I really wish we had a Menards...I haven't even heard of them. Looks like they're mostly west of PA (I'm in NY)

author: Unknown
author_rank: Unknown
timestamp: October 24, 2013, 02:13:36 pm
content: 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.

author: Jon Chandler
author_rank: Frequent Contributor
timestamp: October 24, 2013, 02:18:37 pm
content: Hobby stores will frequently have smaller screw sizes but you usually have to go look. There's not a "screw section" per se, but there will be "airplane" screws with the R/C planes, "train screws" with the model trains, etc.

author: robrenz
author_rank: Super Contributor
timestamp: October 24, 2013, 02:19:01 pm
content: Quote from: c4757p on October 24, 2013, 02:06:51 pmYou are in the US so McMasterCarr is your friendtorx screwsstar washer nuts

author: c4757p
author_rank: Super Contributor
timestamp: October 24, 2013, 02:24:06 pm
content: How did I miss them!? Wow, they have atonof stuff. Bookmarked! Thank you.I did eventually manage to find the damn screwssomewhere. A friend just happened to have a couple in a junk bin...

author: senso
author_rank: Frequent Contributor
timestamp: October 24, 2013, 05:20:50 pm
content: Those look like M3 screws will fit just fine, and even round headed umbrako ones would fit just as nice, no need for torx headed ones, only if you want to keep the looks, but umbrako m3's will costo you like 3-4 cents each bolt, plus 1-2 cents nut and washer.....

author: Monkeh
author_rank: Super Contributor
timestamp: October 24, 2013, 05:25:49 pm
content: Quote from: senso on October 24, 2013, 05:20:50 pmReally, you can determine it's an M3 thread without even seeing the thread?

author: senso
author_rank: Frequent Contributor
timestamp: October 24, 2013, 06:16:19 pm
content: I'm saying, replace, nuts AND bolts for metric, not trying to jam metric nuts in imperial bolts.

author: Hideki
author_rank: Frequent Contributor
timestamp: October 24, 2013, 06:36:14 pm
content: The name is actually Unbrako (as in un-breakable), not Umbrako.http://unbrako.com/

author: SeanB
author_rank: Super Contributor
timestamp: October 24, 2013, 06:41:31 pm
content: Funny enough I live in a metric country, but my local bolt supplier does have a selection of imperial sizes in stock, as well as the recoil kits and taps and dies for them. Often the kits are very cheap and I have bought a few over the years as they often are 10% of the cost of the metric ones of similar size ( having been in stock since Pa fell off the bus) and as I often have US made equipment ( parts are made in India but sold as if they were made in the USA though sadly) I do use them regularly.

author: Steffen
author_rank: Regular Contributor
timestamp: October 24, 2013, 07:09:11 pm
content: Assortments of screws can be very complicated and large.There are many types of screws, different materials, different finishes, different sizes (Thinking of M1-M40), different lengths, different heads, with or without stud. It's crazy. If you start to have every possible combination of all criteria mentioned you need a large cabinet with many drawer shelfs inside. (e.g. by raaco). Think ahead, you also want to have washers, nuts and all that stuff.And maybe some imperial stuff like UNC 4-40 SUB-D posts etc.Good that i live in a metric based country.

author: olsenn
author_rank: Frequent Contributor
timestamp: October 24, 2013, 07:27:32 pm
content: No, not possible!

author: parabuzzle
author_rank: Contributor
timestamp: October 24, 2013, 07:37:11 pm
content: I have had quite a time trying to find the screws that go into the high current caps I have at my local hardware store too..-Mike

author: Steffen
author_rank: Regular Contributor
timestamp: October 24, 2013, 07:40:06 pm
content: What caps are that?

author: olsenn
author_rank: Frequent Contributor
timestamp: October 24, 2013, 07:46:06 pm
content: All caps are high current? Do you mean high capacity (aka ultracapacitors)?

author: parabuzzle
author_rank: Contributor
timestamp: October 24, 2013, 07:51:52 pm
content: Quote from: Steffen on October 24, 2013, 07:40:06 pmThese... (photos attached)

author: parabuzzle
author_rank: Contributor
timestamp: October 24, 2013, 07:52:21 pm
content: Quote from: olsenn on October 24, 2013, 07:46:06 pmYes, high capacity.

author: Unknown
author_rank: Unknown
timestamp: October 24, 2013, 08:20:25 pm
content: 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.

author: parabuzzle
author_rank: Contributor
timestamp: October 24, 2013, 08:30:20 pm
content: 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..

author: parabuzzle
author_rank: Contributor
timestamp: October 24, 2013, 08:33:03 pm
content: 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

author: robrenz
author_rank: Super Contributor
timestamp: October 24, 2013, 08:40:08 pm
content: my guess is 8-32 threads

author: IanB
author_rank: Super Contributor
timestamp: October 24, 2013, 09:54:54 pm
content: Quote from: alm on October 24, 2013, 08:20:25 pmThose 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?

author: tcv
author_rank: Contributor
timestamp: October 24, 2013, 09:55:55 pm
content: 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?

author: edavid
author_rank: Super Contributor
timestamp: October 24, 2013, 10:05:41 pm
content: Quote from: parabuzzle on October 24, 2013, 07:51:52 pmThey are called "computer grade capacitors", although that doesn't make sense any more. The screw thread is 10-32.

author: IanB
author_rank: Super Contributor
timestamp: October 24, 2013, 10:24:40 pm
content: Quote from: tcv on October 24, 2013, 09:55:55 pmThere 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?

author: andtfoot
author_rank: Unknown
timestamp: October 24, 2013, 10:29:43 pm
content: Quote from: alm on October 24, 2013, 02:13:36 pmOn 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.

author: AlfBaz
author_rank: Super Contributor
timestamp: October 24, 2013, 10:37:14 pm
content: I've seen a lot of old electrical gear use BA threads though that may be due to our colonial heritage here in Australia

author: tcv
author_rank: Contributor
timestamp: October 24, 2013, 10:44:35 pm
content: Quote from: IanB on October 24, 2013, 10:24:40 pmAh, sorry. I've updated. I am in the U.S.

author: deth502
author_rank: Frequent Contributor
timestamp: October 24, 2013, 10:50:27 pm
content: 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.

author: IanB
author_rank: Super Contributor
timestamp: October 24, 2013, 10:55:10 pm
content: Quote from: tcv on October 24, 2013, 10:44:35 pmOK, then here's your starting point:http://en.wikipedia.org/wiki/Unified_Thread_StandardBasically, 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.

author: AlfBaz
author_rank: Super Contributor
timestamp: October 24, 2013, 10:58:58 pm
content: Quote from: deth502 on October 24, 2013, 10:50:27 pmAccessibility 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

author: IanB
author_rank: Super Contributor
timestamp: October 24, 2013, 11:05:53 pm
content: One thing to note about screws thatreallyannoys 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 wasdesignedto 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.

author: sync
author_rank: Frequent Contributor
timestamp: October 24, 2013, 11:19:13 pm
content: Quote from: IanB on October 24, 2013, 11:05:53 pmHex and torx.

author: dentaku
author_rank: Frequent Contributor
timestamp: October 24, 2013, 11:27:25 pm
content: Quote from: IanB on October 24, 2013, 11:05:53 pmI 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

author: senso
author_rank: Frequent Contributor
timestamp: October 24, 2013, 11:39:49 pm
content: Quote from: sync on October 24, 2013, 11:19:13 pmCan get them more easily than slot and philips here

author: PokemonCookies
author_rank: Newbie
timestamp: October 25, 2013, 12:49:37 am
content: 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.

author: tcv
author_rank: Contributor
timestamp: October 25, 2013, 02:47:52 am
content: Quote from: IanB on October 24, 2013, 11:05:53 pmI found this resource for screw heads that's pretty nice.http://resources.tannerbolt.com/articles/what-type-of-screw-is-this/

author: BravoV
author_rank: Super Contributor
timestamp: October 25, 2013, 01:00:37 pm
content: Quote from: robrenz on October 24, 2013, 12:01:08 pmRobrenz, 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.

author: robrenz
author_rank: Super Contributor
timestamp: October 25, 2013, 02:35:44 pm
content: What size and length are you after?Do you only want torx head?Do you only want the captive star washer style nut?If they are 4-40 then 3mm should fit as it is only .006" larger in diameter and you could replace bolt and nut as others have mentioned with metric I assume you can get.

author: Steffen
author_rank: Regular Contributor
timestamp: October 25, 2013, 03:08:28 pm
content: What? I read it's difficult to get metric screws and prozidriv screw drivers in the "high tech nation" called USA?LOLOkay I agree with the lack of comfort for slotted screws, but with proper tools and philips screws there is much more comfort than you think. Your 100 pieces $5 tool collection will suck anyway with any type of heads. believe me, i made many mistakes by saving money at tools. Bought cheap, bought twice.Torx can also suck with very soft material screws. I was totally pissed off by the aluminium like soft screws inside my Tektronix 2445 Scope that were holding the channel 1 and channel 2 input stage in place. nearly destroyed the Torx recess of the very tight screws. And of course these badass screws have an imperial thread. No replacement available in my collection, but a ton of M3 screws. (Approx. the same size).I think the never ending war "metric vs. imperial system" is getting religious at some point.I have also worked with US American electronic devices few years ago. I had to be very careful not to lose or destroy screws or nuts. Would have been very difficult to find replacements here.For luck the company i work for sometimes specifies the use of metric screws in devices it needs to call for tender international due to financial aspects. Every company offering something else will be omitted! In some areas of electronics design imperial studs, bolts and nuts are still standard (SUB-D bolts, water connections...)The tools for making threads are also not that complicated to get.Just my two cents about that topic by me as someone grown up in the metric system.

author: vk6zgo
author_rank: Super Contributor
timestamp: October 26, 2013, 09:31:46 am
content: Quote from: andtfoot on October 24, 2013, 10:29:43 pmYeah,the big "B" used to have a good selection of Metric screws & bolts,but now they seem to have very few under about 6mm,& a reasonable selection only occurs above 8mm.Mobs of Whitworth,though,very few UNC.The problem with small American screws is that they are not Whitworth,UNC,or UNF,so you are battling to find these "Imperial" sizes.Of course it's the same thing with BA screws.Japanese & German Metric screws of the same diameter used to use different pitches--not sure if that has been sorted out.