High quality machine screws - Page 1
Forum section: electronics / projects

author: tszaboo
author_rank: Super Contributor
timestamp: February 14, 2021, 11:43:45 am
content: I've been looking for something odd for some time. So I have a product in mind, that has screws that are visible on the product. And this would be a high end product, user actually has to operate the screw sometimes. Usually (for the industrial products that I make) I don't give a second though to screws, I just use Stainless steel A2 or A4 on the outside of a product, and don't even bother taking a second look at it.I've seen some products, that have a really high-end design, they have machine screws where the text is laser marked and painted. Some, like my headphone, have a tiny torx, and the surface of the screw seems to be machine turned, with a texture. There are intentional machined lines in a tiny M2 screw, and it has a glossy finish, with such attention to details (thx Sennheiser).So what's the source, or search term for these? I've been looking around, looked at almost the entire catalog of Mitsumi, Würth, Fabory and I just don't know what's the search term or grade or finish, that I should use.

author: Distinctly Average
author_rank: Contributor
timestamp: February 14, 2021, 12:19:15 pm
content: Custom machine screws. When you see this kind of screw they are almost always custom made by the likes of KD and many others. You specify the screw, the finish and any markings and they make it. Depending on the fixing you have to order in large numbers so it is not a cheap undertaking. A few years back a company I worked for wanted such an item for a product. We needed about 5000 but had to order 20K.

author: jfiresto
author_rank: Frequent Contributor
timestamp: February 14, 2021, 01:29:57 pm
content: People often use button head screws for removable parts and panels, for example, ISO 7380 for hex and ISO 7380-1 for torx.

author: mon2
author_rank: Frequent Contributor
timestamp: February 14, 2021, 03:16:59 pm
content: Here is the contact details for the screw manufacturer we are using with excellent results and great pricing:David LinVEDALI HARDWARE CO., LTDTel / Fax: 86-769-82601418Email : group@vedalitech.com , chinatophardware@yahoo.comwww.vedali.com,http://vedali.en.alibaba.comSkype : life1010goThe best recommendation here is to find the best looking screw and finish that you like and share this information with David. He will then offer their equivalent clone. Even better if you can send him the sample but catalogs are fine. In the past we crossed a special M2 screw from Tyco that was $0.85 usd each in 1k qty to $0.06usd when we purchased right from China. Dead ringer for the original with no issues to date. This is an exotic screw so others are much cheaper in cost.Due to the low cost of the screws, you may have to work with MOQs like 3k or so but the savings are there.We are sourcing a black finished screw for our aluminum enclosures with a button head that we mount with an allen wrench. Check the online catalogs for laptop and similar security screws. For us, we did not want to pay the high resale price of the Tyco M2 screw used on their vhdci connectors. It is a gorgeous screw but pricey. Available in China at $0.06 usd each.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: February 14, 2021, 03:37:02 pm
content: I detest button head screws on products. Maybe OK if they're large (like Hardinge uses) but the little ones always strip out the hex and have to be slotted to remove. Use Torx or use counterbores and cap screws or use something else, but shallow small button heads are the pits. Even Phillips, with a properly fitting screwdriver, is probably better.

author: tszaboo
author_rank: Super Contributor
timestamp: February 14, 2021, 07:00:38 pm
content: Quote from: Conrad Hoffman on February 14, 2021, 03:37:02 pmHere is my understanding of screws and bolts:Slotted: Do not use, unless it's for a time machine to go back to the 1950s. Worst screw type.Philips: Good screw for furniture, and wood, because the screwdriver shreds the head into pieces if you over-tighten. Not for electronics.Pozidrive: Better Philips, doesnt come out, designed to be driven with torque limited drivers. Not really for electronics.Hex recess: Good overall screws. But there is better.Torx: Supposed to be driven with torque limited driver, or a person with a brain. Top tier.About the cuntersunk vs button head, it is really up to the application.Quote from: Distinctly Average on February 14, 2021, 12:19:15 pmI also believed that. Sennheiser probably buys their own screw. But I've seen them on limited edition product, where they sold 50 of them in total (about 300 screws).

author: tszaboo
author_rank: Super Contributor
timestamp: February 14, 2021, 11:46:44 pm
content: Quote from: Distinctly Average on February 14, 2021, 12:19:15 pmActually, I've found a closeup photo of the screws, and they had the initials of the (product) supplier marked.Meaning that they are in fact custom.

author: wizard69
author_rank: Super Contributor
timestamp: February 15, 2021, 09:04:07 am
content: There are people about that do in fact machine screws and will actually machine in the torx socket on a mill. This is no a cheap solution by any means. The normal construction method is to forge the heads in a press or heading machine.in any event the thing that caught my attention here is that you expect the customer to be addressing the screws form time to time. If so you need to seriously consider if using screws that require odd tools is even a good idea. The first problem is that customers will loose anything that is not captive. The second is that most screws will wear rather quickly around the heads and before you know it the heads are stripped out. These issues can lead to customer dissatisfaction. If these are for access panels I'd go with some sort of captive latch. One company that has an endless range is SouthCo and they do have a large selection of thumb operated nuts and screws. Southco is just one of a few companies focused on this market.Since you didn't mention what exactly the screws are to do you may want to consider alternatives. For example ball lock pins :https://www.carrlane.com/product/alignment-pins/ball-lock-pinsfrom CarrLane and others.Places like McMasterCarr have a huge selection of screws some that would be considered nicely finished. Also consider the electronic suppliers but look in the panel hardware sections not the hardware sections. The makers of panel products for 19" racks and so forth will likely have some nice looking screws.

author: tszaboo
author_rank: Super Contributor
timestamp: February 15, 2021, 09:47:27 am
content: Yes, I probably should've given some idea about sizes. Much smaller. Between M2x4mm to M4x6mm.By operating, I mean disassembling it to change internal components, maybe 1-2x the lifetime of the device.This is a hobby for people, so using tools is acceptable.

author: ajb
author_rank: Super Contributor
timestamp: February 15, 2021, 04:55:28 pm
content: Most screws have their threads formed by rolling and heads formed by stamping, which is really only suited for high volume production and always exhibits a certain amount of dimensional variance and a certain class of surface finishes. Custom machined screws used to be the domain of the aptly-named "screw machines", which are mechanically-automated lathes, programmed by creating specifically-shaped cam wheels that actuate various machining operations. They take some real craft to get set up, but once that's done it's real cheap to crank out parts. Some shops still run them, but I think a lot of that work has probably moved to swiss lathes, or modern CNC screw machines, which are more expensive, probably not any easier or faster to set up because they're challenging to program and pack a lot of tools into a small machine volume, but vastly more capable and probably faster when programmed properly. With live milling tools and a subspindle they can easily mill torx patterns or engrave text or create basically any feature you could want in a screw.Any kind of custom screw is going to have a substantial setup cost, so there's going to be an effective MOQ even if not an explicit one because the unit price is going to drop precipitously as you amortize the setup over more parts. There are lots of shops out there that do this sort of work, so it may be worth sending out some sketches or example part numbers to a few shops (domestic or overseas) and see what they say.

author: wizard69
author_rank: Super Contributor
timestamp: February 15, 2021, 05:13:27 pm
content: If that is the case standard stainless steel socket head cap screws might be the best approach. The quality of suppliers vary a lot but they will look nice and last through several disassemblies and reassemblies. Standard cap screws will be cheaper than fancy thumb screws. Frankly there is less involved in implementing them too, as captive thumb screws require a separate mounting step. Finally wrenches are dirt cheap and easy to find.The only qualification is that you really don't want to run stainless into stainless. Stainless against stainless often results in galling or seizing which leads to really bad customer experiences.Quote from: NANDBlog on February 15, 2021, 09:47:27 am

author: tszaboo
author_rank: Super Contributor
timestamp: February 15, 2021, 10:36:53 pm
content: http://www.inoxbolt.co.uk/zen/index.php?main_page=page&id=12Not exactly what I was looking for, but it is still interesting.QuoteQuote

author: thermistor-guy
author_rank: Frequent Contributor
timestamp: February 16, 2021, 05:51:13 am
content: Quote from: wizard69 on February 15, 2021, 05:13:27 pmThat is very interesting. I'm new to this whole area (practical tribology).What about using a low-strength Loctite on stainless steel fasteners. Would that reduce galling?

author: wizard69
author_rank: Super Contributor
timestamp: February 17, 2021, 12:08:55 pm
content: I'm not an expert on this either so take what I say with a grain of salt. However the company I work for is involved in medical device production and a good part of the entire plant is stainless steel fasteners. Frankly they suck when you are running stainless against stainless. I've seen things like Nylon insert lock nuts seize up on stainless steel studs when there was never any torque applied to them. There doesn't seem to be any rhyme or reason to when galling or seizing will happen.As for Loctite, that is great stuff and in some cases I have tried the Blue stuff. It seems to help but I can't say I have enough experience to offer an opinion. Loctite is often better than many of the so called anti seize compounds will migrate out of the threads. Loctite on the other hand seals the threads and prevents corrosion.In any event the best course of action in my option is to avoid running stainless against dry stainless.Quote from: thermistor-guy on February 16, 2021, 05:51:13 am