Determining and classifying screws and small mechanical parts in a systematic manner?

I have a collection of all kinds of screws and small mechanical parts from photo equipment that I have dismantled or that serve as a spare part supply.



In principle, it is not a bad idea to leave screws and parts in the original holder, as they can then be found quickly for repairs.

However, I would like to set up a filing system for the rest so that they can be stored in an orderly manner.

So how can I organize and identify screws and parts?

I know of self-tapping screws for plastic threads in photo equipment, then ones with a smaller thread pitch for metal. And all of these come in all possible lengths and thicknesses, as slotted and cross-head/JIS.

The small parts have different shapes depending on their origin. For those I can't find any consistent names in the service manuals or only pictures. I therefore also lack clear names for repair reports.

Where can I learn something about this, what technical terms and systems are there?

Andreas Thaler said:

In principle, it is not a bad idea to leave screws and parts in the original holder

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Not sure how to understand this. Leave screws grouped by the camera model they were dismantled from? Or leave purchased screws in the as-bought packaging?

Metal screws I group by diameter; no finer categories. On needs to be aware that the actual diameter --as measured by caliper-- is ~0.05mm less than nominal. Then the confusion about preferred diameters in small sizes. Above 2mm, it's clear: 2.5, 3, 4, 5, 6, 8... But below? Seems that currently the favored diameters are 1, 12, 1.4, 1.6, (1.8). But occasionally I see mention of 1.7. Head shapes: seems that camera designers under constraints to fit complex mechanisms in a small size, did not limit themselves to standard shapes, e.g. DIN. Whatever they need, anything becomes standard if you order 10's of 1000s.

Special items: springs, rods, shouldered screws, I keep in a small ziplok under the name of the original camera, in case, some day...

bernard_L said:

Not sure how to understand this. Leave screws grouped by the camera model they were dismantled from? Or leave purchased screws in the as-bought packaging?

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Sorry, I mean both, screws and parts left in the spare parts camera so they can be found directly and a collection of different parts like in the picture above.

Andreas Thaler said:

So how can I organize and identify screws and parts?

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Hi, I'm not sure exactly what you're looking for. But if I were in the position of having a significant number of random screws that I wanted to organize for ease of finding in the future, I'd probably look for some sort of grid organizing bin. Say from left-to-right for the diameter, then up/down for thread pitch. But I don't know if it's worth the effort.

If it gets more complicated it might be worth going to something like an Excel spreadsheet. If you put all the pertinent info in rows then they could easily be sorted. This would allow using, for example, small zip lock bags with an ID - perhaps an index card inside the bag.

For example, spreadsheet columns might be labeled, camera brand, camera model, part description, perhaps screw diam, screw pitch, screw length, then bag ID#, bag location. So one bag might have, say, 12 parts in it, including screws. So that bag has 12 line entries in the spreadsheet. (This is not hard to do using copy/paste, assuming you are fluent with spreadsheets.) So in the future, if you need some random sized screw, you sort the spreadsheet by: diam, then pitch, then length, and it's easy to see which rows have "possible" hits. Then go to the bag(s) that might work. (The bags can be anywhere you want - perhaps tied to a camera carcass or the third shelf of your gray cabinet, etc.)

I've done a lot of things like this in the past. I always start with a set of sequential numbers in the first column, so I can always re-sort back to the original sequence if desired.

Thank you, sorry, I wasn't clear.

I have three concerns:

1. the identification and classification of screws by type. So for metal, plastic, dimensions, type of screw head, how do you characterize a screw, forms, terms etc. I would like to be able to say more about a screw when I have one in front of me.
2. A clear and unambiguous designation of various mechanical parts in cameras so that I can name them correctly in my reports. There may be a list of definitions for this purpose?
3. And the question of how best to store spare parts. I think it's best to store them in the way they were installed so that they can be quickly identified and found, if possible. So leave a spare camera assembled and don't disassemble it into its individual parts. Only remove what you need at the time.

Regarding screw sizes, I don't know if you have any trouble measuring the pitch. Something I came up with years ago, when I didn't have a thread gauge handy, was to press a bit of paper against the side of the screw (I'm a serious guy, so it's easy to have "dirty" threads that leave darkish lines on the paper). Then lay the paper on a desk, under a precision machinists rule. Use a strong enough loupe to measure between some reasonable number of threads. For example, if you've only got 3 threads, measure and divide by 3.

FWIW I used to try to use a caliper to measure directly on the screw itself, but between trying to balance all together it's easier to measure on the flat paper. If your threads are not dirty enough to mark the paper a strip of aluminum foil will get nice sharp creases (but I'm not sure if pressure of your thumb will stretch the foil into the opening). Something else I've done is to use the same method to measure thread pitch inside of holes. Use a narrow strip of aluminum foil dangling into the hole... perhaps use a toothpick or two to press against the thread. Then measure the aluminum foil under a loupe. Fwiw I use an inch scale Starrett rule graduated in hundredths of an inch, then convert.

As a note, I've seen people here wondering if they've got the pitch exactly right. Using my method, you can calculate what the possible distances would be across the number of threads you have available. Then it's easy (maybe?) under the loupe to see if the "possible" size will fit.

Andreas Thaler said:

So for metal, plastic, dimensions. Type of screw head, how do you characterize a screw, etc. I would like to be able to say more about a screw when I have one in front of me.

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Well, in a spreadsheet it's no problem to add more columns to put whatever description or dimensions you want. Diameter of the head, thickness of the head, type of driver, etc.

Regarding the screw diameter, I might be inclined to have a column for the outside diameter (over top of threads) in addition to the supposed nominal screw size. Just in case you misclassified some unknown size.

FWIW I've dealt with some related sort of things on a larger scale. Where an actual database works much better. But... at some point the databases have been changed and the elaborate setups no longer work. So... data had to be ported over, etc. So my thinking has largely changed, that for smaller systems the spreadsheet, using single line (row) items that can work adequately, can be a good way to go.

Have you looked through various exploded diagrams of cameras? Screws are usually called out. Not certain if actual dimensions and thread style are called out.

If you want to learn about assorted threading types, size specs, etc. I'd go through some web sites that deal with fasteners. I expect that there will be similar sites in Austria. Engineering books, radio controlled model cars, all sorts of palces to learn screw specifications.

As to sorting and classifying, well, it's an issue of what amount of effort is worthwhile. I've worked in a few small scale manufacturing setups, and almost every attempt to sort and track a variety of small items falls apart over time unless there is one or more people devoted to maintaining the system. For camera parts, it's best to keep parts binned based on camera models, or at least manufacturer. And sorted to the limits of your sanity.

Dan Daniel said:

If you want to learn about assorted threading types, size specs, etc. I'd go through some web sites that deal with fasteners.

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I think it will be hard to beat Machinery's Handbook. But way deeper than normal people will care about.

Dan Daniel said:

As to sorting and classifying, well, it's an issue of what amount of effort is worthwhile

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No doubt about that!

But when the amount of stuff one is dealing with gets beyond one's own memory (happens pretty quick with me) I think something like an Excel spreadsheet can be pretty useful. Assuming that one is already fluent with the basic operations AND knows how to type. Otherwise... probably not worth trying to learn.

Thank you for your expertise!



Here is a table of the screws used in the Minolta Maxxum 9000 AF. There are only codes for them, but no names. This makes communication difficult because otherwise you can only describe the screws as best as you can.

As far as the mechanical parts are concerned, I stick to the names in the service manuals.




Here from the one for the Minolta Maxxum 7000 AF. This is the original name given by the manufacturer and is therefore binding.

But a mechanical engineer might use more precise terms. These here are quite general.

I'm glad I don't have to translate all this into German

I am very interested in precision mechanics, so I am happy to receive any information about it.

In the example of post 10, I’ve noticed that they all tend to have part numbers and the same nomenclature: special screw. To distinguish better, reference to the part the screw is used for might be most useful. Like “Special screw, number 123, for wind spool pawl”, or “Shoulder screw, number 123 for wind spool pawl”.

In that example, all pertinent dimensions are given. Doesn’t much matter what name is assigned other than to allow for a non-engineering name/description.

For storage… 35mm film canister and zip lock bags, marked with a Sharpie.

BrianShaw said:

In the example of post 10, I’ve noticed that they all tend to have part numbers and the same nomenclature: special screw. To distinguish better, reference to the part the screw is used for might be most useful. Like “Special screw, number 123, for wind spool pawl”, or “Shoulder screw, number 123 for wind spool pawl”.

In that example, all pertinent dimensions are given. Doesn’t much matter what name is assigned other than to allow for a non-engineering name/description.

For storage… 35mm film canister and zip lock bags, marked with a Sharpie.

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Thanks!

Bead storage! People working with beads have lots of tricks for keeping small parts sorted. e.g.-


Fishing also makes demands for storing small items.


One thing to think about is that many screws in cameras are off the shelf. Meaning that they aren't manufactured specifically for one spot on one model camera. Threading and sizing will usually be to industry specs. Now a company like Minolta could get special runs made of screws for specific purposes. Like your chart above, with shoulders and such. At which point I bet that they were not model specific most times. There was probably a stock of screws, or screw specs, that designers and engineers would use to solve assorted problems. this might have industry wide parts. Or a manufacturer would have a 'book' of fastener options for engineers to pull off of. They weren't re-inventing the wheel again and again.

Two other points. One, fasteners are often interchangeable across different cameras and manufacturers. Japanese threading is, well, Japanese threading.

Two, fasteners often fall into categories and uses. No one wants 318 specific fasteners to make one camera. they will reuse screws all the time across different mechanisms. AND/OR! they will make certain that screws can only have one use. Rollei is very good about this. You could take all the fasteners from a Rolleiflex, mix them up in a jar, and sort them out very quickly because they used different screws, threading, and heads for different parts of the mechanism. Pay attention to some of this as you work on cameras and you might find making sense and find replacement screws in your spare parts tins gets easier.

+1 for the Machinery's Handbook. It is a wealth of knowledge if you are looking for standardized reference to literally any bolt size, pitch, tolerance etc.

Not sure if they have them for very small sizes, but at my shop I have a wall-hanging thread gauge checker that includes both male and female reference. It was a bit pricey - but I use it multiple times a day, so the time and frustration it saves has paid for itself.

I find keeping parts as close to fully assembled until a specific part is needed provides clarity. But it’s often not the best use of space. Small jewelry or bead containers (as previously suggested) help if parts are dismantled. Curved bottoms in these containers are worth their weight in gold. Trying to fish out small parts with square bottoms can be a chore.

((download the zip, have a look at the pics))

Labelling, new packs of nuts, bolts, washers and springs is a simple task, but measuring, and itemising old recovered parts and fittings won't leave much time for photography.
Better to leave salvaged equipment in snap shut poly bags with the bits that came off it.

Just think of the time taken recording film exposures, places and processing details for your negatives.
It can be as simple or complex as you desire.

Go into any old codgers workshop. Stuff all over the place, but it is surprising that they can quite often go straight to the drawer or box where that sought after part is. No computers or card indexes. Just familiarity with your surroundings.

People that are tidy enough to itemise their possessions do not keep clutter around them. It all goes in the bin.