[arfft]

I am looking for the screws as shown in the photograph - the dimension is 3mm x 1,5mm .

Help in finding replacement is appreciated.

It is from an old yashinon m42

Attached Images

 

[Medex]

you can buy cheap helios 44-2. It has at least 3 screws that fix focusing ring

[UncleVanya]

Search for "Set Screws" using the dimensions you have. Or "Grub Screws". You may have to switch to a hex style screw rather than a slotted screw but finding the size shouldn't be hard.

Here's an amazon search for 3x1.5mm set screws:
amazon.com: 3mm x 1.5mm set screw?tag=pentaxforums-20&

(EDIT: The pitch of the screw threads is important too - not sure how you will measure and verify.)

[Not a Number]

Screw sizes are normally given as diameter by length so I take it you mean 1.5 × 3mm. So you want 1.5 × 3mm slotted cone point set screws.

The closest I can find are 1.6 × 3mm slotted cone points. How accurate are your calipers used to measure the diameter?

Buy Slotted Head Cone Point Set / Grub Screws - AccuGroup

This is a manufacturer and they don't do direct sales to end customers however they may be willing to send you samples for free (or for postage):
Cone Point made of Stainless steel (miniature set screws)

Seems to be no choice of thread pitch with this size screws.

[Bob 256]

If you have an ACE hardware store in your neighborhood, chances are they carry something close. In my area they carry both English and metric set screws in small sizes. It's really important to get the thread right. Take your screw along with you and hold it against any candidate. If they mesh smoothly, the threads match. If you have to go on-line, determine the thread pitch ahead of time. Use your calipers to measure 5 thread spaces and divide the value by 5. Measure in both English and metric and one should work for a standard thread value (chances are very high it's metric).

[Medex]

Screw sizes are normally given as diameter by length so I take it you mean 1.5 × 3mm. So you want 1.5 × 3mm slotted cone point set screws.

The closest I can find are 1.6 × 3mm slotted cone points. How accurate are your calipers used to measure the diameter?

Buy Slotted Head Cone Point Set / Grub Screws - AccuGroup

This is a manufacturer and they don't do direct sales to end customers however they may be willing to send you samples for free (or for postage):
Cone Point made of Stainless steel (miniature set screws)

Seems to be no choice of thread pitch with this size screws.

I think the dimension should be 1,6 x 3mm, as you stated.

[arfft]

Thank you for quick feedback. That is very helpful. The measurement wasn't so precise so I may have missed that 0.1mm.

But now I know what I am looking for.

Thanks!

Screw sizes are normally given as diameter by length so I take it you mean 1.5 × 3mm. So you want 1.5 × 3mm slotted cone point set screws.

The closest I can find are 1.6 × 3mm slotted cone points. How accurate are your calipers used to measure the diameter?

Buy Slotted Head Cone Point Set / Grub Screws - AccuGroup

This is a manufacturer and they don't do direct sales to end customers however they may be willing to send you samples for free (or for postage):
Cone Point made of Stainless steel (miniature set screws)

Seems to be no choice of thread pitch with this size screws.

If you have an ACE hardware store in your neighborhood, chances are they carry something close. In my area they carry both English and metric set screws in small sizes. It's really important to get the thread right. Take your screw along with you and hold it against any candidate. If they mesh smoothly, the threads match. If you have to go on-line, determine the thread pitch ahead of time. Use your calipers to measure 5 threads and divide the value by 5. Measure in both English and metric and one should work for a standard thread value (chances are very high it's metric).

Search for "Set Screws" using the dimensions you have. Or "Grub Screws". You may have to switch to a hex style screw rather than a slotted screw but finding the size shouldn't be hard.

Here's an amazon search for 3x1.5mm set screws:
amazon.com: 3mm x 1.5mm set screw?tag=pentaxforums-20&

(EDIT: The pitch of the screw threads is important too - not sure how you will measure and verify.)

you can buy cheap helios 44-2. It has at least 3 screws that fix focusing ring

[aslyfox]

if you ever are looking at working on a Pentax camera or lens you may want to review this thread

Cross-head screws - a caution: - PentaxForums.com

[Qman]

If you have to go on-line, determine the thread pitch ahead of time. Use your calipers to measure 5 threads and divide the value by 5.

If you count the tops of 5 threads then there are 4 spaces between those threads, so you divide by 4. Or, if your first thread is "0", and count to 5, then you would divide by 5.
The standard size is M1.6x0.35, where 0.35mm is the distance from thread to thread. The closest english thread is #0-80, which has an outside diameter of 0.06", or 1.52mm. The pitch of that one is 0.0125", or 0.32mm. So, the two are close in size and you may not be able to measure the differences without the proper tools.

[Bob 256]

If you count the tops of 5 threads then there are 4 spaces between those threads, so you divide by 4. Or, if your first thread is "0", and count to 5, then you would divide by 5............[/url]

My bad. I should have said "thread spaces". Corrected in the previous.

Thanks for catching that.

[Ontarian50]

The responder who suggested a local hardware store might have this size grub screws might be underestimating just how tiny these things are.

I've never seen a hardware store stock anything of the size and precision needed for camera or lens repair. Of course, I've never been in every hardware store in every town.

Still, around my parts only a specialty fasteners supply place would be able to get them - and unfortunately you'd probably have to buy a really large box of them.

I've never had to buy grub screws or other tiny fasteners for my work, because early on I bought scrap cameras and lenses and stripped them down - firstly to figure out how they were constructed, and also to salvage small parts like screws and springs. Keeping all those small parts in little glass jars and pill bottles has really paid off over the years. No matter how weird a stripped screw, I've nearly always been able to find a replacement. There's only about three sizes of grub screw typically found in lenses, although some can be extra long.

If you plan to keep on tinkering with things like the Yashinon in the future, it's a good idea to gather up a few of those cheapo zooms with stuck apertures and cloudy glass, and strip them down for the "gold" inside - those tiny screws, washers and such.