How are you dealing with stuck screws?

[Andreas Thaler]

Stuck screws that cannot be removed from their threads are one of the biggest annoyances when repairing photographic equipment. Because you either damage the screw heads when trying to unscrew with force or you have to cancel the repair project.

Screwhead damaged by force


How can you tame such stubborn screws?

Phillips (cross-head) screws in older Japanese devices are almost always JIS standard screws. You should definitely get suitable JIS screwdrivers that do not overtighten the screw heads.

When loosening stuck screws that are secured with adhesive - like bayonet screws in Nikkor lenses - heating, for example with a soldering tip, has proven to be a good solution. The heat loosens the adhesive.

It is also recommended to loosen rusted screws using a screwdriver and hammer.

If the screw head is so damaged that the screwdriver no longer grips, a slot can be milled so that a slotted screwdriver can hold again.

Screws can also be drilled out, which is very difficult with the small screws in photographic devices.

Richard Haw shows in a video how to deal with stubborn bayonet screws in Nikkor lenses:

Repair: Nikon Bayonet Screws (Video)

Hello, Everybody! Spring is here! It is definitely getting warmer and while that is definitely good news, the bad news is hay fever is also rampant! I suffer from it just like many people living he…

richardhaw.com

Richard recommends JIS screwdrivers by Vessel (Japanese brand) which I am also very satisfied with, see

Post in thread 'Minolta x-700 - mirror stuck up, shutter and lover too.'
https://www.photrio.com/forum/threa...-up-shutter-and-lover-too.157160/post-2742565

(No, I do not earn anything from the recommendation

JIS explained:

JIS (Japanese Industrial Standard)

JIS (Japanese Industrial Standard). Does your Phillips screwdriver \"cam-out\" and damage screws? If so, it may NOT be a US Phillips® screw - it may be a Read more

www.vesseltools.com

When a Phillips Is Not a Phillips!

When a Phillips Is Not a Phillips!: Cross-head, Cross-Point, Cruciform, Square Drive Screws and Drivers These screw types have a "+" shaped recess on the head and are driven by a cross-head screwdriver, designed originally for use with mass-production mechanical screwing machines. T…

www.instructables.com

What are your experiences with the topic? How do you get stuck screws out?


+++

All information provided without guarantee and use at your own risk.

 

[xkaes]

You didn't mention Liquid Wrench, etc.

 

[Andreas Thaler]

You didn't mention Liquid Wrench, etc.

Tell us more, please

 

[BrianShaw]

The first thing I do in these situations is not try too much. Too much trying destroys screw heads. If first attempt is difficult, then a bit of penetrating oil or heat. Never a second attempt with more muscle.

 

[Kino]

• If the lens mount is metal, a drop of acetone, wait a few seconds and try.
• If the lens mount is plastic, a drop of alcohol, wait a few second and try.
• Briefly touch the head of a hot soldering iron to the screw and attempt to remove immediately.
• Shock the screw by lightly tapping on the center of the head with a flat punch and a tiny hammer: Do not repeat more than once and attempt removing in between.
• Stripped screw heads: Rotary hobby tool with thin cut-off disc to make new slots.

 

[Kino]

Stuck screws that cannot be removed from their threads are one of the biggest annoyances when repairing photographic equipment. Because you either damage the screw heads when trying to unscrew with force or you have to cancel the repair project.

View attachment 355228

Screwhead damaged by force


How can you tame such stubborn screws?

Most Nikon F Pre and Post AI lenses have threadlock on the screws. Apply a drop of acetone and wait a few minutes. For the above, take a sacrificial flat blade screwdriver, sharpen into a chisel, drive into the screw and try to remove it, but give the acetone time to work.

 

[BobUK]

Do not forget that some screws have LEFT HANDED THREADS.

I have been caught out a few times over the years.

Trying to dismantle a Nikon enlarging lens to remove a spot of dust, I gave up on seeing some sort of thread lock or glue on the threads. Knowing when to desist if possible is a handy skill.

 

[M-88]

Stripped screw heads: Rotary hobby tool with thin cut-off disc to make new slots.

This. And replace with new screws afterwards, of which I have many.

 

[Ian C]

I find that it sometimes helps to use the correct screwdriver blade-only, if you have the kind with removable blades, to insert the blade into the screw head and rap the end of the blade sharply with a small tool-maker’s hammer, or tack hammer, into the screw a number of times, keeping the blows moderate so as to do no damage. Sometimes, the shock transmitted to the screw will break loose the bond between the screw threads.

It can sometimes help to put a miniscule amount of acetone around the screw head. It’s very thin liquid that can seep between the threads and loosen any thread sealer that might have been applied at assembly.

It can also help to introduce a tiny amount of Liquid Wrench, a solvent and oil mixture. The solvent makes the mixture very thin so that it can penetrate between the threads. When the solvent evaporates, it leaves a thin film of oil behind that can make loosening a stuck screw easier.

The one cardinal rule I use whenever working on screws with sockets of any kind is to always apply more axial force into the screw than the rotational torque to prevent slippage that would damage the socket, the tool, or both.

It is essential that the CORRECT tool be used. In the U.S. most folks assume that when confronted with a cross-slot drive socket, that it must be a Phillips socket. But this is wrong. There are several different cross-slot socket designs, each with its own geometry.

Japanese and other Asian made products almost always use the JIS (Japan Institute of Standards) cross sockets. A Phillips tool will “click-clack” as the tool is tested in a JIS screw socket due to the size and shape mismatch. Applying force will damage both the socket and tool.

https://en.wikipedia.org/wiki/List_of_screw_drives

You can also sometimes loosen a frozen cross-slot screw by applying heat. This can be done with an old, Phillips screwdriver worn or damaged beyond use. You’d heat the tool in the flame of a propane torch, and then press it very firmly into the screw socket to transfer the heat. Don't attempt to rotate the screw with the heat-transfer tool. Done with discretion, this is unlikely to damage the lens or camera, since the metal into which the screw is threaded acts as a heat sink, limiting the temperature of the surrounding metal. This might have to be repeated several times to heat the screw sufficiently to cause the screw to break free. Generally, the screw will not become anywhere close the annealing temperature of the screw (which would weaken it).

 

[runswithsizzers]

Tell us more, please

Liquid Wrench is the name brand of a penetrating oil widely sold in the USA. <SDS> I think Liquid Wrench may be better for freeing stuck threads than WD-40 (the other popular penetrating oil in the US). Both tend to evaporate overnight, so if you want a long soak, you may need to make several applications.

Some say <Kroil> is better, if you have that in your country, but I have not tried it.

 

[Kino]

Do not forget that some screws have LEFT HANDED THREADS.

I have been caught out a few times over the years.

Trying to dismantle a Nikon enlarging lens to remove a spot of dust, I gave up on seeing some sort of thread lock or glue on the threads. Knowing when to desist if possible is a handy skill.

That's a good point. I typically try to turn a stuck screw BOTH directions to see if it will budge in either direction. If you can ever get some movement at all, it will eventually back-out...

 

[Sirius Glass]

Once a screw has been chewed up, an "Easy Out" [drilling a hole, and using the left handed thread device] can work the screw out, but then one has to find the proper machine screw to go in. One of the best ways to avoid damaging the Phillips head screw is to have the proper JIS [Japanese] standard screw driver for such screws, so if one is going to work on camera equipment one should have a complete set of the screw drivers.

 

[Andreas Thaler]

Liquid Wrench is the name brand of a penetrating oil widely sold in the USA. <SDS> I think Liquid Wrench may be better for freeing stuck threads than WD-40 (the other popular penetrating oil in the US). Both tend to evaporate overnight, so if you want a long soak, you may need to make several applications.

Some say <Kroil> is better, if you have that in your country, but I have not tried it.

Thanks, I'll see if this is also available in Europe

 

[xkaes]

Once a screw has been chewed up, an "Easy Out" [drilling a hole, and using the left handed thread device] can work the screw out

I've never seen an EASY-OUT small enough to work on photo screws. That would be minuscule. You'd need a magnifying glass to use it.

 

[KerrKid]

There are much better products than Liquid Wrench or even Kroil for freeing up stuck screws. Follow the advice to use acetone or alcohol depending on the situation. The best would be acetone/trans fluid at 50/50 ratio. Trans fluid is slippery stuff and the acetone gets it to where it needs to go.

I like the idea of heating the screw head a bit with a soldering iron. It sounds counter to what you think you should do since heat expands and would seem to make the screw fit even tighter in the female threads that are holding it, but if there is a bonding agent on the screw threads there doesn't seem another logical way to do it.

I think getting JIS tools is great advice and I should have gotten some of these myself long ago.

 

[Kino]

I can highly recommend Vessel JIS Screwdrivers. I bought a variety of them about 5 years ago and they have performed great. The screw often stays on the end of the driver and not just fall off when removed.

They have very reasonably priced sets if you scroll to the bottom of this page:

Screwdriver Sets

Screwdriver Sets. Read more

www.vesseltools.com

 

[KerrKid]

...The screw often stays on the end of the driver and not just fall off when removed.

They have very reasonably priced sets if you scroll to the bottom of this page:

Screwdriver Sets

Screwdriver Sets. Read more

www.vesseltools.com

That is a big deal since often you have to put a screw in vertically and that's when it's likely to fall into a deep abyss.

Thanks for the link.

 

[Laurent]

Thanks, I'll see if this is also available in Europe

In France at least there is Degryp'oil (Degryp coming from dégripper, which means unstucking)

 

[eli griggs]

• If the lens mount is metal, a drop of acetone, wait a few seconds and try.
• If the lens mount is plastic, a drop of alcohol, wait a few second and try.
• Briefly touch the head of a hot soldering iron to the screw and attempt to remove immediately.
• Shock the screw by lightly tapping on the center of the head with a flat punch and a tiny hammer: Do not repeat more than once and attempt removing in between.
• Stripped screw heads: Rotary hobby tool with thin cut-off disc to make new slots.

I don't believe I've ever seen a slotting rotary tool or cutting tool small enough to address a screw this small, flush with the plate it sits in.

If they exist, please put up a link in reply.

 

[eli griggs]

I can highly recommend Vessel JIS Screwdrivers. I bought a variety of them about 5 years ago and they have performed great. The screw often stays on the end of the driver and not just fall off when removed.

They have very reasonably priced sets if you scroll to the bottom of this page:

Screwdriver Sets

Screwdriver Sets. Read more

www.vesseltools.com

I have a mixed, JIS, flat set, of these small drivers and it's great for removing Japanese made camera screws.

For anything with a longer shaft or larger flat head or Philip's, I use both German Wiha and German/Czech Wera drivers, with the Wiha slots 'fatter' than Vessel and Wera flats, which can be an issue, but don't file, grind them down, some slots will require that thick flatness, IMO.

 

[4season]

In the case of a frozen screw in a Salyut-S film back, none of the aforementioned tricks seemed to work, so I ended up drilling out the old screw. Which was a feat, as it was only around 1 mm in diameter. In the past, I've had success using tiny screw extractors (Chinese eBay sellers) but not this time, as there seemed to be corrosion fusing the parts together.

 

[eli griggs]

In the case of a frozen screw in a Salyut-S film back, none of the aforementioned tricks seemed to work, so I ended up drilling out the old screw. Which was a feat, as it was only around 1 mm in diameter. In the past, I've had success using tiny screw extractors (Chinese eBay sellers) but not this time, as there seemed to be corrosion fusing the parts together.

The Harbor Freight set of resharpened micro drills and endmills (the same as on Amazon) has tiny drills/mills that would be suitable for that size screw head, but no coffee or long run before attempting to use it.

A Dremel drill/router base straddle on top of a set of even thickness books or 2" x 4" block of wood which over looks a camera body, secured in place, might be enough substitution of a precise drilling machine, to allow you to slowly lower a micro drill or mill, onto the center of a stuck screw of this size, and bore a hole deep enough that a piece of music wire or other wire, could be epoxied into place, to tork out the screw, after acetone, heat or lube has made free of the camera hole threads.

IMO, I've not tried this yet with my own cameras or electronics and Dremel router.

 

[chuckroast]

Stuck screws that cannot be removed from their threads are one of the biggest annoyances when repairing photographic equipment. Because you either damage the screw heads when trying to unscrew with force or you have to cancel the repair project.

View attachment 355228

Screwhead damaged by force


How can you tame such stubborn screws?

Phillips (cross-head) screws in older Japanese devices are almost always JIS standard screws. You should definitely get suitable JIS screwdrivers that do not overtighten the screw heads.

When loosening stuck screws that are secured with adhesive - like bayonet screws in Nikkor lenses - heating, for example with a soldering tip, has proven to be a good solution. The heat loosens the adhesive.

It is also recommended to loosen rusted screws using a screwdriver and hammer.

If the screw head is so damaged that the screwdriver no longer grips, a slot can be milled so that a slotted screwdriver can hold again.

Screws can also be drilled out, which is very difficult with the small screws in photographic devices.

Richard Haw shows in a video how to deal with stubborn bayonet screws in Nikkor lenses:

Repair: Nikon Bayonet Screws (Video)

Hello, Everybody! Spring is here! It is definitely getting warmer and while that is definitely good news, the bad news is hay fever is also rampant! I suffer from it just like many people living he…

richardhaw.com

Richard recommends JIS screwdrivers by Vessel (Japanese brand) which I am also very satisfied with, see

Post in thread 'Minolta x-700 - mirror stuck up, shutter and lover too.'
https://www.photrio.com/forum/threa...-up-shutter-and-lover-too.157160/post-2742565

(No, I do not earn anything from the recommendation

JIS explained:

JIS (Japanese Industrial Standard)

JIS (Japanese Industrial Standard). Does your Phillips screwdriver \"cam-out\" and damage screws? If so, it may NOT be a US Phillips® screw - it may be a Read more

www.vesseltools.com

When a Phillips Is Not a Phillips!

When a Phillips Is Not a Phillips!: Cross-head, Cross-Point, Cruciform, Square Drive Screws and Drivers These screw types have a "+" shaped recess on the head and are driven by a cross-head screwdriver, designed originally for use with mass-production mechanical screwing machines. T…

www.instructables.com

What are your experiences with the topic? How do you get stuck screws out?


+++

All information provided without guarantee and use at your own risk.

Heat expands and cold contracts. Putting the grumpy mechanism in the freezer for a couple hours is sometimes helps.

 

[mshchem]

Do you need every screw? Can you drill out the head of the screw, that is if all the others come loose?

Why I just take stuff like this to donate or find a friend who wants this stuff. I can repair automobiles, but something this delicate and unknown to me I send it to the shop.

 

[Andreas Thaler]

Do you need every screw?

That's a good point. With five bayonet screws in a lens, four should be enough without misaligning the lens or making it unstable. But it's also a psychological problem. This one screw will never be forgotten

I had overtightened one of the four screws on my Filmomat (film developing device) that fix the cover on the pump when I replaced the impeller. But the remaining three are obviously enough to keep the pump tight.