precision tweezers

[lacek]

Hi,
I need tweezers for very fine SMD work, i.e. working on iPhone logic boards. They include lots of fine 01005 elements that are smaller than the tip of the tweezers I use now. I have been browsing catalogues of various manufacturers and they are short on details about how the size of the tips of their producs. For example Weller writes "fine"  or "very fine" without defining how fine is this very fine.

Could someone give me some hits as to which manufacturer to target or any other way of determining how small these tweezers are before I buy them?

[eliocor]

Take a look at some pictures I have made to some really good tweezers:
https://www.eevblog.com/forum/buysellwanted/on-ebay-lindstrom-tweezers/msg57905/#msg57905

[minho]

Personally, I use Hakko/CHP 5SA tweezers. Very good quality and low price. I also work at the 01005 level. I wish they could be a little pointier but these definitely work.

I also ordered these newest tweezers for doing ultra-fine work but mine arrived damaged (from a different supplier who refused to replace them so I won't plug them) 

Look here: https://www.martview.com/products/precision-0-15mm-titanium-alloy-tweezers-phone-motherboard-jump-line-repair-tools

[tooki]

Hi,
I need tweezers for very fine SMD work, i.e. working on iPhone logic boards. They include lots of fine 01005 elements that are smaller than the tip of the tweezers I use now. I have been browsing catalogues of various manufacturers and they are short on details about how the size of the tips of their producs. For example Weller writes "fine"  or "very fine" without defining how fine is this very fine.

Could someone give me some hits as to which manufacturer to target or any other way of determining how small these tweezers are before I buy them?

Look at Wiha, from Germany.

[Someone]

I have been browsing catalogues of various manufacturers and they are short on details about how the size of the tips of their products.

The manufacturers (rather than the distributors who put their name on the product) are usually very explicit on the dimensions of their tip geometries, but not so much detail on the tolerances. There are several long threads on the forum already with examples of various tweezers if you go looking.

[lacek]

hi thank you all for all the answers. I will follow all of your advice is one by one.



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[KL27x]

Regardless of what you buy, I suggest a hone for maintaining them. Anytime you accidentally bend them, they might never come back together exactly right when you straighten them. Some careful shaping will make them better than new.

Any ceramic file will do, but sintered ruby is the bees knees for this kind of thing. It's one of the finest grits, and it's very efficient at material removal relative to the fineness of the finish. (Not that you need speed to shape the end of a tweezer). And it's tougher than white/brown aluminum oxide ceramics, so little slip stone files will be less prone to breaking if you drop them or strain them with pressure. Translucent Arkansas stone is excellent, too, but you will definitely get some wear/scratching/gouging from filing on points of hardened steel.

[Melt-O-Tronic]

Yet another reason I love this site:  Today I learned what a slip stone is and after a small bit of research, I understand how useful one could be to me.    

[subunit]

I have used some very fine #5 watchmakers forceps for microdissection which might be appropriate. A manufacturer like Dumont provides size specs. I am not sure how small you need to go, but their mini #5s are .06mm at the tip:

https://www.dumonttweezers.com/Tweezer/Electronics/35

They have some angled ESD ones that are also .06mm:

https://www.dumonttweezers.com/Tweezer/Electronics/37

[neslekkim]

Regardless of what you buy, I suggest a hone for maintaining them. Anytime you accidentally bend them, they might never come back together exactly right when you straighten them. Some careful shaping will make them better than new.

Any ceramic file will do, but sintered ruby is the bees knees for this kind of thing. It's one of the finest grits, and it's very efficient at material removal relative to the fineness of the finish. (Not that you need speed to shape the end of a tweezer). And it's tougher than white/brown aluminum oxide ceramics, so little slip stone files will be less prone to breaking if you drop them or strain them with pressure. Translucent Arkansas stone is excellent, too, but you will definitely get some wear/scratching/gouging from filing on points of hardened steel.

Any good source of appropriate sized slip stone for this use?

[KL27x]

I have a ridiculous assortment of stone files. It's one of my things.

A rectangular, a rod, and a wedge/edge would cover most things. I suppose I'd start out with a rectangular block or stone, though.

I have one of these, among a few other shapes of sintered ruby:
http://www.ebay.com/itm/10000-3000-Grit-Knife-Razor-Sharpener-Stone-Whetstone-Polishing-Tool-DT-/262548729118?epid=1873802718&hash=item3d211fad1e:g:COsAAOSwi7RZFG48
I separated the agate from the ruby with a chisel and a light tap from a hammer. The agate will probably break. That's ok, because it's not very useful (IMO). That side is finished coarser, which gives you two different effective grits, too. Then I stuck it in slotted handle with hot glue, so I could use it like a file. (You can hot glue sintered ceramics and translucent ark stones; they're kinda like a closed cell foam. This doesn't work on all stones, though; a soft ark is more like an open cell foam and the oil will seep thru and make the glue fail).

[nanofrog]

Additional brands to check out would be:

• Ideal-Tek (ODM for Lindstrom, Bernstein, TDI, and others)
• Erem
• Rubis
• Regina
• VOMM (COO = Germany, ODM for Wiha)
• Viola (COO = Italy, usually rebranded)

Those without a COO listed are all Swiss made, and have the highest tolerances I'm aware of (0.001"). Viola is 0.003"; not quite as good, but still decent.

[neslekkim]

I have a ridiculous assortment of stone files. It's one of my things.

A rectangular, a rod, and a wedge/edge would cover most things. I suppose I'd start out with a rectangular block or stone, though.

I have one of these, among a few other shapes of sintered ruby:
http://www.ebay.com/itm/10000-3000-Grit-Knife-Razor-Sharpener-Stone-Whetstone-Polishing-Tool-DT-/262548729118?epid=1873802718&hash=item3d211fad1e:g:COsAAOSwi7RZFG48
I separated the agate from the ruby with a chisel and a light tap from a hammer. The agate will probably break. That's ok, because it's not very useful (IMO). That side is finished coarser, which gives you two different effective grits, too. Then I stuck it in slotted handle with hot glue, so I could use it like a file. (You can hot glue sintered ceramics and translucent ark stones; they're kinda like a closed cell foam. This doesn't work on all stones, though; a soft ark is more like an open cell foam and the oil will seep thru and make the glue fail).

Thanks, ordered some from ebay to try.
I didn't understand the "sintered ruby" part, but I guess it's syntetic stones, and found that all of them are 3000grit.
Found some sellers that had various shapes of them, so took a kit of that also.

[mrjoda]

i bought KNIPEX 92 34 28 for 7€ in sale ... best tweezers i ever had and they worth any penny. They costs around 15€ but they are excelent.

[KL27x]

Thanks, ordered some from ebay to try.
I didn't understand the "sintered ruby" part, but I guess it's syntetic stones, and found that all of them are 3000grit.
Found some sellers that had various shapes of them, so took a kit of that also.

At the risk of boring people to death:
Ruby is aluminum oxide, but with something else (I forget) added, which gives the red color. It also increases the toughness, in this particular configuration. Sintered ruby is not so difference from your other alumina ceramic abrasives (white or brown, for instance) in construction, but it is signifincantly tougher. They even make it into wheels for rotary power tools. But this also means it can hold a more acute edge (on say a wedge/edge shape) without chipping out.

Sintering is how they make the ruby abrasive. Solid (a single crystal) of ruby would not work. They make tiny crystals of synthetic ruby in a uniform size. (Then they also mix in a specific and very small percentage of crystals that are quite a bit larger in order to make it "pack" into a specific denser arrangement and to induce a calculated assymetry, which greatly increases the toughness). Then the put these loose crystals in a hydraulic press to fuse them together. The pressure makes the crystals fuse at their contact points, but without completely melting together all the way. Like making a snowball. So what you have at the end will always cut. It's shaped like a file, but not just on its surface. It's a file all the way through. (The surface can have features, of its own. So depending on the machined finish it has, it could cut faster; basically it will be a file made of material that is a finer file).

Translucent Arkansas stone is probably the closest natural analogue to this. The technical jargon is that it is metamorphosized "microcrystalline quartz." This basically boils down to diatom shells that have been sintered together. They are pretty close in effective grit, but the sintered ruby cuts a lot faster. This is a very, very fine file. You can sharpen metal to face-shaving edge off it. But for tiny bits of metal like points of a tweezer or tiny rework chisels/Xacto it is not too fine to do some minor shaping (and great for sharpening).

The major downside to the sintered ceramics is they are nearly impossible to grind without a lapping machine. Whatever shape you buy, that is what you're gonna have for the next 100 years of manual use. Takes a long time just to break and smooth over an edge using diamond or silicon carbide.

all of them are 3000grit.

Yes. I figure this happens to be the configuration/combination of crystal shapes/sizes of ruby (which has so far been discovered) which end up with extraordinarily great properties after sintering. Perhaps one day we will discover more useful arrangements and have some sintered emeralds and other stuff, with different properties and grits. FWIW, grits ratings are all very strange. On the Japanese grit rating scale, I figure sintered ruby is probably at least 12K (close to the finest grit artificial sharpening stones made... I think they go up to 16K?). The 3k rating of this ruby is fairly comparable to how we rate sandpaper.

[neslekkim]

I got these today: https://www.ebay.com/itm/391786108873

But they was taped together, and of course with cheap packing tape, so the glue remains on the stones like this:

The bigger one is the one you linked to, got that one earlier, and the tiny ones today, looks nice.

What is the prefered way to remove glue from these, without using something that draws into the stone?, or are these stones so compact that its no issue?, i know from before that various hones should not be used with oil because one destroy them

Edit: Rubbing it off with my thumb was actually easy, I thought the glue was worse than that

[KL27x]

^That is a tempting price.

What is the prefered way to remove glue from these, without using something that draws into the stone?, or are these stones so compact that its no issue?, i know from before that various hones should not be used with oil because one destroy them.

Exactly right. The pores are so tight, it is not an issue. I use these with either oil or water. Often I used them dry and just wash them after the fact (with oil or soapy water). If you want to remove any trace of oil from them, you can easily clean/resurface them with abrasion/scouring. Kitchen scouring powder like Comet/Ajax is commonly used. Or loose silicon carbide grit. But you can also just rub a more friable resin-bonded silicon carbide stone onto them to release some grit. Then rub them together for 10 seconds with a little soapy water.

If you have sticky residue, there's no problem dunking them into acetone. When I separated my combo stone, I left in in a bag of acetone for a few hours to soften up the glue. Follow that with scouring/lapping if needed.

If you want a finer surface, you can finish them with fine silicon carbide grit. If you want a faster lapping surface, you can abrade them against a coarse diamond plate. You can adjust them on the fly as needed, and they will still last beyond forever.

This lapping/scouring thing is something you might do on occasion, just for regular maintenance, anyway. It will reveal (and remove) the new low spots you have made through use. These do wear down, just a tiny bit, when used on steel. For lapping (vs scouring) you want to use silicon carbide grit (and/or a diamond plate for the coarse grinding), because it's harder than alox/ruby. I'm not sure what's in Comet/Ajax. You can buy a whole set of silicon carbide "sticks" in a variety of grits from eBay/china, green in color and maybe 1/2" x 1/4" x 6" in size for under a tenner. These are super friable (not particularly useful for grinding steel, directly) but great for creating lapping paste without buying 1+ lb bags of loose silicon carbide grit.

[neslekkim]

Cool, thanks.
Then I can use my diamond plate again

[KL27x]

Sorry, I'm such a rock nerd. It's hard to contain. I have some small stone files in my garage workshop, at my kitchen sink, and in a cup with my small exacto-style knives and chisels at my electronics workbench. And more days than not, I have one in my pocket.

Re: diamond plate surface treatment of ceramic:
What I like to do is to, is after getting out most of the low spots, rub one side of the stone over a coarse plate in a straight line. Maybe crisscross in two different direction, the idea is to leave distinct score lines, like on a steel file. Even using this bone dry, where the surface quickly turns black, it will continue to cut. I can watch the steel powder falling away and coating my fingers, underneath. Even though I have spent some amount of $$ on a variety of larger bench stones, a small ceramic (or trans ark) file like this does over 90% of my edge maintenance up to and including wood chisels and 8" kitchen knives, and the strop is not always even needed to remove the burr.

The modern Norton translucent ark stones actually come with VERY LARGE machined grooves all over the surface, and they are amazing when new. But even these huge grooves wear away fast compared to the tiny grooves a diamond plate will put in a ruby file. The diamond-rubbed ruby file will cut very fast for something that leaves a razor edge and will require very infrequent (and easy) maintenance.

[neslekkim]

I went crazy for some years ago, straight razors..
And ended up with three DMT hones, one shapton glasscearamic 16000 grit, a selection of belgian coticules, some belgian blues, norton 4k/8k, and a few other stray hones, so yeah, I know a bit about how it feels like.

I learned how to use them on straight razors, which I found to be quite easy, but sharpening other knives, there is my struggle, I could newer use the straight razors due to my hand shaking, but planned to use these hones for my kitchen knives, but have lots to learn there.

These silicon carbide you mentioned earlier? https://www.ebay.com/itm/331722722584

[KL27x]

Yep. Those are bang-on what I have.

I learned how to use them on straight razors, which I found to be quite easy

I have a full hollow straight razor, and I just sharpen it like any other knife. The whole back and forth lapping on a large flat hone is time consuming and unnecessary in my opinion. And the angle it sits on the stone? That's not really working the edge. All you're doing is thinning it and I don't feel like that makes it shave any better. The final apex angle is going to end up very similar to what I put on a kitchen knife, anyway. And you get that apex after the honing, usually. With the stropping. If I were to use a str8, I think I'd buy a full wedge.

Sometimes I shave with a knife. Today it was an 8" Santoku. JC Penney cheap chinese stainless steel. Smooth as anything, but it was a bit too unwieldy to clean up the back of my jawline.

but sharpening other knives, there is my struggle,

FYI, ceramic like these ruby files is a tad slow for initially establishing an edge. If you have hard time to sharpen a knife, maybe it doesn't have a good edge to begin with. For instance, the aforementioned santoku has not touched anything but an ark or a ceramic for years. But to get an edge on it to begin with? I started with a 39 grit belt sander. And it took awhile. The original bevel was approximately 45 degrees...per side, and probably at least half as thick as the spine. And super high in chromium carbides, according to my belt sander.

[neslekkim]

My problem is mostly to hold the correct angle when moving the knive, with the straight, it was easy due to the back to get an correct angle, but maybe it's like you say, that angle that way is not good.
But when I try with normal knives, I tend to round the bevel, and make lot of marks on the knive, so it's mostly due to lack of learning and training i guess.

[KL27x]

with the straight, it was easy due to the back to get an correct angle, but maybe it's like you say, that angle that way is not good.

It's not that the angle isn't "good." It's that unless you use a specific sharpening rock like a coticule, it's not really sharpening the very edge of the razor. It's too acute to do that.

IME, and there are a whole lot of people who will disagree, hardened steel can hold an apex angle of approximately.... 55 degrees. That's the best a good steel can do, if you look REALLY close at the apex. The apex of a well sharpened axe or a straight razor or a microtome blade are all approximately the same, when you look close enough. The axe will shave fine. It might leave an angled "stump" at the base of the hairs, if you really nitpick, because the thickness of the metal behind the apex starts to wedge in the hair and bend it. But in an hour, you won't be able to tell the difference, anyway.

Now when you lap anything, you will not get exact, crispy corners. The leading and trailing edges will get rounded off, period. The rougher/larger the grit, the more rounded the edge is going to be. The more uneven the stone, the more rounded the edge will get. The more loose grit on the surface of the stone, the more rounded the edge will get. So depending on the stone you use, you might get a really good edge even though you're holding an angle of 15 dps per side, forming only a very faint bur, which leaves a great edge with just a couple swipes on a strop (or pulling the burr off with a piece of wood). This is because the stone is rounding the edge just right for what you want to end up with. For this particular tool and steel, anyhow.

The way you sharpen a straight razor, it's like "sharp edge for dummies." You are thinning the edge bevel super thin, but you're usually just thinning the metal behind what is eventually going to be the edge. Then you can't hardly miss to get a good edge on what you have made. If you use a coticule, you might get a perfect edge right off the bat. It just happens to have the grittiness and particle size that can apex a razor, automatically, while honing on the spine. If you use a super hard and fine ceramic which barely rounds the edge, and you just strop lightly a few times, you can get what passes for a well formed apex, but it will fold and crumble away after cutting a few hairs. It's too thin. But if you strop it some more, bang, you get a great edge.* If you use a really rough stone with loose grit, you will over round the edge. But a couple swipes on a fine stone (at higher angle; lifting the spine off the stone), and bang, you have a great edge. Because it's still thin enough to do the biz.

*In lieu of stropping, I will usually just wipe the apex on a smooth bit of ceramic at approximately 25-35ish dps, with barely any pressure, only until the burr is completely gone. This will give an excellent shave and a durable edge. A strop might make it a little better, but at this point it's hard to tell.  This 30ish dps is about the same "burr removal" angle I would use on a knife, axe, str8. It doesn't matter. Cuz.... steel can't hold an edge much finer than that, IMO. Of course, this is with a fine, fine ceramic. As said, the rougher muddier the stone, the more it rounds the edge, so finishing on a rougher stone, the finishing angle will be less. But there are probably 100 million people who think this is plain wrong.

If you don't like scratches and you want an "automatically" sharp edge, by doing same motion over and over again like a robot through a progression of stones, it's hard to mess up with waterstones plus or minus a strop. If you learn to sharpen on dimensionally stable stones, you can maintain and tweak and modify an edge is no time with just a sliver of rock.

I suppose if you looked CLOSE enough, the apex on a knife is pretty much indefinable... just jagged bits and whatnot. To clarify, using the finest and most dimensionally accurate common abrasives (like fine ceramic), the finest angle you can get is somewhere north of 50 degrees. On some steels maybe north of 60. There are finer grits in emulsions/strops and films, but even the plastic 3M films have "give" to them which round the edge, like a strop.

[Gregg]

My problem is mostly to hold the correct angle when moving the knive, with the straight, it was easy due to the back to get an correct angle, but maybe it's like you say, that angle that way is not good.
But when I try with normal knives, I tend to round the bevel, and make lot of marks on the knive, so it's mostly due to lack of learning and training i guess.

Try a WickedEdge sharpening system for knives.  Look at some of the pictures on their forum to see some results from users. 
https://wickededgeusa.com/