Wanna see a screw?

[Stuey]

I posted a few e-microscope images of a #2-56 screw over at ToolGuyd. Here's one of them.

This is the Story of a Screw (via ToolGuyd)

The images were taken as quick practice, but I figured I'd share them with you anyways. Please don't think that they're indicative of my technical abilities b/c I can do MUCH better now that I'm more familiar with this scope.

 

[GT89mustang]

Those are pretty cool

 

[pirana]

My brother is going to get one of those scopes for his jewelry business. Which make & model did you get?

 

[Merkava_4]

I'd take that picture along with the screw back to the hardware store and tell the people they need to get a different hardware vendor. Those surface irregularities are unacceptable.

 

[Vinko]

I'd take that picture along with the screw back to the hardware store and tell the people they need to get a different hardware vendor. Those surface irregularities are unacceptable.

These wouldn't be present if you bought Spax fasteners.

 

[Stuey]

My brother is going to get one of those scopes for his jewelry business. Which make & model did you get?

It's a Zeiss electron microscope. I can provide more details if you'd like. An optical microscope would probably be much more useful (not to mention cost effective) for your brother.

 

[Stuey]

I'd take that picture along with the screw back to the hardware store and tell the people they need to get a different hardware vendor. Those surface irregularities are unacceptable.

It's a #2-56 screw, and the irregularities were not noticeable by eye. I bought the packet from Radio Shack about five years ago and first opened it up for this purpose.

These wouldn't be present if you bought Spax fasteners.

I recently bought a packet of Spax wood screws, and they're pretty rough cut at the tip. Although, the overall coating quality is probably a bit more consistent.

 

[Eds_tls]

I'd take that picture along with the screw back to the hardware store and tell the people they need to get a different hardware vendor. Those surface irregularities are unacceptable.

They're fine. I've been a fastener engineer for 13 years and I look at screws for 9 hours a day, 5 days a week. For that small of a part, those threads are very good.

Cool pics by the way

 

[Merkava_4]

They're fine. I've been a fastener engineer for 13 years and I look at screws for 9 hours a day, 5 days a week. For that small of a part, those threads are very good.

Cool pics by the way

I know the screws are fine - I was just seeing if anybody would pick up on my twisted sense of humor.

 

[Eds_tls]

I know the screws are fine - I was just seeing if anybody would pick up on my twisted sense of humor.

gotcha. Sarcasam doesn't translate well on the internet

 

[Stuey]

They're fine. I've been a fastener engineer for 13 years and I look at screws for 9 hours a day, 5 days a week. For that small of a part, those threads are very good.

Cool pics by the way

Thanks!

I hoped you guys would enjoy them.

 

[OccupantRJ]

They're fine. I've been a fastener engineer for 13 years and I look at screws for 9 hours a day, 5 days a week. For that small of a part, those threads are very good.

Cool pics by the way

Would you say that those are rolled threads, or chased? The root radius seems large for a cut thread of that size.

 

[pirana]

It's a Zeiss electron microscope. I can provide more details if you'd like. An optical microscope would probably be much more useful (not to mention cost effective) for your brother.

I was thinking of a digital microscope. Now I realize there is a difference. Gee, where have I heard that before?

 

[Stuey]

I was thinking of a digital microscope. Now I realize there is a difference. Gee, where have I heard that before?

That's okay. I could have also been a bit clearer in the 1st post, so we're equally at fault and if anything me moreso than you.

 

[Eds_tls]

Would you say that those are rolled threads, or chased? The root radius seems large for a cut thread of that size.

Its hard to tell 100% because if there were any tool marks, they're covered by the plating.

But theres a 99.9% chance its rolled. I've never seen any company cut threads on a production basis. Except for big diameter stuff.

Rolled threads are very inexpensive to manufacture, rolling makes for stronger threads, production rate is very high, there is no scrap, and parts are dimensionally very consistant. There's little reason to cut threads unless your making a handfull of prototypes

 

[bushhawg73]

Very nice shot. I took this picture in total darkness with only an ultraviolet light. The fingerprint is mine. It is on a black fingerprint card with green glow in the dark fingerprint powder applied to the print. It was taken with a 8 year old Olympus camera. I was pretty impressed.

 

[OccupantRJ]

Its hard to tell 100% because if there were any tool marks, they're covered by the plating.

But theres a 99.9% chance its rolled. I've never seen any company cut threads on a production basis. Except for big diameter stuff.

Rolled threads are very inexpensive to manufacture, rolling makes for stronger threads, production rate is very high, there is no scrap, and parts are dimensionally very consistant. There's little reason to cut threads unless your making a handfull of prototypes

Unless you have a bunch of old Brown & Sharpe screw machines running geometric die heads, like the company I work for. We roll, chase, and run single point threads, all under one inch. The rolling is done on Davenports, and the single point on Omni-turn GT 75 CNC machines.

 

[MD11]

I posted a few e-microscope images of a #2-56 screw over at ToolGuyd. Here's one of them.

This is the Story of a Screw (via ToolGuyd)

The images were taken as quick practice, but I figured I'd share them with you anyways. Please don't think that they're indicative of my technical abilities b/c I can do MUCH better now that I'm more familiar with this scope.

I thought only universities and governments could afford those.. wow.. Can you link info on the unit? I'm curious what they run?

 

[Eds_tls]

Unless you have a bunch of old Brown & Sharpe screw machines running geometric die heads, like the company I work for. We roll, chase, and run single point threads, all under one inch. The rolling is done on Davenports, and the single point on Omni-turn GT 75 CNC machines.

What size production runs are you doing with the Omni-turns? Why use the those instead of the Davenports? I know they're are pretty slow, but I would still think they're quicker than CNC, no? Unless your doing some funky materials like Inconel???

I only work with screw machines once in a great while. Most everywhere I've worked does cold heading and flat roll dies

 

[alex71]

cool stuff. I wonder how cheap i can get one of those on craigslist?

 

[nate379]

Agreed... reason for...
Merkava_4
This message is hidden because Merkava_4 is on your ignore list.

gotcha. Sarcasam doesn't translate well on the internet

 

[Stuey]

cool stuff. I wonder how cheap i can get one of those on craigslist?

One of what? Electron microscope? I've seen X-ray diffraction equipment on ebay, and there are a few SEMs on ebay too, but for the most part they're junky looking.

 

[FNFS2000]

You need to get some German GRK screws and do a comparo. See what makes those things tick, I can't believe there can be that much difference in something as simple as a screw, but they certainly out engineered the rest.

 

[Stuey]

You need to get some German GRK screws and do a comparo. See what makes those things tick, I can't believe there can be that much difference in something as simple as a screw, but they certainly out engineered the rest.

Maybe someday, but not likely anytime in the near future due to time constraints. There is also the $200 per hour non-contract usage rate to consider as well.

 

[mkdive]

I thought only universities and governments could afford those.. wow.. Can you link info on the unit? I'm curious what they run?

Where you getting seat time on a scope like that stuey? That would be cool! some stuff Im not sure I would come to think of it.

 

[Stuey]

I thought only universities and governments could afford those.. wow.. Can you link info on the unit? I'm curious what they run?

Whoops, sorry about missing your post before.

Certain companies can also usually afford this type of equipment, usually less sophisticated models, but you're right, you won't find any individuals running electron microscopes from their basements. For one thing, it's not like you can just hook up a shop vac to create the proper vacuum levels.

The particular unit I used is a Zeiss field emission scope. Details

Where you getting seat time on a scope like that stuey? That would be cool! some stuff Im not sure I would come to think of it.

I can give you my personal info via PM if you'd like.

It is rather sweet using such equipment, but at times it's not exactly easy. I spent over three and a half hours yesterday examining four specimens, but I also managed to get some chemical analysis out of the session as well.

Due to the high operating costs ($50 per hour legitimate usage, $200 for "outside" or no-contract use) amongst other reasons, I won't be able to examine any objects of personal interest. =(

Maybe when I win the lottery!

 

[redsky49]

I saw the 10 angstrom scale marker in the last pics. How much further, if any, can you magnify, or is that the limit?

 

[OccupantRJ]

What size production runs are you doing with the Omni-turns? Why use the those instead of the Davenports? I know they're are pretty slow, but I would still think they're quicker than CNC, no? Unless your doing some funky materials like Inconel???

I only work with screw machines once in a great while. Most everywhere I've worked does cold heading and flat roll dies

All of our runs are for our own in-house use, so we run what works best for us on each machine, according to volume, setup required, when needed, and other factors. We may be doing 20,000 pcs, or 100 pcs of any given part at any given time.
The Davenports are devoted to long, high volume runs, the B&S for moderate runs, and the CNC for short runs.

 

[benjamming]

Very nice shot. I took this picture in total darkness with only an ultraviolet light. The fingerprint is mine. It is on a black fingerprint card with green glow in the dark fingerprint powder applied to the print. It was taken with a 8 year old Olympus camera. I was pretty impressed.

You might now want your fingerprint all over the web.

 

[mkdive]

You might now want your fingerprint all over the web.

probably true!

 

[Stuey]

I saw the 10 angstrom scale marker in the last pics. How much further, if any, can you magnify, or is that the limit?

That's a micron µm bar. 1 µm = 10,000 angstroms

The screw was giving me some charging issues and is far from flat, which led to a few other issues.

I'm not sure what the resolution is on the scope, nor do I know its maximum magnification under ideal conditions, but I took a decent quality 140,000X image yesterday. If the sample was coated with a conductive film and I bumped the acceleration voltage up a bit, I could have done even better. At that mag, I was able to clearly see features 20nm and smaller.

20nm = 200 angstrom.

If you want to get to a finer scale, you'd have to switch to a TEM - transmitting electron microscope, which is far more difficult to operate than an SEM, but can let you image an actual lattice. Well, not the actual lattice, because you can't actually "see" it, but you can achieve sub-nanometer (10 angstroms or less) resolution.

In a TEM, you can easily achieve a magnification of several hundred thousand times.

For reference, a human blood cell is about 8µm in diamater, and an average hair 100µm.

 

[Stuey]

You might now want your fingerprint all over the web.

He could probably blur out a portion of it, and it'll be fine.