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Discussion Starter · #1 ·
To all who have shown an interest in this project . . . . .

I contacted a custom manufacturer who called me yesterday, Frdiay, 02-06t. They are perfectly willing to make a run of 2,000 nuts and 2,000 bolts. Remember I was asking for something close to 0.060" across the flats drill and tapped to 00-90 threads.

To begin with they didn't have any 0.060" materials in stock and he told me it would cost "thousands" to get enough material for a run like this. That tipped me off pretty quick . . . . and yes it ticked me off. Brass is high now and I was born during the day but not yesterday. I knew better then that.

The cost to produce 2,000 nuts was quoted to me at $2,000.00 and 2,000 bolts 1/2" long was quoted at $1,500.00. When I told my lovely bride even she saw thru the smoke . . . . they didn't want to mess with it and quoted it so high they knew we woudln't go for it. Of course they were quick to tell me the price per piece would go down with and increased size order and the price of the bolts could go down if the length were shortened to 3/8". By then I was biting my lip so I didn't press for anything further.

Their price for stock 00-90 hex nuts and bolts runs about $200.00 for an order of 2,000.00 pieces. I have little doubt they run their products on CNC and it does take some time to develop a program, but not $1,800 dollars worth of time.

Seve C. suggested I try Antrin Miniature Specialist, and I will do that. One never knows for sure until you contact them.

In closing I have to say that for the past week I've been thoroughly cleaning the train and everything that has to do with trains which includes going through all the boxes of parts and materials and reorganizing or trashing. Just this afternoon, at the bottom of a box of wood pieces I found a package with what looks like to be 100 square nuts that look to be threaded 00-90. No name - no nothing, so I have no idea at all where they came from. Grrrrrrrrrrrrrrr!

Sorry for the bad news but I will press on . . . . . Ken
 

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RE: Square Nuts & Bolts - I Have An Answer

Ken,

I'm not privy to your project but.....

Producing 00-90 square nuts is very much a specialty job due to size. I've done a bit of machining and would cringe at the thoughts of such a job. I routinely drill tap down to 1-72 and occassionally 0-80 but anything smaller gets pretty nasty. I think you got a VERY good quote though I know it seems very pricey.

The cnc program would be pretty quick to do. The .060 (.062"?) is, I believe, available but not in free machining brass that is required for such a project. To get free machining stock for your project would involve having it made at the mill ($$$$ with minimum ) or actually machining brass to that size. CNC lathe time is pretty expensive and your project might not be profitable for even a small shop that is busy. My guess is that those prices are actually low for a one time run. Amazingly, a similar run of larger square nuts made from .125 stock would be a small fraction of the price since it is just big enough to buy off the shelf stock and the parts are a lot easier to handle. I would also think that they would have to BUY a special collet for their lathe.

Frustrating, yes but remember that shop is trying to make profit to feed the employees and owners/investors.

What you want isn't a very simple request. I would suggest you need to find a shop that specializes in small micro fasteners and is more than willing to make short runs. If you could find a shop to make the stock that would be a good first step. Then find the specialty fastener maker. Another possibility would be an instrument maker. Metric might be easier???

Another way, albeit less conventional, would be to machine them from sheet stock. This would involve finding some free machining sheet of suitable thickness. Holes would be drilled. Holes would be tapped. Square nuts would be milled out. Tumble the nuts to deburr. Might be something a small shop could do but tapping the holes could be tedious depending on how they are done. If you could find a small shop to do this it might be the cheapest way. You might have them drill the holes and you tap them ( might take about 30-40 tedious continuous hours by hand) and then they could cut out the nuts but that would involve some work on your part.

I wish that Micro-Fasteners would supply square nuts 00-90 thru 6-32 but I don't think it will ever happen.

Could investment cast nut/bolts do the job?

Good luck with the square nut project!

Jack
 

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RE: Square Nuts & Bolts - I Have An Answer

Ken, I have been following these posts with interest, even though I have no thoughts of participating in a purchase. Have you discussed this with Bob Breslauer of Scale Hardware-www.scalehardware.com? Some of his products use square stock much smaller than 0.060, and he threads nuts to 0.5 mm.

Larry
 

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For sometime I have been try to make a square bolt head. Put either the 1-72 or 0-80 die in a vice or the die holder handle in a vice.
Put a 6 inch length of brass rod in a cordless drill and run at a low speed thru the die.
Cut to length. I drilled hole a little bigger than the threaded rod in a piece of steel. Put the short piece in the hole with a and try to peen it over.
Then file the rond head square. This work a couple of times but did not work most of the time. Tried different size holes. Some drill all the way thu and smoe not.
I think the concept is sound but the rod is so small as compared the hammer.

Then for the heck of it I put a short piece of copper wire in the drill and threaded it. It peened over nice but the bolt stem crippled.

Anyone tried this method?
 

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Discussion Starter · #5 ·
Hi Larry . . . .

No, I have not contacted Bob Breslauer of Scale Hardware, but I might do that.

I thoroughly understand the extra charges for a custom job but with todays CNC machine and CAD programs, wanting a dollar each [ plus the cost of material ] is nothing but a way of saying "I don't want to screw with you."

And if that's the way they feel, just say so. I would be fine with that. Just don't try to scare me away with outragious quotes for cost of materails, etc.

If you recall I ask for an estimate of 2,000 square nuts and the same number of bolts, all thread to 00-90. I believe I've already mentioned that during my "house gleaning and cleaning" I found a hundred or so nuts, 0.080 across the flats and threaded 00-90.

After a count, there were 342 of these little gems. [ Gold is only $1,000 an ounce ] No name on the little zip-lock baggy and no idea where I got them. But here's the kicker. Those 342 nuts take up less than 3/16" in the bottom of a 1" medicine bottle. The entire 2,000 and 2,000 bolts would go in that bottle with room left over. And this much material would cost "thousands". Not hardly.

And before anyone wish to tell me about the waste in doing this work, I am aware of these things. I am not totally ignorant when it comes to the machining processes.

I will keep plugging away. Everyone's interest is appreciated.

Ken
 

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RE: Square Nuts & Bolts - I Have An Answer

Hi,
unfortunatly I'm not common with these little numbers in the US measuring system. With inch it works for me more or less. In Germany we have a very good small enterprise with small sized screws and so on. Here is an example of a quare nut:
http://www.modellbauershop.de/assets/s2dmain.html?http://www.modellbauershop.de/index2.html
Maybe that helps. If you need to know more, you can send me an eMail directly.
Regards
Bernd
 

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RE: Square Nuts & Bolts - I Have An Answer

Ken,

I just got done doing some cnc work for the day and read your post. I work mostly cast metal parts but also do a bit of machining for customers when they twist my arm.

A long time ago I wanted a short run of brass stock made and I remember they said I needed to buy 500 lb. !!!! I didn't get the run made and was frustrated as I'm sure you are. I did a bit of checking on prices and I would guess that a run of brass stock would cost about $1750 + shipping and maybe more if the machine shop wants a small profit. Many CNC shops would charge about $120/hr with some sort of minimum. I'm going to guess that your small job might eat up the better part of 3hr.

I still say you might fnd what you want if you look into specialty shops. I would also contact some of the many model engineering suppliers in the UK as they may be willing to help.

Jack
 

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Hmmm, I just weighed some 2-56 1/4 brass bolts and get .009 oz. per bolt, so you can get 1777 bolts per pound but at, say, machining away half the raw material then you get 1/2 that or 888 per pound.

What does brass cost per pound? I am guessing $10 per pound so 888 of them has $10 in material. Assume it took the CNC programmer 3 hours to produce and verify the code and the setup took 30 minutes and operation to make one was 10 seconds.

The programmer gets the big bucks at $50 per hour plus overhead costs are often 100 percent of salary (or more) so that makes the cost of programming $300.

The machine operator gets $25 per hour plus 100 percent overhead (so $50 per hour) and it has taken him 31/60 of that to make one for a total of about $25.83. So the one bolt will cost $325.85 (I rounded to material cost up to 2 cents).


888 of them would cost:
$300.00(Programmer)+$25.00(setup)+$10.00(material)+$0.83(machine cost per unit)*888 units = $1017.04


2 pounds of material would produce 1776 units at a cost of:
$300.00(Programmer)+$25.00(setup)+$20.00(material)+$0.83(machine cost per unit)*1776 units = $1819.08


3 pounds of material would produce 2664 units at a cost of:
$300.00(Programmer)+$25.00(setup)+$30.00(material)+$0.83(machine cost per unit)*2664 units = $2566.12


Maybe you can plug in more realistic numbers and get a better result but you need to order over 2600 pieces before the cost is under $1.00 each and that is just for one of the nut/bolt pair and does not include anything like pure profit for the employing company.

Note also, I think my 50 percent loss of raw material is low for the bolts and VERY low for the nuts (the curf cutting off the nuts may be wider than the nuts themselves!)
 

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RE: Square Nuts & Bolts - I Have An Answer

Ken,

It has been my experience in machining that the smaller the tool you are using (tap/die) the higher the probability of breakage, and also the higher the replacement cost. The root diameter of a 00-90 tap is so small, I have no doubt that the slightest hard spot in the brass will cause the tap to break in a high speed CNC process. Now you are adding in down time to change the tooling and reset the machine. I break small taps regularly, and I have feeling in my fingers.

For what it is worth, if cost is really that important, search out a job broker that has contacts in China. I am sure you can get it done for pennies on the dollar that way. CAVEAT EMPTOR.

Bob
 

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Discussion Starter · #10 ·
Hi Bernd . . . .

I attempted a direct email to you but apparently it did not make it through, so will reply via the forum.

I tried the website you suggested, but unfortunately for me it is in German, and though my ancestors were German I neither speak nor read the language. And I found no way to convert it to English an option some sights have.

To convert these miniature nuts and bolts to metric I will get as close as I can.

Thread Size 00-90 = This I haven't determined and would depend upon bolt diameter listed below.

Bolt Diameter = 0.047" = 1.2mm

Square Bolt Head and Square Nut Across the Flat = 0.80" = 2mm

Heres hoping " modellbauershop" will have something close.

Ken
 

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RE: Square Nuts & Bolts - I Have An Answer

Bernd,

Your link didn't produce a page with a 'Vierkantmutter' (square nut) on it, but I did a search and found this link:

http://www.modellbauershop.de/df93b096a011e8a2e/53069399a909ac912.html

[Kenneth - I use Babelfish to do the translations for me; just copy and paste a bunch of text and it works it all out for you!]



The 'Maßtabelle' (table) says an M1,6 square nut is 1mm thick and 3.2 mm wide.
At 1 millimeter = 0.0393700787 inches. that's about 0.04" (1/64") thick and 0.125" (1/8") wide.

Amazing what the 'net can do for you.
 

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RE: Square Nuts & Bolts - I Have An Answer

Ken,
Hope you see this. I have FOUND your square nuts. 1.6mm and 2.0mm size. They are on a Model Ship Builders site in the UK. You can view them at www.modelingtimbers.co.uk They are under Products, then sub category of Brass Fixings. You amy have to search the site a bit but they are there. Hope this helps
Noel
 

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Discussion Starter · #13 ·
Noel . . . .

This is fantastic news! This is a marvelous site and the square nuts are indeed there, just as you stated. And there are some "rivet bolts" which will be perfect to complete the materials I need for fishplate installation.

I knew they were out there . . . somewhere . . . and thank you very much for sharing this bit of information and good news.

Have a wonderful weekend. If I could buy your lunch tomorrow, I would gladly do so.

Ken
 

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RE: Square Nuts & Bolts - I Have An Answer

Ken,
Lunch! Sounds good. Depends where you are located in the world. I just might show up on your door step. LOL!
It was quite by accident I discovered the site. It was posted on the 7/8ths Lounge site my mistake. I jsut happened to open it out of currosity. Glad I did.
N
 

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RE: Square Nuts & Bolts - I Have An Answer

Hey Pete,
Never wright emails and massages when you are tried and latte at knight.
Noel
 

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Hi All,
Just to point out the obvious, the exchange rate is $1.4 to the pound. Which makes Modelling Timbers 1.6mm square nut cost about $0.50 each.

Unless I've overlooked them on the web site, I also don't see ANY square headed bolts. The ones shown are hex.
So this still leaves you with trying to find the bolts.


A few years ago I was also looking for a supplier of Square Nuts and Bolts.
In a nut shell, I was told to forget about using a CNC lathe on such small stock. The only real option is to use a screw machine.

I contacted several shops that had screw machines. None of them were interested in any quantity under 10,000. At that figure, if I remember correctly, the price was about $0.25 each for a 2-56 x 1/4" bolt. Nuts were about $0.15 each.


Still too pricey for me.

Doug Bronson



BTW, the nails and hinges can be found at House Works.
http://www.houseworksltd.com/page_2.htm
 
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