[cheddar11]

hi all I'm looking for 20-30 small barrel parts.

bascially a cylinder with a hole through it

0.024" diameter for the cylinder
0.008" diameter hole

height is 0.046"

I also need the top of the cylinder taken in a bit so the top diameter is 0.016"

material is stainless steel

[abcmojave]

Is the hole axial or radial?

What type of SS?

Tolerances?

[cheddar11]

Here is the pic of it. Tolerance is 0.0005"

For type of stainless 303 304 is okay 316 which ever is cheapest and won't rust.

[abcmojave]

So your units are now what, mils? Do you really mean 4.0005? The hole goes all the way through?

[cheddar11]

yea this drawing is in milli-inches. No I don't mean 4.0005. 4 mill-inch is fine. The hole goes all the way through

[northernmach]

yea this drawing is in milli-inches. No I don't mean 4.0005. 4 mill-inch is fine. The hole goes all the way through

Out of curiosity and confusion, what is milli-inches? I am sure I am not the only one questioning this.

[northernmach]

Think I answered my own question, and was what I was assuming. Your first post makes more sense to me than your dwg. I would show those dimensions on your drawing in a decimal format. And then just specify that it is in inch units. Very small parts then! Nothing I want to tackle!

[John Bennett]

To add confusion further, tolerance of .0005 mm is equal to 0.000019 inch, if this is correct. Sure counts my machine out except on a fine day in September when the sun is just right.

[northernmach]

To add confusion further, tolerance of .0005 mm is equal to 0.000019 inch, if this is correct. Sure counts my machine out except on a fine day in September when the sun is just right.

I think you are looking at it the wrong way. I was also doing this at first. Read the first post he made and to me it sounds like everything is in inches in decimal format not metric sizes. His drawing is what is causing the confusion I think. The drawing makes it look like metric sizes.

[Donkey Hotey]

Perhaps if the original poster could describe how big this part is, somebody could decipher what units it's in. I'm not entirely sure that what he dimensioned in the first post is really what he wants.

Not trying to be an ass but, you realize that the part you are describing is smaller than a pencil lead, would have a hole that is tough to see and you'd have to hold it with tweezers, right? We're talking about a broken chip off of a grain of rice as an overall size. That's what you need?

Is this some kind of restrictor jet? How critical is that through hole? At that size, I can't imagine being able to hold (or measure) a tolerance with common measurement tools.

[cheddar11]

hi everyone sorry for all the confusion the drawing caused.
The drawing is in mils aka 1mil = 0.001 inch.

So the hole is 0.008 inch that goes all the way though
The diameter of the part = 0.024 inch
The height is 0.046 inch
and the taken in part is 0.016

The part is for a watch thus the small size so the hole does need to be with a 0.0005 inch tolerance.

[Donkey Hotey]

I'm going to stick my neck out here and say that you aren't going to find anybody that can pull that off using conventional methods.

• The 0.008" through hole is going to be nearly impossible to hold tolerance. Drill holes are notoriously imprecise.
• The fact that it's stainless and the hole is over 5D (5 times the diameter) deep means it's going to be tough to drill the hole at all without snapping the drill.
• Finally, the remaining wall thickness on the necked-down portion is only 0.004". If the hole is drilled first, the machining of the shoulder will just roll that material over before it cuts. If the turning is done first, the drill will simply tear off that 0.004" thick wall at the edges. You're at the dimensions where the remaining material is nearly the same size as the chips.

I'd guess the outer diameter turning MIGHT be able to be done with micro-tooling but, the holes will need to be electron-beam drilled or EDM drilled.

That's my take on the part. I'll be interested to see if anybody thinks otherwise.

[Dualkit]

It is doable, but you would have to have a near new 16MM or less CNC Swiss Screw Machine, with ground material, new headstock collet, new guide bushing, and new collets for the spot and drill. Also be prepared to snap a lot of drills before you magically get one that tightens down within .0002 t.i.r. to the drill spindle. .004 wall is easily turnable on something that short. Even with a shiny new machine anyone who bids these at less than $50 each + tooling is going to lose money. You could take a perfect machine and a top notch set-up man and I would bet it takes 3 days to a week to get 30 good parts. It looks like a good challenge, but not on my 10 year old + swiss machines.

[bjorn toulouse]

hi all I'm looking for 20-30 small barrel parts.

bascially a cylinder with a hole through it

0.024" diameter for the cylinder
0.008" diameter hole

height is 0.046"

I also need the top of the cylinder taken in a bit so the top diameter is 0.016"

material is stainless steel

You really should be looking for tube stock that could be ground to the finished diameters.

You need to be more specific about your tolerance requirements.
You state ".0005". So, are you talking +/-.0005, or +.0000/-.0005, or +/-.00025?
Is the tolerance for all dimensions, or just the hole?

Do a Google for "micro bore stainless steel tube".


Rex

[azmachining]

Why you won't find it, the largest OD available with that .008" hole size is .01630".

[bjorn toulouse]

Why you won't find it, the largest OD available with that .008" hole size is .01630".

Google is your friend!

Here's 316SS seamless tube:
Products


Rex

[Dualkit]

Google is your friend!

Here's 316SS seamless tube:
Products


Rex

What is it spec'd to for t.i.r. ? Even some of that small tubing can be .003-.005, and that wouldn't work on this job.

[romeu.jolit]

I have really long hair, and because of that it is hard to keep a curl in it sometimes. It holds a curl really well, but because it is so long the curl tends to fall out.

[K3Craig]

Everybody has very valid points! Dualkit, you are absolutely right, what you said about the 0.004" wall can happen...and has happened. If any of you get the chance, or can, on our facebook page is a photo of a 1/8th scale 1947 Harley. The guy who is building it made everything! Including the valves to put air in the tires, they are right around 1/32" in dia. and function just like a real one. Truely amazing. The spokes as well, he threaded the spokes, and tapped the nuts in the rim to accept the spokes, just like a real bike does. Throttle cable...everything. Ohh...and its meant to run when finished. When I met him, he was cutting a 0.060" dia 8 tooth bevel gear for the transmission that will run the speedometer. He was doing it on a Sherline mill with a 4th axis and a microscope in front of it. He also made a very small bolt, the hex head was 0.4mm and it too was threaded and he made a nut to match....the threads only being 0.0005" deep. And made a wrench to use on it.
Point being, it is possible. Probably not at a production speed, but if you want a part that small, its going to take time, and money. The trick is, everything is easy when its big, so.....make it big! In Jerrys case, he made it big with the microscope.... just sayin'

[terricaryan1]

So your units are now what, mils? Do you really mean 4.0005? The hole goes all the way through?

yea this drawing is in milli-inches. No I don't mean 4.0005. 4 mill-inch is fine. The hole goes all the way through
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