Fixture material 1

[ctopher]

I have been away from design for a few years.
What type of steel is suggested for a tool/fixture that will be placed into an oven for one hour? (couple hundred degrees)
I need steel that will not move or very little movement.

Chris
SolidWorks 09, CATIA V5
ctopher's home
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[MintJulep]

How big is the fixture?

How much movement (due to thermal expansion assumed) can be tolerated?

Answers to these two questions will define the maximum acceptable coefficient of thermal expansion that would be acceptable for you. Then pick a material with a lower number.

Depending on how little "very little movement" is, you may want a ceramic rather than metal.

 

[ctopher]

.020 max movement. It is approx 3x5 ft, 1ft tall. Don't have it available to get accurate measurements.

Chris
SolidWorks 09, CATIA V5
ctopher's home
SolidWorks Legion

 

[MintJulep]

So you are looking for a material with a coefficient of expansion of:

5 x 12 x a x a couple hundred = 0.020

 

[ctopher]

MintJulep,
Sorry, I have been away from materials for a few years.

I'm looking for a steel that sees 250F for at least one hour, may be in contact with some corrosive materials.
I need it to last, has metal to metal contact, no rust...or very little.

Chris
SolidWorks 09, CATIA V5
ctopher's home
SolidWorks Legion

 

[ctopher]

What is most common steel(s) these days for tooling/fixtures?

Chris
SolidWorks 09, CATIA V5
ctopher's home
SolidWorks Legion

 

[unclesyd]

What is the corrosive media?

 

[ctopher]

Some acetones, other acids, that I don't know the names yet.
It's a start up company and it is difficult to get info from others.
If you could please give me a range/type of materials, I can pick from the list.

Chris
SolidWorks 09, CATIA V5
ctopher's home
SolidWorks Legion

 

[unclesyd]

Without a little more information it is just a guess as what would be suitable.

For starters I would look at the appreciate size C/S mechanical tubing, available from any steel service center for the frame and if you need hard points I would use something like 17/4 SS machined to accommodate your component. The 17/4 would provide a nominal rust resistant hardened landing area. I would paint the CS with an appropriate paint for your environment, ours are painted with a high build inorganic/epoxy system.
There are some awfully good powder coating systems available at reasonable prices.

Interlakes has build quite number of bases and jigs for us especially if precision is involved.

http://www.interlakesbases.com/index.php

 

[ctopher]

Thank you. 17-4 is what I had called out for a couple parts, but the machinist advised against it without reason.
I will stick with it.

Chris
SolidWorks 09, CATIA V5
ctopher's home
SolidWorks Legion

 

[unclesyd]

Have the shop heat treat the 17/4 prior to any machining and they might be happier.
Depending on your requirements an H1100 (4 hours @ 1100F, air cool)heat treatment works quite well in most cases.

 

[ctopher]

Thank you.



Chris
SolidWorks 09, CATIA V5
ctopher's home
SolidWorks Legion

 

[btrueblood]

But...steel isn't going to solve your CTE problem. Mint's post points out you want something with an alpha of approx. 2x10-6 per deg. F. That's a ceramic, or a fixture designed with temp. compensation.