# Question about 316 stainless steel



## Texatdurango (Jun 22, 2009)

I've been looking into using some stainless steel for making pen parts such as center bands, accent rings, finials and clips.

A few knowledgable folks suggested 316 or 316L stainless steel as a good allow to try.

Since several members are also looking into making their own clips, I thought I'd make a public post rather than continue gleening information via private messages, that way others might learn along with me.

My question:  Would either 316 or 316L in sheet form of 20ga (.036") be suitable for making pen clips?

My concern would be the "springyness" required to make a good clip.

So far I have learned that sterling silver makes lousy clips because it's too soft and titanium makes great clips because it's so springy but is hard to machine.  I'm looking for alternative material.

All help appreciated.


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## johnnycnc (Jun 22, 2009)

George,
I poked around a favorite steel suppliers info pages and found 
this for you, which should be of some help.
(almost to bottom of page is info on formability)
http://www.sandmeyersteel.com/316-316L.html

In my forming die experience many years ago, stainless was not common at our shop, but was used on occasion.
It appears to be a good choice for your application.


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## ldb2000 (Jun 27, 2009)

George , I would think that 316 SS would be ok for making clips but the thickness is a little to thick , .020 in SS would be a little better . You don't want the clip to be too stiff or it won't have enough flex . The steel clips that come with slimline pens are around .020 and have enough flex without bending so I would think that SS would be about the same . 
On the brass clips I have been making the thickness is .032 and so far no one has bent a clip without forcibly bending it , and any clip will bend if you force it beyond its normal flex distance . My brass clips will flex between 3/16" and 1/4" before they start to deform .
I think a more important factor is the grade of SS , you want the highest chromium and nickel content to get the brightest finish . Corrosion resistance is the main difference between the different SS alloys and for pen parts any of the grades of SS will work fine . I do believe that 303 or 304 is a little easier to work with . 
I know less then nothing about metallurgy so take this post for what it's worth , I only know what has worked for me .


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## Texatdurango (Jun 27, 2009)

Thanks for the info, I ordered some sheet, rod and tube from http://www.metalliferous.com/pdf/Base_Metal/stainless_steel.pdf

I ordered silver and brass from them before, didn't know they also carried stainless.


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## Paul Downes (Jun 28, 2009)

You may want to look into the SS grades a little more. Some of the grades require work hardening to get the spring desired for a pen clip. In the thinner stock used for a clip un-worked SS may be too soft and take an undesirable set with bending. Here is a link. http://en.wikipedia.org/wiki/AISI_steel_grades  Unfortunately, the SS that have good strength are the 400 series that have iron in it and there fore rust. 

You may have to make a die to form the clips. It will take some experimenting. It might work that you would form the clip in a certain shape and then reform the clips to final shape to work harden them to set the spring factor.  This isn't as hard as it sounds. A set of steel blocks cut to marry each other and polished could be used with the SS sandwiched between them and use a vise to force the SS to shape. 

I guess as a die maker maybe I should look into this?


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## pipecrafter (Jun 29, 2009)

All stainless steels contain iron, and it's the amount of other alloying elements that actually reduce the chances that it will corrode.  Chromium is the most common element, but others like molybdenum are also used.


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## Gulfcoast (Jun 29, 2009)

George--

--- to keep it simple ---

--- for center bands, accent rings and finials; the alloy 303 will do for all of them, it is the free machining austenitic grade of stainless steel. 416 will machine easier, but requires heat treatment to achieve it's properties (including corrosion resistance). 303 machines well, finishes well, is easily obtained in varying sizes at a reasonable cost.

--- for clips 304 may be the alloy of choice (stainless steel  coil springs are produced from this alloy) it is also readily available in varying sizes at low cost.

--- Mcmaster-Carr has a wide selection of all of these stainless alloys, incuding 316.

http://www.mcmaster.com/#

  Joe


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## greeneyedblackcat (Jul 1, 2009)

George,Did you settle on the 316 or the 304?


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## Gulfcoast (Jul 1, 2009)

George ---

---as an added note, type 316 is also used to make springs. It is usually used when maximum corrosion resistance is required (marine environment)

 Joe


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## bradh (Jul 10, 2009)

Stay away from 316L. The L grades are low carbon to help make them bend easier or reduce weld cracking.
   A pen clip is like a spring, you want it to spring back, not bend. Stainless is not a spring steel in the sheet form you buy it, it needs to be work hardened to develop spring like properties. You possibly can work harden it at home by hammering it on an anvil.  Do not heat the steel or this will anneal it and release the hardening. 
316 grade of steel is a nickel type stainless that is used for highly corrosive applications and when the parts need to be welded. I see that some spring manufactures do use this grade for stainless springs.
I hope this helps.


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