# Making tools from Stainless?



## StuNY (Mar 7, 2017)

I have started making my own r8 arbor's for slitting saws etc and for the first couple grabbed a bar of 416 stainless that was the right diameter. They cut very easily, gave me a nice finish and work very well in the mill. Any reason I shouldn't be using stainless for these (other than cost)? I like the idea of not having to worry about rust etc, and they sure are purty! I am not planning to harden them so wonder if I am fine with it or should be using regular carbon steel/tool steel. They are 5-6 inches long and at widest point 1.25" diameter, turned between centers and I am using carbide inserts in toolholder. 
Thanks!
Stuart


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## Bob Korves (Mar 7, 2017)

I prefer making straight shank slitting saw holders and using them in a collet.  We recently had a conversation on this topic:
https://www.hobby-machinist.com/threads/slitting-saw-arbor-types.55156/
The post by WreckWreck there shows a great idea for making mandrels that will run slitting saws perfectly true.


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## StuNY (Mar 7, 2017)

Thanks for the link Bob! That is an interesting approach to getting it perfect. I made another one last night that had a 7/8 straight shank for a collet and in addition to using a lot less material seems to be running even more true than the R8 versions.  Will indicate it tonight to see how close it is and then maybe try cutting the next one in the mill per WreckWreck's technique. Any downside to using the SS?
Stuart


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## mikey (Mar 7, 2017)

I like 416. It isn't particularly tough but it can be hardened at lower temps than tool steels. Corrosion resistance is not as good as 303 but the tool will be in the shop, not the back yard, so you'll be okay. If the tool is only going to see hobby shop use, I would say go ahead and use it. If the tool starts to wear too easily for your needs, grab a torch and have at it.


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## chips&more (Mar 7, 2017)

If it's just for hobby use...go for it!


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## Ulma Doctor (Mar 7, 2017)

i'm of the belief that if you have a material and a purpose, and the material is suitable for the purpose- use the material to full advantage.
if you have stainless available, use it !
there is no foul for using stainless steel for arbors and mandrels, but beware- it can gall.
light lubrication will help prevent galling


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## StuNY (Mar 7, 2017)

Ok guys, will keep using thanks! 
Ulma Doctor- where would I see the galling? Do you mean where stainless parts meet stainless parts or where the part meets a steel collet or r8 spindle- locking together?


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## kd4gij (Mar 7, 2017)

I would use never seize on  the threads for sure.


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## Ulma Doctor (Mar 7, 2017)

StuNY said:


> Ok guys, will keep using thanks!
> Ulma Doctor- where would I see the galling? Do you mean where stainless parts meet stainless parts or where the part meets a steel collet or r8 spindle- locking together?


Hi Stu,
anywhere there is a friction or slip fit.
if there is any rotation on the stainless member , it will soon want to gall
stainless to stainless (worst) , or, stainless to carbon steel (less problematical) should be protected.
i would use a small amount of light oil personally, but for the threads anit-sieze would be appropriate too.
just DON'T put the anti-sieze in the R-8 spindle


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## StuNY (Mar 8, 2017)

Oh, ok- thanks for that, great to know!


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## BGHansen (Mar 8, 2017)

According to the web, 416 stainless has less than 0.15% Carbon in it, so it shouldn't harden very well (close to 12L14 except for the chromium).  If it had 0.40% - 0.80% you could harden it and it'd be tough as a punch.  You'll be fine as long as nothing snags your arbor/saw.

Bruce


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## StuNY (Mar 8, 2017)

BGHansen said:


> According to the web, 416 stainless has less than 0.15% Carbon in it, so it shouldn't harden very well (close to 12L14 except for the chromium).  If it had 0.40% - 0.80% you could harden it and it'd be tough as a punch.  You'll be fine as long as nothing snags your arbor/saw.
> Bruce


That is interesting! I didn't realize it had so little carbon. I have been hardening 416 in the past making bolsters for knives and it does seem to get harder. Much less prone to scratching when hardened and the file skates across it. I never thought to measure how hard it actually got after treatment though since it was a decorative part and not the blade. 

I thought about heat treating these arbors but am worried that the part may warp slightly with the heat and require grinding back to true. I may give it a try with one of my original parts though that I don't intend to use and just see what happens. 
Thanks!
Stuart


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## Tony Wells (Mar 8, 2017)

Galling is less of a problem with 416 than most stainless materials. That's one of the design features. Having worked along with Carpenter Stainless a bit, I tend to use their material when I can get it, and lots of their tech data. Here's their datasheet on their 416.

http://cartech.ides.com/datasheet.aspx?i=103&e=79

Crucible is another good resource and they also market a 416 alloy

https://www.crucible.com/eselector/prodbyapp/stainless/cru416rs.html


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## StuNY (Mar 8, 2017)

Thanks for the datasheets Tony. Looks like crucible specs it at minimum RC35 when heat treated so probably worth going for it- time to crank up the HT oven!


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## Tony Wells (Mar 8, 2017)

You're most welcome. I like to refer to those whenever I start a project with a new material. Lots of hidden information can be gleaned from studying the datasheets from the people who make the stuff. Of course, some of it is sales pitch, but the actual specifications are generally not inflated or embellished and you can depend on them.


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## Tozguy (Mar 9, 2017)

StuNY said:


> I have started making my own r8 arbor's for slitting saws etc and for the first couple grabbed a bar of 416 stainless that was the right diameter. They cut very easily, gave me a nice finish and work very well in the mill. Any reason I shouldn't be using stainless for these (other than cost)? I like the idea of not having to worry about rust etc, and they sure are purty! I am not planning to harden them so wonder if I am fine with it or should be using regular carbon steel/tool steel. They are 5-6 inches long and at widest point 1.25" diameter, turned between centers and I am using carbide inserts in toolholder.
> Thanks!
> Stuart



Great idea, now I know what to do with some old barrel stubs.


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## StuNY (Mar 9, 2017)

Before I heat treat my original R8 mandrel I thought I would use an indicator to see just how straight it was to see if it warps after HT. Since I turned it between centers and it seemed to cut well I had assumed it was pretty accurate- it didn't visibly wobble like my original Grizzly arbor did. Nope! Mounted in the spindle and snugged down it shows 0.004" of runout where the blade mounts! So then out of curiosity I did same with the one I finished last night using a straight shaft that fits in 7/8 collet. Runout was 0.0005". I always assumed that a direct R8 mandrel should be more accurate but guess I learned what you all already knew- collet is better! 

Even at 0.0005" runout though, the slitting saw still makes that odd "cutting with a handful of teeth" throbbing sound. I am wondering if the slitting saw blade is not all that accurate. When I put an indicator on the blade from above at the full 3" diameter there was about 0.003" wobble as I spun it. The mandrel hub itself shows no measurable (by me!) wobble. I have another saw blade arriving today to check and see if consistent with above.


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## mikey (Mar 9, 2017)

Almost every slitting saw I have ever seen has at least one tooth or more that is slightly bent. The saw cuts with an intermittent scratchy sound; this is normal. As long as the cut is clean, I don't worry about it.


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## StuNY (Mar 9, 2017)

That is a relief Mike- thanks!


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## mikey (Mar 9, 2017)

StuNY said:


> That is a relief Mike- thanks!



Yup, you're welcome. If you don't mind, I'd like to offer some tips for using these saws:

These saws are intended to take a full depth cut from the start. Sneaking up on final depth just wears the blade and dulls them faster.
Proper cutting speed is the critical cutting parameter. I'm attaching a sheet from Martindale that will help. Speed is dependent on the material being cut; it will be much faster than you think.

Proper feed is almost as important. You want a positive feed; that is, you should feel a slight resistance to feed as you make a pass. Some folks use power feed but I find it better to feel the cut.
Most slitting saws have zero set so chip clearance is a major issue. Anything you can do to help clear the chips helps - air, a brush, and the coarsest saw you have that will do the job.

Heat is bad for a zero set blade. Using a lot of cutting fluid helps lube and cool the blade. I use a lot of paper towels under the blade to catch all the lubricant I apply. I also wear an apron to catch the oil that gets on me!
You should have the right number of teeth in the cut. The table I attached will give some valuable guidance. Having at least 3 teeth in the cut is a good rule of thumb. I use the coarsest saw I have for the job to clear chips but sometimes you only have blades with too many teeth. You can still use them but you have to feed slower.
Sometimes you need a slot width that is wider than the blades you have available. With zero set blades, you can stack em' if your holder will center the blades. This is why I like the Sierra American design; it allows me to stack several blades on top of each other while maintaining the concentricity of the stack. Of course, the blades have to be of the same diameter.

Use the smallest diameter blade that will do the job. This improves rigidity.
Hope this helps. And don't worry about that out of line tooth - the saw will cut fine.


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## StuNY (Mar 9, 2017)

Wow- that is very helpful Mike! I was having trouble using my speeds and feeds app with all these teeth! It happens that the blade arriving today is from Martindale. Now I can figure out if I ordered the right one haha! 
Thanks again for the help!
Stuart


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## Bob Korves (Mar 9, 2017)

You do not want too many teeth in the cut either.  The gullets will fill up with chips and then jam the blade in the cut.  If you have a long length of cut then you will need a correspondingly coarser blade.


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## Wreck™Wreck (Mar 11, 2017)

I work in a machine shop where there are 4-5 people running mills all day, can always tell when someone is using a slitting saw by the rhythmic throbbing sound, they always sound awful. We do a recurring job of 500 to 1500 parts from 3/8" CR steel round bar that have a .160"flat tang on one end using 2 saw blades spaced apart on the arbor, 3 parts in 3 vices on the table of a Fadal 4020, when the saws get dull it sounds like a helicopter landing in the parking lot, they maintain size but the finish is awful when dull. Nice finish and quiet when new however.

Slitting thin or hollow sections such as tubing can be very loud indeed.

As far as making a saw arbor from stainless, why not? Would not be my first choice but if you have it then use it.


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## Downunder Bob (Mar 12, 2017)

StuNY said:


> I have started making my own r8 arbor's for slitting saws etc and for the first couple grabbed a bar of 416 stainless that was the right diameter. They cut very easily, gave me a nice finish and work very well in the mill. Any reason I shouldn't be using stainless for these (other than cost)? I like the idea of not having to worry about rust etc, and they sure are purty! I am not planning to harden them so wonder if I am fine with it or should be using regular carbon steel/tool steel. They are 5-6 inches long and at widest point 1.25" diameter, turned between centers and I am using carbide inserts in toolholder.
> Thanks!
> Stuart



If you have a cheap source of S/S  why not, I tend to hoard the rare pieces that I can get, because it's expensive. The only down side with S/S it can be prone to chloride (salt) stress cracking, but in a hobby workshop it's not likely to be in contact with chlorides. so enjoy the nice shiny pieces.


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## StuNY (Mar 12, 2017)

Thanks guys. Still working through different steels for different purposes but enjoying the journey! Just a hobby for me so tool steels seem a little overkill for now. I got a pretty good deal on the 416 drops and like the way it machines. 12L14 is a lot of fun to machine too but it sure seems to rust quickly! I had written off 1018 due to surface finish and difficulty machining in the past but spent the day with it yesterday on the lathe and mill with carbide tooling running at full feeds and speeds and have to say I have changed my mind. Finish is coming out as good as 12L14 and it machines much faster than I had imagined. On my lathe and mill I can run pretty much full speed for most uses- I was using 200 RPM in the past hehe! I am finding it very helpful to keep the Little machine shops feed and speed calculator on my phone as I work.


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