What steel is this? VCR head shafts

[Tokarev]

I've collected quite a bit of these shafts. They are 6mm in diameter and about 45-50mm long, which in inches would be slightly less than 1/4" by almost 2"
The steel is 1) stainless and 2) so hard that HSS tools can't mark it.
I am wondering if I should be able to anneal them to use for blanks and re-quench later.
If anyone is familiar with this steel, appreciate your input!
The shaft is the one that's protruding from the aluminum head thru the brass bushing in the picture below.

http://www.instructables.com/image/F6X8R9VGGPEY3PI/Gut-the-VCR-Head.jpg

[zuke]

You sure it's stainless?
Sound's like a long dowel pin or drill rod.

[Tokarev]

It does not rust in my humid basement where carbon steel does.

[zuke]

Not sure then

[Uncle Grinch]

Is it magnetic? High grade 316 or higher is barely magnetic. 18-8 is slightly magnetic.

[Tokarev]

Slightly magnetic.

[bearcove]

303 is used for shafts. Don't know how you would tell without getting a piece tested.

Other alloys other than "Stainless" are corosion resistant.

[paul h]

One thing I've learned from studying knifemaking is that "free" unknown steels can be the most expensive to use when you factor in the labor of making them useable. Some steels are air hardening, so annealing them is a real bugger and may require a computer controlled furnace to cool them slowly enough.

You're probably better off ordering up a length of tool steel from a machine shop supply house in whatever dia you need.

[Red River Rick]

...............You're probably better off ordering up a length of tool steel from a machine shop supply house in whatever dia you need.

That's probably the BEST advice yet!

RRR

[Tokarev]

I can still grind them into the reamers w/o heat treatment :)

[W.R.Buchanan]

Ditto Paul and RRR; It could be anything.

Also lets just say it is 440C and has been hardened. You can't just anneal it by heating it up and cooling it.

It has to be brought to hardening temp in an inert gas or vacuum furnace and reduced in temp so many degrees per hour until it is soft. This costs more to do than hardening the material in the first place.

Or you could buy a drill blank that is close to what you need from McMaster-Carr for a few $ and throw those rollers at passing cars or bad dogs...

Randy

[Cap'n Morgan]

I can still grind them into the reamers w/o heat treatment :)

Don't be surprised if the core of the shafts turns out to be soft. Many critical components are heat treated this way to combine hardness with strength.

[MBTcustom]

I agree with Cap'n Morgan. They could be case hardened. Also, just because they are hard does not mean that they will make good cutting tools. A steel that is designed for toughness may be lousy at wear resistance.
But hey, what do you have to lose? Grind an edge on one and use it like a single point tool in the lathe and see how long it takes to get dull and start glowing red. If it holds up really well, run with it!

[MtGun44]

If they are free, try one out. Heat to red heat on one end, then slowly pull the torch
back and let it down off of red over 10-20 sec, then let cool naturally. This is not really
annealed for many alloys, but will be far softer with almost all. See if you can work it
in that state, or even before wasting that time, (since if it is a work hardening alloy like
the 300 series of stainless steels and might not be heat treatable after you do the
work on it), once you verify it is softer (file cut it easily?), verify that it will reharden
by reheating to cherry red and quench in water. Recheck hardness - file should skate on it if it is
a heat treatable alloy. If it stays soft after a water quench from red heat, you have
a non-heat treatable alloy and you have to work with it the way it is or annealed (really
normalized, not fully annealed for many alloys).

Ultimately, you will have to do some 'rough and ready' development to get the hardness
vs brittle/tough behavior you need for your application. Basically you heat soak (temper) it at
some temp (say 700F) for a few minutes, then let air cool (this is after water or oil quench
from very red hot) and see if it is too brittle (try to bend or hit with a cold chisel). If too
brittle, try 800F for a tempering temperature. This will be softer but less brittle than a 700F
temper.

As somebody said - you can buy some drill rod and get the mfgrs specs on what heat treat
to get what hardness, but free is free and if you want to experiment, try the above - take
notes.

Bill

[smokeywolf]

Not sure what you've got there, but because film & tape has a propensity for building a static charge and curling or cupping, most duplicating and editing equipment has to be used in 50 to 55% humidity. For that reason most of the materials used for shafting is 316 stainless. If the shaft needs to be hard and corrosion resistant 440c stainless that's been heat treated. If corrosion, heat, and hardness were a concern than we usually turned to Hastelloy C; miserable to machine.

It does resemble a dowel pin, and Cap'n Morgan and goodsteel may indeed be right about the hardness being just surface. I've seen your typical cased steel dowel pin stay rust free for quite some time if it has just the slightest coating of a lube on it.

Stainless dowel pins are used frequently and are slightly magnetic, but they can be marked with HSS.

smokeywolf