What Steel to use when? Tools Steels Vs Low Carbon etc

[HobbyMaker]

I'm looking into material choices to make a couple of draw bar style tools for my lathe:

1. A headstock centre boss MT3 (Morse Taper 3) adapter for a dead centre for turning between centres with a draw bar setup
2. A headstock centre boss mounted ER32 collet chuck
3. Possibly other drawbar style chucks collet adapters in the future

Any ideas, references or wisdom would be appreciated

Questions:

1. What is the right steel to use for a job like this?
   • 4140 Tool Steel jumped to mind as the right thing but I couldn't remember exactly why I thought this and $$$ per meter I thought there might be a better choice on a hobby budget.
2. Tool Steel, Mild Steel, Low Carbon Steel, Alloyed steels etc
   
   • Any insight on when to use what steel would be appreciated, specifically with reference to custom lathe tooling? (and if any specific use operations are required for given steels)
3. Cold blueing, Oil, Water, Air Hardening Steel, etc
   
   • I was proposing to case harden the steel and a little unsure if this was unnecessary from memory 4140 offers no benifit without heat treatment(?)
   • I'm little concerned about order of operations if any thermal distortion occurred given the challenges of re-chucking and any possible need to surface grind after the fact.
     My heating tooling is limited to an Oxy/Acetylene setup so it would be a case of chasing the correct cherry colour before quenching and I have had mixed success with this kind of operation.
     I have been playing cold blueing lately, but not sure if it really offers the benefits of a true oil quench with respect to material properties and protections
   • Any insight or wisdom on the need or otherwise to go down this path would be appreciated?

Background:
I have been looking at creating a some tooling from my old Nuttal lathe to improve the accuracy of a number of turning activities. The Lathe has a nice quick change D1-6 camlock setup on the spindle with a reasonable 3 jaw and 4 jaw chuck but the repeat ability of the 3 jaw is just not good enough to re-chuck parts. I was looking into mounting a ER32 collet on a D1-6 Camlock backing plate but not sure I could get the accuracy I'm chasing without re-grinding the spindle nose and re-dressing all the chucks and backing plates (not really a job for the faint hearted)

So it occurred to me I could make a drawbar and plug style mount for the centre on the quick change spindle (it seems to have some kind of taper in the centre of the spindle nose as yet un-identified)

These probably aren't going to be given exceedingly hard service life but I would like to prevent surface rusting when not in use as much as possible. It maybe possible to any old steel successfully for this but its worth putting a bit of though into because I hate having to make things twice.

 

[technocrat]

with light service and machining only, use something easy to machine and see if you get the accuracy required. When it wears out or does not have the attributes required and you have heat treat and grinding available then call us back.

 

[jim rozen]

With O/A only you have no hope of through-hardening spindle toooling. Case hardening possible but not likely.

 

[memphisjed]

Cold blueing like the patina is not heat treating.
Quench substance (super quench, water, brine, oil, air, blanket) are chosen by the material.
Easy to harden and temper your own tooling, even with just a torch. Start with w1 and water, get out enough to not hold magnet (red hot) hold it about that color for a minute with your torch further away- let slowly cool on charcoal or soft brick, get it hot again the same way- quench then temper to desired softness.

 

[dgfoster]

For such a broad question a textbook is a good answer. And the book written to succinctly and authoritatively answer this and similar questions was written by Bryson. It is intended for use by folks doing one-offs with limited equipment who want to get good “professional” results. Very down-to-earth and practical, it is also based on good sound metallurgical knowledge and practice. About 40 bucks—-a bargain.

Item no longer available

The item you are looking for is no longer available.

www.abebooks.com

Denis

For the sort of things you are doing A2 or O1 be a good choice. Access to a small pottery kiln would be a real plus. Using an O/A rosebud, some ceramic wool, a magnet and Templsticks, you can do a good job making parts that will serve well. I’ve made a lot of em that way. Good luck.

Added: Making a small forge by stacking 8 or 10 firebricks and placing the workpiece in the “oven” for heating with an O/A torch allows you to heat a much larger piece far more evenly than holding it in a tongs in the open air.

 

[Joe Gwinn]

What I've used for shop-made drawbars is 1144 Stress Proof steel, as received, with no heat treatment (which would ruin 1144). Attachment of end nut to shaft is threaded, bottoming in a blind hole, and secured by the stud-locking grade of Loctite.

 

[WizardOfBoz]

An old book by Carpenter Tool Steel still has some hints:
Carpenter Matched Tool and Die Steels

I like it because it boils down a lot of choices into a matrix. Interesting, anyway.

 

[jim rozen]

Without a rockwell tester it's sort of like shooting in the dark. I second the stress-proof approach to life. Not clear that hardening tooling for this application has any real benefit.

 

[HobbyMaker]

Thanks everyone for the thoughts great to get so many considered opinions.

with light service and machining only, use something easy to machine and see if you get the accuracy required. When it wears out or does not have the attributes required and you have heat treat and grinding available then...

There is some wisdom in this approach that can't be denied, when I make tooling for myself I tend to over think it a bit hoping to solve the problem once and try never to revisit it.
I also find tooling useful to learn, try new techniques or skills I don't get to use all the time (I can looking back at a physical object helps solidify the lessons learnt, both good or bad)
@technocrat: So would you recommend just going with the cheapest low carbon (mild steel) no heat treatment or start with a higher grade steel? if so what would be your choice?

...for the sort of things you are doing A2 or O1 be a good choice. Access to a small pottery kiln would be a real plus. Using an O/A rosebud, some ceramic wool, a magnet and Templsticks, you can do a good job making parts that will serve well. I’ve made a lot of em that way. Good luck.

Added: Making a small forge by stacking 8 or 10 firebricks and placing the workpiece in the “oven” for heating with an O/A torch allows you to heat a much larger piece far more evenly than holding it in a tongs in the open air.

I have used a small propane fired brick forge quite successfully previously, I didn't even think of using it like a kiln. I have done some hardening / tempering with O/A but usually for smaller impact tooling. I didn't consider the difficulty heating the part evenly through with larger parts.

@dgfoster: I'm not overly familiar A2 or O1 (other then hearing the name O1 tool steel in passing) certainly never machined it. What properties of this material would make you recommend it? My quick research seems to indicate its $$$ like the 4140

What I've used for shop-made drawbars is 1144 Stress Proof steel, as received, with no heat treatment (which would ruin 1144)...

A quick google of 1144 Stress Proof looks interesting (https://bergsen.com/key-considerations-1144-stressproof-carbon-steel) from its advantageous properties and applications. Not sure on its availability in my part of the world (Australia) or its cost but perhaps worth looking into further

 

[Joe Gwinn]

I second the stress-proof approach to life. Not clear that hardening tooling for this application has any real benefit.

My thinking was that I was replacing an ordinary steel bar that worked for many years, so it was almost strong enough. 1144 was twice as strong, so will likely last forever.

 

[Scruffy887]

My thoughts on choices of steel almost always give high preference to what I have on the rack, or squirreled away in a corner. But the really good stuff is sometimes squirreled away in a corner I find after the fact.

 

[dgfoster]

I have used a small propane fired brick forge quite successfully previously, I didn't even think of using it like a kiln. I have done some hardening / tempering with O/A but usually for smaller impact tooling. I didn't consider the difficulty heating the part evenly through with larger parts.

@dgfoster: I'm not overly familiar A2 or O1 (other then hearing the name O1 tool steel in passing) certainly never machined it. What properties of this material would make you recommend it? My quick research seems to indicate its $$$ like the 4140

I recommend O1 because it is widely available in a great variety of sizes and shapes. It machines very easily. It is easy to harden and temper with a torch. It is tough and forgiving and has good wear characteristics. It is relatively cheap. As an example a foot of 3/4” ground bar is 31 dollars from McM. And I have used it to make hundreds of parts over the years. I keep it in stock in a variety of sizes as it is so handy to use.

To a lesser extent I have used A2 which is also very reasonable in cost and is extremely easy to heat treat. Its main claim to fame is even less distortion with heat treat than O1. It also is easy to machine. Both O1 and A2 are easier to machine to a smooth finish and close tolerance than common low carbon steels.

A2 hardens in air and O1 is commonly quenched in oil. I use canola.
But, in my view, the most useful advice I can give is to not to only listen to the necessarily brief and limited advice members here can offer regarding various steel choices, but rather get a copy of Bryson‘s book where you will get a much broader view and comparison of a range of tool steels and their application. As an example, fewer of us use S7. But it has excellent properties especially well suited for some fairly common applications and is also cheap, easily machined, easily heat treated, and unmatched in certain circumstances laid out well by Bryson.

Denis

 

[HobbyMaker]

....the most useful advice... get a copy of Bryson‘s book where you will get a much broader view and comparison of a range of tool steels and their application...

It does sound like a solid tip and looks like a good read for this kind of subject matter. Regrettably from a quick search what is $40 your end by the time it gets to the land of OZ and is converted to Aussie Pesos is $173AUD + $16.90 postage (yikes) but I definitely will keep my eye out for a paperback copy (must be available somewhere)

Either way thanks for all the tips and ideas

 

[LOTT]

You can also get 4140 Prehard (or PH, not to be confused with Precipitation Hardening), that gives you all the strengths without dealing with heat treat.

As to the collet chuck, why not just get a 5C chuck with a D1-6 back plate? You can dial it in and get excellent repeatability. ER collets are better suited for tool holding.

 

[dgfoster]

“It does sound like a solid tip and looks like a good read for this kind of subject matter. Regrettably from a quick search what is $40 your end by the time it gets to the land of OZ and is converted to Aussie Pesos is $173AUD + $16.90 postage (yikes) but I definitely will keep my eye out for a paperback copy (must be somewhere.)”

Tell you what, I’ll find a copy and sell it to you using eBay international shipping. I think your cost would be about 60 AUD for the book new and maybe 20 or 30 shipping. If interested email me

DenisGFoster
aattt geeemale
Dottt. commmm

Denis

 

[technocrat]

Thanks everyone for the thoughts great to get so many considered opinions.


There is some wisdom in this approach that can't be denied, when I make tooling for myself I tend to over think it a bit hoping to solve the problem once and try never to revisit it.
I also find tooling useful to learn, try new techniques or skills I don't get to use all the time (I can looking back at a physical object helps solidify the lessons learnt, both good or bad)
@technocrat: So would you recommend just going with the cheapest low carbon (mild steel) no heat treatment or start with a higher grade steel? if so what would be your choice?



I have used a small propane fired brick forge quite successfully previously, I didn't even think of using it like a kiln. I have done some hardening / tempering with O/A but usually for smaller impact tooling. I didn't consider the difficulty heating the part evenly through with larger parts.

@dgfoster: I'm not overly familiar A2 or O1 (other then hearing the name O1 tool steel in passing) certainly never machined it. What properties of this material would make you recommend it? My quick research seems to indicate its $$$ like the 4140


A quick google of 1144 Stress Proof looks interesting (https://bergsen.com/key-considerations-1144-stressproof-carbon-steel) from its advantageous properties and applications. Not sure on its availability in my part of the world (Australia) or its cost but perhaps worth looking into further

12L14 or whatever I have. The goal is prove the concept so easy machining with a good finish plus allowing time to experiment with the workflow. Most things don't need to be hardened unless they are used everyday. With the time saved, you can go through your tools and wipe them with an oily rag to prevent corrosion.
add: spend the time to single point for 90% or more thread engagement on softer materials with the added plus that you will get much better at doing it.

 

[Philabuster]

A quick google of 1144 Stress Proof looks interesting (https://bergsen.com/key-considerations-1144-stressproof-carbon-steel) from its advantageous properties and applications. Not sure on its availability in my part of the world (Australia) or its cost but perhaps worth looking into further

I second the 1144 Stress Proof steel. Easy to machine and does the job. It's not considered weldable steel due to the sulfur content in it.

You got a McMaster Carr equivalent down under?

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[boslab]

The problem with hardening isn’t one of heating, it’s how fast you can get the heat out, a drawbar should be easy, however during the heat extraction long slender stuff can and often does end up distorted, there are things like peritectic transformations that result in a rapid shrink as the face centred cubic phase converts to a body centred cubic structure, or the other way round, I buggered if I can remember which one , I think on reflection FCC is the densest pack so it’s BCC to FCC making the shrink or loss in volume, also the reason for skin cracks when hardening, the outside got its heat sucked out faster and shrunk, this particular transformation causes a lot of difficulty when casting steel slab and billot ( yes I used the word, correctly! Square section and round cast billot off a billot caster)
If you stop the casting machine or even slow it down waiting on the next ladle there is a real danger that the heat extraction of the mould will suffer the shrinkage of the slab or billot in the mould instead of in the spray chamber or straightener rolls, this pulls the steel away from the mould , often as much as 3/4” gap can appear between mould and steel, restarting casting results in an almighty bang called a breakout , breakout as the liquid steel pours through this gap and directly into the supporting remote adjustable top zone rolls and sprays, you get a nice steam explosion, the figure I was given was a kg of water going superheat was over 10,000 cubic meters of steam, long time since I used steam tables so I’m not going to attempt the calculation!
( med carbon casts best about 1450 C , lower it tends to freeze in the tundish etc)
This kind of transformation puts the curve in a samurai sword, not useful for a drawbar so on reflection I’d think of making the bar without hardening it, at least it will be straight!
You could harden just the thread but what’s the point, it’s a replaceable part, when worn, change it I think it will be a few years before that happens
Writing this reminds me I’ve forgotten more than I learned! Glad I’m retired now, but it’s still interesting
Mark

 

[HobbyMaker]

...You got a McMaster Carr equivalent down under?...

Not that I have found so far, lots of little steel dealers but mostly structural steels. No one whom tackles the full range of tooling & materials McMaster Carr does. Bit of a shame, but maybe they will one day open an Australia arm, probably would do solid business if it kept prices as competitive as they are in the USA.

As to the collet chuck, why not just get a 5C chuck with a D1-6 back plate? You can dial it in and get excellent repeatability. ER collets are better suited for tool holding.

Again a fair question, there probably are several reasons:

• 5C is less common in Australia and second hand collet chucks don't seem to come up as they do in the States. ER collets seems to be where China has standardised so they are fairly reasonably priced new and also come up second hand quite affordably.
• I have seen some nice 5C with D1-6 chucks and collets sets come up on eBay from time to time but most have a $500+ shipping cost which blows them out of the water as a viable option.
• I haven't been brave enough to re-grind the spindle nose yet (which probably would come up really nicely with only a little touch up but the consequences of messing up would be significant.)
• As a hobbyist I get more out of making a new tool (or restoring an old one) then I do just buying the new Chinese made part (Sometimes better made and cheaper, sometimes not. Either way I personally prefer and thus use more often tools I have a better connection with)

 

[michiganbuck]

The op seems to have left the site but still would like to comment.

http://www.lathes.co.uk/nuttall/
that Nuttal looks like a nice lathe.
Tecqnic is as important as the material centers are made of. Almost any older lath will have some error in the taper and so the most accurate center will run out and wobble from a tenth to a few thousandths. Putting a mild steel straight shank center in any chuck, and talking a tickle cut at 60* can be faster than taking off the chuck, inserting a center..and then after job replacing the chuck.
That is one great use of the fish gauge..a template gauge for checking the 60*
A turned-in-place center is the most accurate...and that center turning with the part saves the part center from wear and saves the machine center from wear.
Yes, you just dog off one of the jaws..and for the highest accuracy, use the same jaw if removing and replacing the part.

This also teaches the art of turning an angle by turning the compound..once you know the art, an accurate angle is easily made.

Being quick to go to and use centers and cut-off centers will make a clunker lathe and lathe operator able to perform high accuracy.

Cut-off and sacrifice centers are centers on a part that does not need to have a center, but the center is used to make the part..and then cut off.

Sometimes a female center can also be handy.