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How deeply hardened are flame hardened ways?

dgfoster

Diamond
Joined
Jun 14, 2008
Location
Bellingham, WA
I have a Monarch EE with flame hardened cast iron ways. It has some mild wear of the bed ways. I have not yet fully assessed how much wear there is. But thinking down the road, If it were to need grinding, how deep does the hardening go? I am sure that varies from brand to brand and maybe even from some early years to later years. Are there any general rules of thumb?

Denis
 
Good place to ask this is in the Monarch section

John,

Probably not a bad idea to ask there specifically about my Monarch on the Monarch forum. And I will do that if I don't get a good answer here. On the other hand, there are some folks here who have done a lot of grinding on a lot of machines. I actually had an interest (and suspected there might be others who would find this of interest) in getting an answer specific to EE but also more generally relating to a variety of machines. That is why I was asking about a rule of thumb. Maybe there are no general rules. But I had an idea someone like Cash might have a fair bit of experience that he and others might share. Not so sure he and other experienced grinders frequent the Monarch group. So, I thought I'd try here first. Let's see what happens.

Denis
 
I think if you call up and ask Monarch themselves in Sidney, you will get the answer that they will regrind once and sell it to you as an authentic rebuild. The second time around, they will not. They have probably done the destructive testing well in the past as part of the engineering.

My guess is that most bedway grinders aren't doing a portable Rc test on the ways after they grind ;)
 
I have a Monarch EE with flame hardened cast iron ways. It has some mild wear of the bed ways. I have not yet fully assessed how much wear there is. But thinking down the road, If it were to need grinding, how deep does the hardening go? I am sure that varies from brand to brand and maybe even from some early years to later years. Are there any general rules of thumb?

Denis

Early ones, not very deep..... Later ones up to 1/8 inch or so the legend goes...

Reason being through out the years better alloys were used to cast the beds and better flame hardening equipment and techniques were developed...
 
Thermite

You say they scraped hardened bedways ???
or am I not reading correctly
never seen that

BTW when you grind a bedway don't you know when you go through the hard layer ???


peter from holland
 
Thermite

You say they scraped hardened bedways ???
or am I not reading correctly
never seen that

BTW when you grind a bedway don't you know when you go through the hard layer ???


peter from holland
.
carbide either a scraper or a milling cutter will cut through hardened steel. those used to only hss cutters might be surprised. i admit you have to take lower depth of cut with harder materials but i have never seen where it could not be cut with carbide
 
Thanks to all for the answers so far. To go along with what DMF said, a few weeks ago I did just test the possibility of scraping by using a sharp carbide scraper to take a couple of small scrapes down at the tailstock end where there was no discernible wear and where a scrape or two could do no harm. Indeed the scraper cut, but with more resistance and not as deep a 40 grey cast iron. But, it cut enough that it seemed like scraping would be feasible.

Denis.
 
I submit you HAVE seen at least the results if not the work-in-process.

Surely you do not think that every bed you ever saw that had been scraped - or even flaked - was a SOFT one do you?



Bill

In fact I do think so

Its been a while since I have seen a scraped lathe bedway anyhow
Only the very old ones I saw were scraped And even the soft ones are just ground on a rebuild
And if it is more accurate why have the Schaublin 135 and the Hardinghe HLV ground bedways Not scraped
to me it seems a hell of a job Who has done one You Thermite ? Nick? Richard ?

If I would detect that I went through the hard layer I would stop the rebuild
I ame sure you notice On eighter the sparks and/or the looks of the ground surface

Peter from holland
 
I use to work a lot on Hardinge lathes for a local distributor (Milton Granquist) and if the bed had only wear in the bed plate we would grind them once, if they had scratches from a carbide tool that got stuck under the wiper we would buy a new plate. I was going to wait until Monday to answer the question and call my contact at Hardinge and ask how deep the flame hardened beds are as I can't remember the depth, but when you ask me in a post, I wanted to say something.

I hate to guess on here like many do and give you the right answer and not a guess. I believe it is .008". I will write PMC the research center I work with in Taiwan and ask on new CNC machines.

As far as scraping a hard bed, I would never do that as the carbide will skate on it. Get chicken scratches, waste a lot of time and money plus when you are done it would look like hell. I wrote a week or so ago about lapping hardened ball ways on Fellows gear testers years ago when I assisted a Fellows tech re-calibrate a few. I have also used a small angle grinder /sander to straighten beds on CNC lathes in the field when in emergencies. As a rule of thumb your best to get them ground once at a Grind shop. Rich
 
I did call Monarch and they said the bedways would be hardened about 1/8" inch or less in depth. Sonded like it could be 1/16th to 1/8th. That should be plenty for most EE's you'd think unless they were severely worn. He also cautioned about the well-known alignment issues post-grind that might have to be taken care of. For Monarch owners considering a regrind it seems like a call to them first would be in order regardless of who was going to do the grind. He also pointed out Monarch's regrind service which he said they provide often.

Denis
 
I'm sure Harry will comment sooner or later, but he posted a series of threads on hand scraping a 10EE. I believe that recently he said he also would never do it again.
 
Whilst we're on this subject anyone have any idea which hardens the deepest ? Flame hardening or Induction hardening ?
Neither one is intrinsically deeper-hardening than the other. It all depends on the details of the setup. Slight edge might go to induction hardening, because splash from the quench jets isn't going to interfere with the heating action.
 
I checked with my friend at PMC (Taiwan Precision Machine Tool Research Center) and here is what he said.
"I ask one co-worker who is skilled in this area, he says it is .079" to .118" for cast iron in general Machine Tools hardened ways purpose. and the hardness will be HRC 48+3." Haven't heard back From Hardinge.
 
I have had no experience with flame hardening ways for machine tools.

BUT-I have had this experience on liner plates for steel mills. Basically the same process.

I say .060" deep is the "sweet" spot. After that you will loose HRC.
 
Rich,

That is almost identical to the information I got from Monarch concerning the EE. Interesting.

I was talking to someone else knowledgeable in the realm of flame hardening and induction hardening who pointed out that one should expect the hardness to fall off the deeper you go from the surface. I had not really thought about that, but I guess it very much makes common sense. So that there is not likely to be an obvious border between hard and non-hardened states. In the broken chill-hardened bedway posted by John you can see this progression from very dense crystals to coarser (softer) crystals as one goes deeper into the bedway.

Denis

Edit Typing while Cash was posting.
 








 
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