Myford induction hardened beds

[Compulsive purchaserParticipant @compulsivepurchaser]

My early Super 7 power cross feed model has an induction hardened bed however there is no riveted plate signifying this present on the front face of the bed (I have the original receipt for my machine stating the hardened bed was specified at purchase)

Am I correct in thinking that prior to the plate being fitted the Super 7’s were painted white between the two bed faces to signify the induction hardened bed, instead of the usual cream paint for the standard bed?

[Compulsive purchaserParticipant @compulsivepurchaser]

[HopperParticipant @hopper]

Don't know about the paint but Myford still sell the "Induction Hardened Bedways" plate on eBay if you wanted to fit one.

[John HaineParticipant @johnhaine32865]

An easy upgrade then.

[Alan DonovanParticipant @alandonovan54394]

As an ex Myford (Beeston – 60s/70s) employee, l can confirm Induction Hardened Beds we’re painted a different colour to the standard bed. But sorry I cannot remember what colour that was.

May I suggest you talk to the ‘new’ Myford about this for confirmation.

Regards. Alan.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by John Haine on 21/04/2022 07:01:31:

An easy upgrade then.

.

MichaelG.

.

Edit: interestingly, this is listed as suitable for the ML10

https://www.ebay.co.uk/itm/373512849086

Edited By Michael Gilligan on 21/04/2022 08:32:45

[Ady1Participant @ady1]

You could test the bed with a sharp screwdriver

[Douglas JohnstonParticipant @douglasjohnston98463]

When I bought my Speed 10 brand new from the original Myford many a long year ago I asked for the bed to be induction hardened. I was then told that this was not an option for the Speed 10 so I wonder if it was ever an option on the ML10 or Speed 10.

[John HaineParticipant @johnhaine32865]

My big bore S7 was ordered with an IHB but the bed is the same colour as the rest of the lathe, and I'm fairly certain as the non-IHB version. It does have the plate, I don't think I'll be testing the bed though.

[HopperParticipant @hopper]

Usually CI beds etc are not hard-hard like hardened steel anyway. Just harder than untreated cast iron. So a scratch test could be a bit inconclusive.

[Tony Pratt 1Participant @tonypratt1]

Posted by Hopper on 21/04/2022 10:24:33:

Usually CI beds etc are not hard-hard like hardened steel anyway. Just harder than untreated cast iron. So a scratch test could be a bit inconclusive.

My Warco lathe is meant to have an induction hardened bed, it has the nice shiny label but I'm not convinced it has been 'hardened', as you say a scratch test is inconclusive.

Tony

[SillyOldDufferModerator @sillyoldduffer]

Posted by Tony Pratt 1 on 21/04/2022 12:46:31:

Posted by Hopper on 21/04/2022 10:24:33:

Usually CI beds etc are not hard-hard like hardened steel anyway. Just harder than untreated cast iron. So a scratch test could be a bit inconclusive.

My Warco lathe is meant to have an induction hardened bed, it has the nice shiny label but I'm not convinced it has been 'hardened', as you say a scratch test is inconclusive.

Tony

Anyone know how hard a cast-iron lathe bed can be made? I found some figures suggesting induction hardening could lift the hardness of ductile cast-iron from about 15HRC up to about 50. So not in the same league as HSS (about 65HRC) or Tungsten Carbide about 90HRC. Grey cast-iron is less suitable.

Seems to fit; although they don't like it much you can machine HSS with Tungsten Carbide and chilled cast-iron with HSS.

For best results items are induction hardened more than once. My guess is a hobby lathe only gets one pass because each quench risks cracking the casting and writing it off.

My lathe bed claims to be induction hardened and it's distinctly harder than my mill table which doesn't. Better than not bothering but don't expect miracles,

Dave

[Michael GilliganParticipant @michaelgilligan61133]

This local firm has some notes which may be of interest : **LINK**

http://www.inductionheattreatment.co.uk

MichaelG.

[Alan DonovanParticipant @alandonovan54394]

Hi again. Further to my previous post on IHBs.

The castings for the IHBs were cast from a more 'exotic' grade of iron than the standard beds, that was more suitable for induction hardening. Production runs for the ML10 were much smaller than the 7 series machines so probably not high enough to offer the option of Induction Hardening on the ML10 beds.

At the time the 7 series lathes were designed, these were serious Industrial Standard machines. These were later followed by the MiniKop, 245 and 280 series lathes.

I may have inadvertently misled one of the previous posters – The machines whether they had hardened or none-hardened beds, were always painted the standard Myford grey (unless a special order), it was the trough between the bedway shears that was colour coded to identify whether it was an IHB or not.

I suspect that I had left for 'pastures new' when the IHB name plate was introduced, so I cannot comment if colour coding of the beds continued after that.

Alan

[John HaineParticipant @johnhaine32865]

Aha! So the trough down the middle of my bed was painted white, which checks out! Though now it's dirty grey…

[Chris TriceParticipant @christrice43267]

Mine is a green IHB with the plate saying so and the middle of the bed is an off white.

[HopperParticipant @hopper]

Posted by Alan Donovan on 22/04/2022 14:10:53:

Hi again. Further to my previous post on IHBs.

The castings for the IHBs were cast from a more 'exotic' grade of iron than the standard beds, that was more suitable for induction hardening….

That might explain why some of the Chinese lathes claiming to have induction hardened beds don't seem very hard in that area. (Quite soft in fact). If they don't use the higher, more expensive, grade of cast iron, it is not going to end up as hard as the better stuff.

[John HaineParticipant @johnhaine32865]

Posted by Chris Trice on 24/04/2022 02:58:27:

Mine is a green IHB with the plate saying so and the middle of the bed is an off white.

Ah, I should have said "off white" – though dirty grey is a better description of mine! 20 years of cutting oil…

[Compulsive purchaserParticipant @compulsivepurchaser]

Thanks for replies,

Mine is a early Power Cross Feed with induction hardened bed lathe in original Myford grey before the changeover to green, however the trough is painted Myford green, which I had assumed had been repainted so I was going to repaint it the correct white, however on closer inspection the green looks to be original, there is no trace of either white or cream underneath it, so I will leave it as is!

[Chris TriceParticipant @christrice43267]

Am I right in saying the hardening only extends into the bed a few thou deep?

[Alan DonovanParticipant @alandonovan54394]

Posted by Chris Trice on 24/04/2022 12:51:54:

Am I right in saying the hardening only extends into the bed a few thou deep?

Hi.

This is an opinion based on my observations of the induction hardening process while at Myford (Beeston). I am unable to back it up with any data.

The IH head moves along the bed and heats the top 15% of the bed shear depth immediately under the IH head. Once heated to the required temperature it is immediately quenched, thus hardening the material.

I would expect the upper surface of the shear to take on the full hardness from the process, and the material to be progressively softer as you go deeper into the material. There could (?) also be a tempering effect on the surface layers of the shears from the heat held deeper in the metal. The bed would then lose a little metal by the final bed grinding process.

So I would anticipate that that the FULL hardness depth to be only a few thou deep.

Alan

[LathejackParticipant @lathejack]

I remember when Myford used to advertise the option of a hardened bed for the Super 7 it stated that a hardened bed was not available for the long bed Super 7, I was always a little puzzled by this.

So on one of my visits to the Myford works at Beeston I asked Mr Moore why hardening was not an option for the long bed. He replied that it was simply because at the time he had sixty long bed raw castings in stock that were cast from a grade of iron that could not be hardened. This wasn't many years before he decided to sell up, so I wonder what happened to all those bed castings.

Anyway, I still miss the old Myford factory and the odd chat with Malcolm Townsend.

[egaParticipant @ega]

I have a fairly distinct memory of being shown round a workshop with a long, induction hardened bed S7 many years ago.

[SillyOldDufferModerator @sillyoldduffer]

Posted by ega on 24/04/2022 23:16:50:

I have a fairly distinct memory of being shown round a workshop with a long, induction hardened bed S7 many years ago.

Quite likely hardeded long-beds were made at times, just not consistently. Lathejack said ' So on one of my visits to the Myford works at Beeston I asked Mr Moore why hardening was not an option for the long bed. He replied that it was simply because at the time he had sixty long bed raw castings in stock that were cast from a grade of iron that could not be hardened. '

As Myford were in business for over 70 years and the Super 7 was in production for about half a century, like as not that the exact specification varied over time. It's unusual for manufacturers to make everything themselves in-house, because specialists normally knock out better components for less cost. Unlikely Myford ever made their own nuts, bolts, washers, motors, paint or electric cable!

Does anyone know which parts Myford made themselves from scratch? My guess is most components were outsourced: castings, electrics, gears, bearings, belts, paint, lead-screws, handles, etc. Myford owned and improved the design, accurately machined the lathe-specific parts and completed the lathe to a standard. Much more than a simple assembly operation but not everything was made by Myford, and some variation is inevitable.

Dave

[Ex contributorParticipant @mgnbuk]

Does anyone know which parts Myford made themselves from scratch?

Can't say definitively, as I only visited their works a few times on the open days & when passing to get spares plus I own '60s built version, but probably more of the metal bits than you might of thought.

Small screws & nuts (like gib screws & locknuts & the special dome headed screws for the switch bracket as examples) on my lathe are different in design & rather better made than some"commercial" stuff + are chemically blacked rather than left bright. On one open day visit, a CNC lathe had a stillage full of leadscrew handle bodies (later solid type) made from bar stock next to it & in the gear cutting department one machine was set up making the keyed changewheel sleeves. I would not be suprised to find that they made (or machined from bought -in castings) most items in house.

Some years ago I "found" a British Casting Research Institute (or similar UK trade body) pamphlet from the '50s in a Hay on Wye bookshop that featured the ML7/Super 7 bed casting as an example of state-of-the-art mass production casting technology of the time, plus the use of die cast parts for brackets, covers etc. suggests that Myford were using the best available technology when the ML/Super 7s came out to maximise production at lowest unit cost. I would also expect that, coming out of a period of war production, that they were probably "self sufficient" with regard to what may now be regarded as "bought in" small parts to better guarantee production during uncertain times – continuing to make such small parts in-house would give better control of costs as well as supply post war ?

WRT to bed paint colours, my un-hardened mid-60s built Super 7 has the gap between the shears painted the same cream that the cover logos are highlighted with.

Nigel B.

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