I suspect you'll be wasting time unless the material is fully annealed. If you remove one side of spring material it is unlikely to stay flat. Better to start with known material than waste time with unknown material.

I'd face something that size on the mill, but I have a large mill. Alternatively I'd use a 4-jaw chuck in the lathe. Depending upon the hardness/temper HSS tooling may, or may not, work.

Andrew

Rather depends on what size 4-jaw you have for the myford, I you have one of the slim body 6" ones then no problem to hold in that with two opposite jaws reversed A 5" should also do it but would need all jaws reversed.

If you started with a longer bit you could drill & CSK the ends so it could be bolted to the faceplate then cut off the ends once you have it down to thickness.

Edited By JasonB on 24/04/2022 18:17:17

Can you cut it overlength, hole in each end, bolt to faceplate. When you flip it over you'll need a packer underneath as obviously you cant face where the bolts are

Same idea, but cut a rough pair of flats with an angle grinder to take strap clamps that are bolted down to the faceplate. The plate is blocked up on a piece of wood to allow the cutter to clear the bolt heads.

If there's not enough room on the faceplate for a straight strap angled from the lip to under the bolt-head, then make some Z or C-shaped clamps to fit.

Dave

A significant amount of work and ingenuity required to obtain a section of steel 5" x 3" x .25".

Robert Butler

Not an issue really. Factory setting 60 years ago would have been between dead flat and half a thou concave over the width of the faceplate. But after 60 years of wear, who knows?

This pic shows the basic principle of "diagonal" work holding jaw positions for the four jaw chuck.

But I like Duncan's idea to cut your piece of spring longer than required by say two inches, and  drill holes in the ends and bolt straight through to the faceplate . Machine the middle section and cut off the ends afterwards. Elegant in its simplicity and no chance of anything moving.

For interrupted cut on a large piece like yours, use low rpm, like backgear medium pulley.

Edited By Hopper on 25/04/2022 01:44:32

Edited By Hopper on 25/04/2022 02:02:42

That was my thought too, but then Felis said ' Removing most of the arc is simple in a 20 ton press. I re-arc truck springs in it without difficulty. This piece will be no different.'

Simply squeezing a leaf-spring between two flat anvils wouldn't flatten it permanently because the spring isn't taken beyond the elastic limit. But it could be straightened by bending it backwards over a fulcrum until the elastic limit is exceeded. Trouble is, bending a spring past the elastic limit damages it. Possibly it doesn't matter, for example piano wire can be wound into an effective coil spring without annealling and requenching.

My guess is Felis has access to a heap of scrap truck springs and hopes to use them as a cheap source of metal. I suspect it won't machine even if annealled. He's probably right that it's 5160, which I see on the web is tough stuff. Searching '5160 machineability' brings up discouraging statements like: While not easily welded or machined, 5160 steel can be heat-treated, annealed, and hot worked into shape. Leaded mild-steel (EN1APb) is much easier to machine than most other steels. (US equivalent, 12L14)

Dave

We do get a lot of questions where people are reluctant to fill in the gaps of info which they may not feel is relevant but actually would help quite a lot with the answer.

Is the intention to use this metal for practice? Is it a cheap source of steel which you feel you could use for multiple projects? Have you chosen this metal because it suits the end product? I sense from your guarded posts you don't really feel the intention is relevant, but it really honestly does help as when we know the intention we can assist with giving you information on the best way to achieve it.

This is all written with the best possible intentions to assist where possible.