Uses for old brake discs.

Could you profile them and then use them as formers for boiler backheads etc ?

I still think the best place for them is in the bin!!

Bri

It would seem they are quite high quality and I wonder if some one who has a home smelter could use them and cast big lumps out of them.

Clive

Presumably the big lumps then go in the bin?

Regards,

Tony

Edited By Tony Jeffree on 01/05/2012 23:18:37

Two years ago I used a cut down brake disk as the main part of a rotating base for my grinder. This now forms the basis of my tool and cutter grinding equipment.

If you can whack one with a sledgehammer and it simply bounces off then that's a pretty amazingly tough grade of cast iron which is bound to be useful at some point if you do model engineering

I recall reading somewhere that someone used bike sprockets to make crankshafts for model airplane engines after he found out how tough they were,

Being made of forged steel they were extra tough and ideal for some of his work

Maybe they'd be a good material for bearings and bushes, circular and also square shaped ones?

Some of the old top lathe manufacturers used to boast about the toughness and longevity of their chilled cast iron beds.

Edited By Ady1 on 02/05/2012 01:45:44

One very simple use is as the base of an adjustable roller support stand for a bandsaw, used when cutting longer lengths of material to size or if you need an extra support on the bench or saw horse / tressle .

After turning off the hat from a vented disc, and very carefully turning both sides, a donation of adult beverages resulted in the "Iron Donut" being surface ground flat and parallel to half a thou. Lightly clamped to the mill table, the mill head can be reset with a DI in a couple of minutes. And yes Tony, the hat went in the bin.

Just a though but i have noticed some disc are crossed drilled ,i wonder if the drilling is accurate enough to be used to allow the disc to be used for indexing ?

IAN

Robert the top hat section, if parallel, and a suitable size, makes a good rim for a flywheel, I,v got a 6" flywheel made that way on one of my hot air engines. Ian S C

I can see the attraction of used disks as they are completely free, but at about 25£, even a new one should be an alternative. Actually, I can't see how they can make them, ship them, and sell them to the end user at that price

Having read this thread, when first posted, I happened to be looking for some material to use as a former for flanging a boiler end plate. At the same time, my 2001 VW needed new rear discs, so I asked the garage to retain one for me, so I could give it a go.

Having now started cutting the disk up, I can report that it seems to be cast iron. Drilling it produced fine silvery flakes (like the iron filings you used as a kid in magnetism experiments), rather than threads of swarf. My disc was worn to 9mm thick - might be useful as raw material for 16mm scale loco wheels!

If any one knows of a simple test to confirm it is cast iron, I'd like to hear from you.

Regards Tom

I have thought they might make a suitable source of CI for my Duchess cylinders, so melted a few in a salamander crucible. Had to get it hotter than the sun. The sparks and fireflies from what I guess is magnesium were enough to stop me trying again. I now melt off-cuts of meehanite bar which is exciting enough for me.

Best uses for these are probably at room temperature-chuck backplates/adapters would be my suggestion.

I used a HSS holesaw to cut donuts from worn out disks from my Nova some years ago and have since made excellent i.c.engine parts including piston rings from them.I'm now glad I kept them. Colin

By the sound of it you'v already done the test, fine granular bits on drilling, do you'r fingers get black when you handle the swarf? If yes it's cast iron thats my test, although some cast iron bar that I got does machine more like steel, but still dirty. Thats my bit, some one will have better description of identification. Ian S C

The material must be rather dependent on type of car and age. It can't be plain cast iron anymore but is probably alloyed and heat treated to remove the weakening carbon flakes of plain cast iron. Perhaps someone with a small sample living in a university town could trot along to their metallurgy department to lubricate a student into examining it.

As far as I know most cast brake rotors are gray iron, heat treated. Ford messed around with stamped steel heat treated rotors with riveted on aluminum centres in the 1970's. They were a disaster, many discs separated from the centres, causing total front end brake failure.

An excellent paper on technology of cast iron brake discs is at the link below. It has lots of technical detail on casting and heat treatments. Practices in Europe and ROW may vary.

**LINK**

JD

Thanks for the repsonses chaps.

Ian SC - yes you do get black fingers from the dust!

Don't think I'll worry about metalurgical testing - looks like others have found they work Ok as material for nornal cast iron components - and I wasn't intending resmelting them!

Regards Tom