Cast iron 250

I was wondering if any one has ever used cast iron 250 as its the only cast iron that most of the big boys supply. I'm use to Meehanite, but due to cost, as I need a 50mm diameter x a meter length, I thought I'd give it a try, but looking at the on line specification, it says it is a fine grain cast iron which can be polished and used for gears and cams, which I'm hoping will be perfectly okay for the cylinder liners I want to produce. Any experiences, good or bad would be appreciated. Thanks

It is the metric equivalent of the old imperial Grade 17. I have turned and milled a lot of Grade 17 for bevel gears, hollow pistons, piston rings and an IC engine cylinder liner. It machines beautifully and it is easy to get a good finish. I haven't tried surface grinding, but it produces a very nice finish when cylindrical grinding. I assume that it is what I have in stock for the liners for my traction engines, and I expect it to be fine in that application.

Andrew

The majority of teh CI I have used comes from College Eng and they list it as "Grade 17 (250) " and it has all been nice to machine.

I have carved steam cylinders out of solid blocks, made cylinder liners for slow reving Hit & Miss engines as well a shigher reving 4-stroke aero engines from round bar and also used it for pistons on glow engines that rev higher still plus plenty of piston rings. It laps and hones well.

J

PS what are you going to do with a meter of bar ? Radial or V8?

Edited By JasonB on 23/12/2014 19:04:01

Hi. Jason.

Its a nine cylinder rotary this time. Glad to learn that 250 is decent stuff, I was feeling a bit apprehensive as the first bar they sent me was hot rolled mild steel and its taken me several days to get them to accept that I know the difference!

"Meehanite" is a trade name like "Hoover" that applies to several grades of cast Iron. I, and others, are guilty of using it as a shorthand for ductile cast iron.

Neil

Meehanite used in the ME hobby is certainly not a ductile iron as it has a flakey/granular structure, SG (spheroidal graphite)iron is the ductile one and I've never heard that refered to as Meehanite and you would have a job snapping piston rings if the iron were ductile.

J

Edit. Meehanite quality SG iron is made but usually when one sees Meehanite mentioned in our circles it is the grey iron

Edited By JasonB on 24/12/2014 18:36:43

There are many types of Meehanite, including ductile:

www.meehanitemetal.com

Neil