Material problem

[abby]

I will just point out that cast iron bar is continuously cast through a graphite die as already stated , but , unlike steel it does not get rolled , drawn or have any other physical treatment except in some instances it may be pickled to remove scale.
In another post cutting fluids for cast iron were discussed but cast iron is machined dry and slow , can you imagine the filthy black sludge that would be produced with a coolant.
In my youth many of my pals (buddies) were apprentices at Alfred Herberts machine tool works , they would spend entire shifts machining cast iron and the black dust would penetrate through clothing right down to the skin , it would take a week of washing before they looked clean again.
Dan.

 

[Richard Hed]

You are lucky that works out OK for you.
Not materials, but cutting tools are what I buy surplus. We have a Raytheon Missile Plant in Tucson, and when they finish a contract run of a certain class of missile, the liquidate EVERYTHING connected to that program. The next program, which might start the following Monday morning, gets all new cutting tools, special jigs, etc, etc, etc. There are places in Tucson that pick up all these cutting tool bits, drills, etc, and sell them very cheap. I have drawers full of special inserts, reamers that are odd sizes,
and special drills and counterbores that were made for missile production, and have been sold for scrap, still sealed in their original containers. So that works out more favorably for me than buying unknown materials.

Whoa! That's really nice. (It's called "cost plus 15%, as a taxpayer, you should be angry about that.) When Boeing was in the Soviet of Washington, they had a surplus store which one could buy lots of stuff by the pound .
Got a lot of good deals. How often do they liquidate?

I have a bundle of carbide cutters that I don't have a holder for. They are that type that is a type of saddle. I keep looking for a reasonably priced holder, but no luck so far even tho' I see lots of the cutters for sale. When I get my mill set up, I'll try my hand a making one. Better to try to use these up-[-I don't even know where I got them, but I hve a lot. Also a bunch of large triangle flat carbides, but I DO know where I got those. Iworkt for a cost plus place--they had these carbides sitting in a cabinet for years. one day my boss told me to get rid of them. So I did (grin).

 

[William May]

Whoa! That's really nice. (It's called "cost plus 15%, as a taxpayer, you should be angry about that.) When Boeing was in the Soviet of Washington, they had a surplus store which one could buy lots of stuff by the pound .
Got a lot of good deals. How often do they liquidate?

I have a bundle of carbide cutters that I don't have a holder for. They are that type that is a type of saddle. I keep looking for a reasonably priced holder, but no luck so far even tho' I see lots of the cutters for sale. When I get my mill set up, I'll try my hand a making one. Better to try to use these up-[-I don't even know where I got them, but I hve a lot. Also a bunch of large triangle flat carbides, but I DO know where I got those. Iworkt for a cost plus place--they had these carbides sitting in a cabinet for years. one day my boss told me to get rid of them. So I did (grin).

It isn't the Raytheon company, but the U.S. Government. They have regulations that Raytheon is NOT allowed to use any tools that are NOT part of that current contract. So they can't hold over parts or tools they might need. The U.S. Government requires that everything connected to the missile be the latest iteration of the item. Raytheon would probably LOVE to use the stock they have on hand, and it would save them a lot of money and increase their profits. Instead, every missile order is as if it was the first and only production order, and they start from ground zero. They also face production penalties, so they have to order more cutters and tools than they need, to insure they can complete the work. I found out about all this from some engineers I know who work there. For them, it is a PITA.
I haven't bought anything in a couple of years, as I already have some drawers full of inserts and cutting tools. You would have to check around Tucson and see who is currently liquidating Raytheon's excess stock at the moment.

 

[kf2qd]

It's probably spun-cast - was done with the melt at too low a temperature - the "pour" proceed unevenly but in regular gulps and produced a helical pattern in the bar which also looks to be temperature shocked and possibly even improperly fused.
This process can also produce long epitaxially grained and corkscrewed core grain structure which is near impossible to drill straight.
I wouldn't use that material for anything important.
Normalising heat treatment might fix it - but I would still be suspicious of it's structural integrity.
Regards, Ken

Does this have a hole in the center of it? Spun Casting is a process for tubular castings. This material is probably continuous.

 

[Ken I]

Can you tell me how a spin cast mould works?

Here's a video of spin casting.

So you can see why a helical pattern can be formed.
Normally used for hollow bar but solid is also doable :-

Regards, Ken

 

[Richard Hed]

Here's a video of spin casting.

So you can see why a helical pattern can be formed.
Normally used for hollow bar but solid is also doable :-
View attachment 132032
Regards, Ken

The way that it appeaers to be poured, tht is, first by tht holding furnace, poured into the ladle which would mix it even more, and then from the ladle into the spinning die, it would appear to me that it wuld be well mixt. But the heat and cooling differnetials, I could not vouch for

 

[Thommo]

Altho' I have had similar experiences, I have also been able to get very low priced scrap material that has been easy to work with and did what I wanted it to do. For the low price, IMNSHO, it is worth the few times I get material that cannot be workt in comparison to the good stuff I can get. I live in a small town that has a lot of manufacturing in it and I get scrap prices from some of their rejects. I have a VERY good idea what the metal is because of that./ I don't live near a nuclear plant either. I have seen 2" X 4' X 10' pieces of scrap stacked 20 pieces high. Quite frankly it was unbelievable to see this, but I saw it with my own eyes. Naturally just one of those pieces would most likely crush my pickup truck so I didn't get one. Also, even at scrap prices, I probably could not afford it. However, there were pieces of scrap that had been laser cut outs and the guys were cutting them into smaller pieces. I bought some of those--they were only 1-1/2" thick. Ive been using them for a couple months now. They are high quality mild steel, easily cut on the lathe and mill. I'm using them to make the tools to make the tools to make parts with. A couple of those tools are plates that fit the nose of the lathe for ER collets.

I have ER-16; 25; 32; 40 and 50 to make. So far have managed only one which was poorly done because of a lack of a mill. I am getting that set up but will be a while till it's ready. Another project is a radius turner. I did, however, buy known metal of 3/4" drill rod to make the pins for the backing plates. I didn't want some unknown metal for that. I thimpfks that a blend of known and unknown metals works fine for me, and occasionally have to get rid of some piece of unworkable unknown material. I also buy a lot of quality material from Alcobra in Spokane.

I also get some free stuff from a machine shop in town. He does mostly farm related stuff which uses specialty metals and a lot of stainless. The specialty metals are generally very strong and tough steel but easily machined. The stainless? Godz, Thor and Wotan--you know what THAT is like but it is relatively easy to machine. and I get so much that if I mess it up I can just cut another piece and start over having learnt my lesson on whatever mistake is made (I hope).

Free stainless?? You lucky fella! I pay a fortune for mine.

 

[Richard Hed]

Free stainless?? You lucky fella! I pay a fortune for mine.

Yup. I have 2 or 3 pieces. One is bout 1-1/4 diam. The other two are either the same or very close. They are about 6-8' long. Do not know what kind, juust that it is used in farming, possibly something to do with water and irrigation, or maybe machines that handle food. I do not know what.

One type has absolutely no rust, but one of them has small amounts of rust but very little, as it is some form of SS. I know, I know, SS is not supposed to rust, but some types do indeed have thin formations of rust sometimes. Or possibly, it just looks and acts like stainless. I thimpfks I machined some just to see what it would machine like, and it did OK but I haven't made anything important yet. I am going to use two pieces for the Steam Valves on two Corliss/Rays. I made one valve years ago when I had much less experience, did not complete it, but it looks terrible, even tho' I believe I could resurrect it. But I have decided to change some of the dims and thread sizes to something more manageable in comparison to what is called out in the Ray drawings.

Where in Oz? I bet you DO pay a fortune even for a 6" piece.