# Common Scrap Steel



## BronxFigs (Apr 23, 2013)

Most any engine I will build, will be from bar-stock, and steel scrap found in junkyards.  Much cheaper than castings...and if I screw up a part, some cursing, but,  no tears.

However, I'm a bit confused about hot rolled vs cold rolled steel, plate, and, bar-stock.

There is a difference, and I guess depending on what part of the engine you are using it for, you better pick the right steel.  But what steel is good for what part.

For example, crankshaft, con-rod....what steel?  Flywheel...does it matter?  Will one steel warp when turned?  Can internal tension be neutralized by heating and cooling before making chips?

This correct choices of material selection for each part has me very confused.  In a scrap-yard setting, is there an easy way to tell hot and cold rolled steels apart.  Everything is usually rusty, or, greasy.

Any rules-of-thumb?

Frank


EDIT:  After posting these questions, I realize they will be virtually impossible to answer without letting you know what parts of the engine the steel will be used for, stresses, working-engine vs. model engines etc.

I wish there was a reference section on this forum that listed engine parts, and the material choices for that part.  It would help me, that's for sure.  For example:  Crankshafts:  Use these steels....
                                                    Con-rods:  Aluminum, use these alloys....Steel, use these choices....
                                                     Valves, use these.....  Etc.
Frank


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## Philjoe5 (Apr 23, 2013)

Frank,
Several of the questions you have raised have been answered at various times on this forum.  My advice is to try to find machine shops that will sell drops.  Then you will know what you're getting and what the shop is using it for.  In my part of the world there are shops I can go to for help.  

If you can't find any shops, try fellow modellers at local shows.  I often get asked at shows, and try to provide any bits I can.

There are also on-line suppliers that provide stock and advice on applications but you have to consider shipping costs (Ouch!).

Scrapyards may sell cheaper, but a few wrong choices may cost you the savings or more in ruined tools.  Ask me how I know this.

Cheers,
Phil


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## Wagon173 (Apr 23, 2013)

Plus one to phil's advice.  New as I may be, I've destroyed a couple of tools also by chucking something I shouldn't have.  The cost of materials isn't really that bad if you order enough for a 3 or 4 projects all in one shot.  I'm also looking into buying a bunch of aluminum ingots and taking a crack at casting to offset the cost of bar stock and billets once I start moving onto bigger projects.  I'd like to start casting brass also for the custom plumbing for my submarine.  I'll leave steel well enough alone for now though.  If you're in the Bronx, you should be plenty close to several metal suppliers though.  If you want to go the online route, a neat place I found through this website is, http://www.budgetcastingsupply.com/


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## MachineTom (Apr 23, 2013)

In making an engine the cost of material is not that large, Steel being the cheapest of all. Since our engines are made first for sight, second for function. The fit and finish is often what first impress's anyone looking at your project, yourself first. To that end, if you know what you material is, you can choose feeds, speeds and tools that will work the best on that material. 

In addition to sites like ebay, MSC, Mcmater, I have found a place in CT Yarde metals. Online they have an area called Drop Zone, where they sell drops, odd sized cutoffs etc. Some stuff is just above scrap price, always limited supply that keeps changing. And a $75 minimum order. Most of the scrap yards around my town will not sell material at any price, and with no industry generating drops the pickings are slim. 

A suggestion would be buy some 12L14 round or hex material from whomever, and you will not want to fool with mystery metal again.  It is as strong as any mild steel, machines great, looks nice, but not as good as O1 drill rod, can be brazed, but is poor to weld. For flat steel A-36 is good stuff, to do anything with. 

Some years ago I bought 20 ft of 1" D SS, for like $30, it is a pig to work with, needs lube to machine well, drills poorly. But sure was cheap, about 4 ft left, good riddance. I do love the boat prop shafts that I get, free 304SS, not the easiest stuff to work, but it shines with only a turned finish, will look like a mirror if polished, threads well, but is tough on tools, and leaves stringy chips.


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## BronxFigs (Apr 23, 2013)

Wonderful to read all the caveats regarding scrap yard metals, and now that I read some of the warnings, buying correctly identified "drops" sounds like a good investment.  I have tried to machine some steels found at a scrap yard in Stamford, Connecticut, and it was terrible to cut, and ruined good carbide inserts.  So, what did I save?   Bar-stock is, or, can be cheaper for some non-critical parts. That's why I concentrate on scratch-built engines.  I need to use the metal sellers that you recommend.

I'll do some reading of past postings to find out what cranks, con-rods, and other critical parts are made from.

Thanks for all the great tips, and advice.

Frank


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## aonemarine (Apr 24, 2013)

Well im a bit of a wack job, i test what im going to cut with my pocket knife to give me an idea of how hard it is. Works out well for me...


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## Wagon173 (Apr 24, 2013)

aonemarine said:


> Well im a bit of a wack job, i test what im going to cut with my pocket knife to give me an idea of how hard it is. Works out well for me...



Lol, my knife cost me about what my drill press did.  I find that one of the wife's diamonds works well


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## thayer (Apr 24, 2013)

Bring a file along and save your knife and your marriage!


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## Woodster (Apr 24, 2013)

You could do what i did yesterday and just walk into a local workshop and ask for "Bar ends", and offer to pay. 9 out of 10 times you'll get it for free. I picked up about 3 kilos (6lb or so) of bright mild steel, EN3, EN24, a foot of 1"dia 303 ST/ST, some 3/4 hex EN1A, a few bits of Mild steel plate and a few Ali bar ends up to 1.5" dia. All for nuthin'. Worked out that i've saved myself about £50!

Next step is to try and design an engine, a)Only using the stock i've got, and b)Without any milling ops as i don't have a mill or milling atachment. Should be a laugh! I can do some milling type ops on the lathe, all be it dangerous!!


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## n4zou (Apr 24, 2013)

Philjoe5 said:


> Frank,
> Several of the questions you have raised have been answered at various times on this forum.  My advice is to try to find machine shops that will sell drops.  Then you will know what you're getting and what the shop is using it for.  In my part of the world there are shops I can go to for help.
> 
> If you can't find any shops, try fellow modellers at local shows.  I often get asked at shows, and try to provide any bits I can.
> ...



I quit that practice for that very reason. Scrap is a little less costly until you lose a cutting tool while cutting into a case hardened part of the scrap you purchased. I found a peace of heavy wall tubing I thought would be perfect for a cylinder. A 'hacksaw test' on an outside corner passed cutting it easily. I had no idea the interior surfaces had been case hardened. My boring insert was immediately destroyed when I attempted to cut it.


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## BronxFigs (Apr 24, 2013)

I still think a reference section, or chart, listing *critical* engine parts, and the alloy choices that can be used to machine that specific part would be very useful.  
Then I could look under: "con-rods" and find a listing of recommended Steel/Aluminum alloys that would work...ditto, valves, camshafts, cylinder material, piston choices, and recommended ring combinations, etc.  It's nice to have choices, and some substitutions.  This kind of concise reference, information would be invaluable to beginning builders like me.  It's tiresome to ask, and to answer that same questions over and over.  Searching the, forums sometimes, yields the information you need, but many times it doesn't.  Too many vague thread titles tell you little about what's in the thread.

Thanks for the suggestions.

Frank


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## Tin Falcon (Apr 24, 2013)

First of all relax and breath.  some plans specify metal needed others do not . We are building model engines. not the replacement for the space shuttle.

for many model engines strength is not a major factor with the exception of the crank shaft and crank disk and pin  you can make an engine out of plastic. I have done it. 



IIRC the machinery handbook suggests common uses for common alloys. 
the mcamaster carr web page and many other sellers will give properties and suggested use for metals.  

if you want a good guide on metals read here


AEROSPACE METALS - GENERAL DATA AND USAGE FACTORS  AFTO 1-1A-9

Avoid mystery metal . 

the most important factor for a home shop machinist is machinability. 


read here it may help as well. 
http://www.homemodelenginemachinist.com/f27/selecting-first-engine-build-15183/

Tin


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## Entropy455 (Apr 24, 2013)

There are several large metal recyclers near my house  one of which lets me pick through their scrap, and charges me only 20% over scrap value for what I take. The overwhelming majority of steel that I find is ASTM-A36 hot-rolled, which is good stuff!



Sometimes I purchase 50 pounds, sometimes I'll grab a half-ton. I scored about 100 feet of 4.5 round-bar a while back, and was very pleased!



The sad part is Im running out of room on my steel rack. I've got 150 feet of 1.25" round bar that I still need to put away, and I've got some large plate steel sitting behind the shop.



My wife thinks I collect too much steel. . . . . . . She's probably right. . . . .


Everything on this rack was purchased as scrap, for pennies on the dollar (including the steel to build the rack). I also picked up a good selection of 303 and 304L.


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## BronxFigs (Apr 25, 2013)

Thanks everyone.  Very helpful suggestions.  The reference links will give me all the information that I will need, I'm sure.

Frank


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## Wagon173 (Apr 28, 2013)

Tin Falcon said:


> First of all relax and breath.  some plans specify metal needed others do not . We are building model engines. not the replacement for the space shuttle.
> 
> for many model engines strength is not a major factor with the exception of the crank shaft and crank disk and pin  you can make an engine out of plastic. I have done it.
> 
> ...



I'll give a hundred bucks and a free bikini car wash to the first person to build a working model space shuttle...  My milkshake brings all the boys to the bench.


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## Tin Falcon (Apr 28, 2013)

Hey I only made a part for the space shuttle one a long time ago. 
Tin


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## ConductorX (May 1, 2013)

Wagon173 said:


> I'll give a hundred bucks and a free bikini car wash to the first person to build a working model space shuttle... My milkshake brings all the boys to the bench.


 
Estes Rockets sells a model space shuttle you can build, launch, fly and recover by parachute. I built and flew two of them. I also worked as a NASA contractor on the Space Shuttle External tanks in New Orleans.
1981 - 1991.

Estes Rockets
http://www.estesrockets.com/

I did a quick search and it appears they don't offer the Space Shuttle model any more.
Sorry

Found one on ebay
http://www.ebay.com/itm/Vintage-Est...Model_Kit_US&hash=item4ac3e17953#ht_38wt_1057

"G"


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## aonemarine (May 1, 2013)

I built the estes model space shuttle a long time ago. On its first launch the motor slid forward in the fusealodge and burned a hole the the side causing the shuttle to spin out of of controll and crash in flames.  Shortly after the real shuttle did about the same.....


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## Brian Rupnow (Jun 5, 2013)

Anything subject to a lot of rolling friction such as shafts, should be made from steel. Hot rolled or cold rolled mild steel is the preferred steel to use. Cold rolled is a very nice steel to use for shafting, as it has no mill scale on the outer diameter and requires no external machining, and the outer diameter is very accurately sized. Hot rolled steel has a nasty black scale on the outside that must be machined away, and it generally is supplied slightly oversized to allow for this. The best material for cylinders is grey cast iron, as the high carbon content in it allows a certain amount of self lubrication. Likewise, pistons can be made from grey cast iron for the same reasons, although with a fast revving engine the mass of a cast iron piston can cause oscillation problems, so it is acceptable to use aluminum for pistons. Anything which a shaft revolves in, another very high friction area is best built of bronze----however, many of us substitute brass, and while it isn't quite as good a bearing material as bronze, it is much better than "steel on steel". Grey cast iron can also be used for bearing blocks, again because of its high carbon content which helps with the lubrication. The main body of an engine which everything else bolts to can safely be built from aluminum with no problems. There is one caveat to remember though---Most home shops are not set up to weld aluminum, so if anything absolutely must be welded to it, then use mild steel. Connecting rods can safely be machined form 6061 aluminum, although it is preferred that they have a bronze or brass bushing in the ends. Crankshafts, whether they are built up or machined from solid should always be made of steel. Valves can be made from cold rolled steel or from drill rod. Flywheels should be as heavy as possible for a really smooth running engine, and consequently be made from mild steel or brass. Baseplates for engines can be made from aluminum. Camshafts should be made from steel. Cylinder heads which bolt on can safely be made from aluminum. Carburetor parts can generally be made quite safely from either brass or aluminum, except for any shafts such as throttle shafts which rotate should be made from steel.--Valve seats can be made from steel or brass. Any connecting linkages are generally made from steel, although in highly rust prone engines such as steam engines, brass is preferred. Cylinder rings for internal combustion engines should be machined from grey cast iron.-Brian.


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## va4ngo (Jun 5, 2013)

Thanks for an excellent summary of material usage brian


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## BronxFigs (Jun 5, 2013)

Thank you all for the responses and recommendations.  Now, it will be easier.

Frank


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## Wizard69 (Jun 6, 2013)

Estes rockets where one of the great blasts from my childhood.  I never had a lot of money growing up so each flight was a carefully planned expense.   After a bit the whole neighborhood (well two residents in driving range) wanted to watch to the extent the old retired guy actually purchased a few engines for me.   Since my rockets where on the small size it was easy to over engine them.   More than a couple flew completely out of sight one of which I found years later, still high up in a tree,  while hunting.  

Model rocketry is a different sort of hobby with a different sort of engine that leads to lots of excitement for a young kid.  




ConductorX said:


> Estes Rockets sells a model space shuttle you can build, launch, fly and recover by parachute. I built and flew two of them. I also worked as a NASA contractor on the Space Shuttle External tanks in New Orleans.
> 1981 - 1991.
> 
> Estes Rockets
> ...


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## Mainer (Jun 6, 2013)

I agree with others. If you figure out the cost per hour of the steel that may go into making a part, even high-cost material comes out pretty cheap. What other hobby lets you take $20 worth of raw material and spend 40 hours carefully machining it before you ruin it? 
	

	
	
		
		

		
			





  It may work out to 50 cents an hour for that expensive steel.


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## ConductorX (Jun 12, 2013)

Wizard69 said:


> Estes rockets where one of the great blasts from my childhood. I never had a lot of money growing up so each flight was a carefully planned expense. After a bit the whole neighborhood (well two residents in driving range) wanted to watch to the extent the old retired guy actually purchased a few engines for me. Since my rockets where on the small size it was easy to over engine them. More than a couple flew completely out of sight one of which I found years later, still high up in a tree, while hunting.
> 
> Model rocketry is a different sort of hobby with a different sort of engine that leads to lots of excitement for a young kid.


 
You can go above the "D" engines provided by Estes.  Once you get into the "E" and above they are usually empty reusable shells that you can use and reload.   I loaded up to an "F" engine.  I also witnessed a "J" launch where they had to call the local air traffic control for clearance.  It is a whole 'nother hobby from making model engines.

"G"


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## Wizard69 (Jun 13, 2013)

ConductorX said:


> You can go above the "D" engines provided by Estes.  Once you get into the "E" and above they are usually empty reusable shells that you can use and reload.   I loaded up to an "F" engine.  I also witnessed a "J" launch where they had to call the local air traffic control for clearance.  It is a whole 'nother hobby from making model engines.
> 
> "G"



Rocket engines are a form of internal combustion engines.   The big difference being the fuel also supplies the oxygen.   

In any event I'd did my rocket flying as a kid.   Never had the money to do the big rockets though they are indeed very interesting.


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## Reaxun (Jun 27, 2013)

I buy most of my metals at the metal mart where commercial and industrial customers buy there metal, they are crops or pieces left over from these orders that are too small for commercial sale EG: CR steel bar 1" dia 16" long and I pay 50% of new price, your local metal guys may do the same, I buy steel various grades, aluminum various grades, brass, bronze, copper, stainless. yes they don't always have exactly the piece I want but it really works pretty well and you then know exactly what you are getting, buying 1440 you get 1440... Make chips not more work


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## BronxFigs (Aug 2, 2013)

Brian, et al.

Thanks for the engine parts listing, and material choices for those parts.  It helped.  Now, I can start looking around for the correct materials, and hopefully make something that spins and pollutes the air.

Much obliged.


Frank


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## tornitore45 (Aug 3, 2013)

I see nobody addressed the warping side of your question.

Metal parts warp because the metal removed upset the equilibrium of internal stresses frozen inside when the billet is made.

Cold rolled steel has more internal stresses that hot rolled steel.

The proper way to make a part is to rough all the cuts leaving oversize and then finish.

The more asimmetrical is a part the higher the chance that it warps considerably.

All metals warp not just steel.


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## Tin Falcon (Aug 3, 2013)

If you really want to recycle keep in mind original use. And use for the same similar purpose. an old shaft from a printer can be used as a shaft for an engine. 
Cast aluminum can be recast to a different shape.  
if a piece was machined chances are it can be machined again. But beware hardened parts may tear up your tooling and cause frustration.
Tin


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## BronxFigs (Aug 13, 2013)

tornitore45 ...... warping issues.... thanks.   Never gave it a thought except for steel.

@ all who posted..... Thanks for all the information, caveats, and suggestions.



Frank


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## gerritv (Aug 15, 2013)

Reaxun said:


> I buy most of my metals at the metal mart where commercial and industrial customers buy there metal, they are crops or pieces left over from these orders that are too small for commercial sale EG: CR steel bar 1" dia 16" long and I pay 50% of new price, your local metal guys may do the same, I buy steel various grades, aluminum various grades, brass, bronze, copper, stainless. yes they don't always have exactly the piece I want but it really works pretty well and you then know exactly what you are getting, buying 1440 you get 1440... Make chips not more work



McKinnon Metals in Toronto does this. Not sure I got 50% off but $20 got me a lot of CR steel and 6061 Al off cuts.

Gerrit


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## Ripcrow (Aug 15, 2013)

Someone stated that they recently built an engine from plastic and just thought I would add that some Honda copies coming from china actually have a nylon crankshaft in them..never thought that nylon could handle that much pressure even on a 6 hp engine.


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## RCW (Aug 25, 2013)

Although I am a relative newbie, here are two things that I think I can pass along safely.

I am just starting to get into machining.  But I have had a shop of sorts for years, and that shop has often been frustrating, particularly finding stuff.  Now that I am a little older--and hopefully wiser--I am organizing everything, and it is time well spent.  A _paint-stick marker_ is worth its weight in gold. When I start buying materials, I will label each piece, so that a roughly-milled square block of hot rolled will not get picked for a piece needing a mirror finish.

Second--borrowed knowledge--I knew an old craftsman in a rural town who scrounged most everything. (He has no access to industrial remnants.) His machinery looked like the warehouse of a museum.  But he did beautiful work.  When he got ready to build something, he'd grab several possible candidates of scrap stock and head over to the grinder.  He could feel how hard the material was and usually get pretty close to the chemical composition by studying the sparks coming of the grinding wheel.  All the old blacksmith and machinist books had charts that showed what spark patterns various materials produced. I won't guarantee that new alloys wouldn't create some surprises, but his procedures are a starting point to eliminate at least some potential problems.  And most of us have occasions when we have little choice but hit the scrap bin.  How many suppliers are open at 3:30 Saturday afternoon?

That said, no doubt a good inventory of material _of labeled, known composition_ is by far the preferable route for most folks.

Bob


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