differences in types of forged steel
03-12-2007, 12:09 PM
#1
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differences in types of forged steel
i dont know much about this, but i know that forged parts are better than others... but whats the differences between like a 5140 and the other types like 4*** somethings?
03-12-2007, 01:37 PM
#2
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RE: differences in types of forged steel
Alloy used in the composition. 4340 is common for steel, it has good heat treating abilities. Aluminum alloys are crazy, but mainly the numbers once again have to do with the amount of silica, magnesium and other materials in the alloy. For the most part, companies trying to move volume do not offer tons of steel/aluminum types, they only offer what is best for most applications so you do not have to be a metallurgist to decide on cranks,rods and pistons.
03-13-2007, 12:22 AM
#4
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RE: differences in types of forged steel
4340 > 4130 > 5140
Those are the common ones you'll see for our parts. 4340 is the most common because that's what everyone wants. Any less, you might as well go cast. 5140 is also out there so they can use the term "forged" but offer a lower quality to save money.
Those are the common ones you'll see for our parts. 4340 is the most common because that's what everyone wants. Any less, you might as well go cast. 5140 is also out there so they can use the term "forged" but offer a lower quality to save money.
03-13-2007, 12:35 AM
#5
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RE: differences in types of forged steel
Here is a few paragraphs about it all. The hp levels and rpm levels in this is VERY conservative but this should at least give you a better understanding of the metal.
Engine Bearings and Crankshafts:
[hr]
What makes them [not] tick?
by Brendan Baker, Managing Editor
bbaker@babcox.com
The relationship between the crankshaft and main bearings is an integral one. Any metal-to-metal contact can have catastrophic results, and if the carnage was the result of improper finish or fitment, you'll likely get to work on your relationship skills again.
There are many analogies to explain how its parts relate to the engine as a human body. A crankshaft is like the spine of the engine because it controls engine power, albeit indirectly, through its stroke and displacement. The crankshaft is what transfers the up and down motion of the pistons and connecting rods into the more useable rotating motion that transfers power to the drivetrain. The crank also must lug the weight of the rotating assembly and be able to handle combustion loads. The engine bearings, too, must handle the loads from the crank and rotating assembly. So there is a great demand placed on both the crankshaft and engine bearings. We will review some of the things that make these two important components tick (or in some cases, not tick).[*]Selecting a crank
There are many styles and materials available when choosing an aftermarket crankshaft - whether or not you go for a stock or performance crank will depend on your application. If it is for racing, it will depend on what kind of racing and how much horsepower you have. If it's a performance street application you may decide to modify the stock crank instead of install a replacement. In most cases, for a stock "grocery getter" engine you will likely replace with OEM quality. Experts say that unless there is a good reason to upgrade it is best to stay with a stock crank.
The most common style of crankshaft is a cast iron crank found in many stock passenger car and light truck applications. While good for stock applications, these cranks are not well suited for high horsepower performance applications. Although some experts say you can run a stock cast crank if properly prepared in high performance applications, others ask why take that chance with an expensive high horsepower engine? Ultimately it is up to whatever you and your customer decide.
The range of materials found in today's crankshafts goes from nodular cast iron to 4340-alloy steel. The material that is best for you depends on the application. If you are building a stock engine "grocery getter" you won't need to upgrade to a high performance material, however, if you're building a performance engine, depending on the application, you may want to upgrade to a stronger more durable material.
The next step up from cast iron is the forged steel crank made from either 1038 alloy steel or 1053 alloy steel. The 1038 steel is very basic and contains just enough carbon for heat-treating and a little extra durability. A forged alloy steel crank is very durable but it too has its limits. The strongest crank with the best material is a 4340 billet steel crank, but it is not inexpensive. These cranks are primarily used on high-end racing applications.
When rpm and horsepower increase a cast iron crank will not be able to withstand the load, because as rpms increase so too does the load carrying capacity of the crank and bearings. So, especially in high-end applications, upgrading to high strength materials is a must.
The basic differences between a cast, forged or billet crank are its strengths. A cast crank is the easiest, least expensive way to manufacture a crank, and that's why most stock OEM cranks are made of cast iron. They are strong enough for the daily driver and generally will live forever in that environment, but when you start adding performance modifications there isn't enough strength to support the extra load. Typically a stock cast crank is rated at about 95,000-psi tensile strength, which is okay but not compared to the higher-end cranks rated up to 165,000 psi.
A typical stock or mild performance crank that is made from 1053 high-carbon alloy steel is rated at around 100,000-psi tensile strength (resistance to failure under high load). A stock cast crank can generally handle up to about 350-400 hp applications with a 5,000-5,500 rpm limit. A typical upgrade from the 1053 cast iron crank would be a forged 5140 steel shaft that has a tensile strength of around 115,000-psi. According to one expert, the "40" in 5140 represents the carbon level, which is approximately 40 percent in this case. It's a good upgrade from 1053 because it has less carbon (40% vs. 53%) and it contains chrome and silicone for improved durability.
Some experts recommend using a forged crank whenever power and rpm levels increase beyond mild performance levels. Forging increases the density of the metal as it is squeezed and compacted into shape, which results in a stronger core and better fatigue resistance. For use in high performance applications the material must have high tensile strength and high fatigue strength, which simply put, is the ability to resist breaking under load and failure due to repeated bending and twisting.
If you're building a big horsepower engine such as a 350-hp-plus small block V8 or a 450-hp-plus big block, you may want to consider upgrading to a forged or billet crank made of 4340 alloy steel, which is the strongest material available with a tensile strength of 140,000-165,000 psi. The 4340 billet steel crank has the highest fatigue strength (around 160,000-165,000 psi). The biggest difference in the various steel crank materials is the grain structure, heat-treating process and the mixture of elements. Cranks made of 4130 or 4340 for example, have higher amounts of chrome and nickel, which makes them stronger.
Engine Bearings and Crankshafts:
[hr]
What makes them [not] tick?
by Brendan Baker, Managing Editor
bbaker@babcox.com
The relationship between the crankshaft and main bearings is an integral one. Any metal-to-metal contact can have catastrophic results, and if the carnage was the result of improper finish or fitment, you'll likely get to work on your relationship skills again.
There are many analogies to explain how its parts relate to the engine as a human body. A crankshaft is like the spine of the engine because it controls engine power, albeit indirectly, through its stroke and displacement. The crankshaft is what transfers the up and down motion of the pistons and connecting rods into the more useable rotating motion that transfers power to the drivetrain. The crank also must lug the weight of the rotating assembly and be able to handle combustion loads. The engine bearings, too, must handle the loads from the crank and rotating assembly. So there is a great demand placed on both the crankshaft and engine bearings. We will review some of the things that make these two important components tick (or in some cases, not tick).[*]Selecting a crank
There are many styles and materials available when choosing an aftermarket crankshaft - whether or not you go for a stock or performance crank will depend on your application. If it is for racing, it will depend on what kind of racing and how much horsepower you have. If it's a performance street application you may decide to modify the stock crank instead of install a replacement. In most cases, for a stock "grocery getter" engine you will likely replace with OEM quality. Experts say that unless there is a good reason to upgrade it is best to stay with a stock crank.
The most common style of crankshaft is a cast iron crank found in many stock passenger car and light truck applications. While good for stock applications, these cranks are not well suited for high horsepower performance applications. Although some experts say you can run a stock cast crank if properly prepared in high performance applications, others ask why take that chance with an expensive high horsepower engine? Ultimately it is up to whatever you and your customer decide.
The range of materials found in today's crankshafts goes from nodular cast iron to 4340-alloy steel. The material that is best for you depends on the application. If you are building a stock engine "grocery getter" you won't need to upgrade to a high performance material, however, if you're building a performance engine, depending on the application, you may want to upgrade to a stronger more durable material.
The next step up from cast iron is the forged steel crank made from either 1038 alloy steel or 1053 alloy steel. The 1038 steel is very basic and contains just enough carbon for heat-treating and a little extra durability. A forged alloy steel crank is very durable but it too has its limits. The strongest crank with the best material is a 4340 billet steel crank, but it is not inexpensive. These cranks are primarily used on high-end racing applications.
When rpm and horsepower increase a cast iron crank will not be able to withstand the load, because as rpms increase so too does the load carrying capacity of the crank and bearings. So, especially in high-end applications, upgrading to high strength materials is a must.
The basic differences between a cast, forged or billet crank are its strengths. A cast crank is the easiest, least expensive way to manufacture a crank, and that's why most stock OEM cranks are made of cast iron. They are strong enough for the daily driver and generally will live forever in that environment, but when you start adding performance modifications there isn't enough strength to support the extra load. Typically a stock cast crank is rated at about 95,000-psi tensile strength, which is okay but not compared to the higher-end cranks rated up to 165,000 psi.
A typical stock or mild performance crank that is made from 1053 high-carbon alloy steel is rated at around 100,000-psi tensile strength (resistance to failure under high load). A stock cast crank can generally handle up to about 350-400 hp applications with a 5,000-5,500 rpm limit. A typical upgrade from the 1053 cast iron crank would be a forged 5140 steel shaft that has a tensile strength of around 115,000-psi. According to one expert, the "40" in 5140 represents the carbon level, which is approximately 40 percent in this case. It's a good upgrade from 1053 because it has less carbon (40% vs. 53%) and it contains chrome and silicone for improved durability.
Some experts recommend using a forged crank whenever power and rpm levels increase beyond mild performance levels. Forging increases the density of the metal as it is squeezed and compacted into shape, which results in a stronger core and better fatigue resistance. For use in high performance applications the material must have high tensile strength and high fatigue strength, which simply put, is the ability to resist breaking under load and failure due to repeated bending and twisting.
If you're building a big horsepower engine such as a 350-hp-plus small block V8 or a 450-hp-plus big block, you may want to consider upgrading to a forged or billet crank made of 4340 alloy steel, which is the strongest material available with a tensile strength of 140,000-165,000 psi. The 4340 billet steel crank has the highest fatigue strength (around 160,000-165,000 psi). The biggest difference in the various steel crank materials is the grain structure, heat-treating process and the mixture of elements. Cranks made of 4130 or 4340 for example, have higher amounts of chrome and nickel, which makes them stronger.
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