Since we recently started carrying Dura-Bar® Cast Iron stock, we’ve had a lot of customers contact us with variations of the same question: “The material seems interesting, but what is it good for?”
That’s a good question, and we’re here to answer it! We spoke to the manufacturer for recommended projects as well as customers who have used this for real world projects to give you specific examples.
Dura-Bar® Ductile Iron vs Carbon Steel
In many ways, Dura-Bar® Cast Iron are most similar to carbon steels, so that’s what we’ll compare them to here.
There are two grades of cast ductile iron:
65-45-12: This grade has high amounts of ferrite and low amounts of pearlite. The composition of this grade provides excellent machinability, optimal impact resistance, and high fatigue resistance. Because of this, it is an excellent replacement for 1010, 1018, 1020, 12L14, 1212, and 1215 grades of steel.
80-55-06: This grade has a about a 50/50 mix of ferrite and pearlite. Therefore this grade is a bit less machinable than 65-45-12, but it is more durable and harder. It is well suited to replace medium carbon steels like 1040, 1045, 1060, 1141, and 1144.
|Tensile Strength (psi)||65,000||80,000||58,000||81,900||58,000||102,000||57,300|
|Yield Strength (psi)||45,000||55,000||31,900||45,000||31,900||60,900||34,100|
|Avg Hardness (BHN)||180||229||116||163||116||212||121|
|Machinability (1212 alloy=100%)||170%||95%||52%||56%||90%||83%||180%|
|Pieces/Insert Edge (relative tool life)||340||190||104||112||180||165||340|
Dura-Bar® Cast Iron comes in a third grade, G2, also known as Grey Iron. It is designed for applications requiring high wear resistance, vibration dampening, and good response to heat treatment. It is not ductile.
Cast Iron Inventory
Example Customer Projects
Vibration Damping – gears
Numerous customers have switched their gears from steel to Dura-Bar® Cast Iron. The graphite inherent in the material cushions vibrations travelling through the part. Because of this, the gears and other components that are exposed to heavy vibrations will be quieter and retain tolerances better. However, they are generally suited for lower stress applications. Specifically, parts made from G2 cast iron have about 10 times the damping capacity as steel. The two ductile grades have about 3 times the damping.
Besides being significantly quieter, gears manufactured from cast iron provide lower costs. The raw material typically costs less than steel and as it is easier to machine, that saves time and is gentler on your tools.
Problems solved: Excessive vibration, noise, wear resistance, cost
A customer was using 1045 carbon steel to make compressor rotors for a portable air pump and compressor. However, they were having issues with balance and high scrap rates on parts. So they decided to switch to a part made from 65-45-12 ductile iron. They reported reduced machining time, cheaper costs per part, and lowered tooling costs. Furthermore, they were pleased that their overall scrap rates dropped dramatically as well.
Problems solved: material quality, reduced scrap, and machinability.
Cylinder Block – Piston Pump
A customer was using sand castings to create cylinder blocks for their piston pumps. They were experiencing issues with porosity, so they decided to try switching to ductile iron. Specifically, they chose the Dura-Bar® Cast Iron because the patented Continuous Cast process used to manufacture them results in a fine grained structure free of porosity.
The customer reported high satisfaction, higher quality parts, and greater wear resistance and lifetime use, resulting in lower costs for replacements. In fact, they reported that their costs for the part dropped 33% after switching to ductile iron.
Problems solved: Quality, wear resistance, cost.
A customer was using Hot Rolled 1018 Carbon Steel to manufacture hydraulic manifolds, but they decided that their production time was too long and costs too high. Because of this, they switched to 65-45-12 ductile iron to make their parts. The performance was comparable to the steel, but manufacturing times were literally cut in half. The parts were easier and faster to machine, there was little to no deburring required, and less time spent changing worn tooling. This last note also resulted in lower total costs for the parts.
Problems solved: Machinability, pressure, cost.
For our last example, a customer was using Hot Rolled 12L14 Carbon Steel to manufacture a pulley used in the transportation industry. They decided that their costs and rate of part replacement were too high. So they switched to 65-45-12. Immediately their cost per part dropped by about 15%, as their pieces were made faster with less wear on their tools. Additionally, the life expectancy of the parts increased as the superior durability and surface finish of the Cast Iron Dura-Bar® meant fewer necessary replacement parts. They also were pleasantly surprised to discover their shipping costs dropped a bit since Dura-Bars® are about 10% lighter than comparable steels.
Problems solved: Production times, poor surface finish, cost, poor wear resistance.