RE: What is the difference between aluminum and stainless steel
aluhm > 02-01-2018, 01:37 AM
Steel and aluminum are the two most popular materials used in both metal spinning and metal stamping. Each material has a defined and distinct set of characteristics that make it the right – or the wrong – material for the job. When selecting material for your spun part it’s important to consider the following: cost, the shape of the spinning, and most importantly the end application.
Aluminum vs Steel Cost
Cost and price are always an essential factor to consider when making any product. The price of steel and aluminum is continually fluctuating based on global supply and demand, fuel costs and the price and availability of iron and bauxite ore; however steel is generally cheaper (per pound) than aluminum (see galvanized vs stainless for more info on steel). The cost of raw materials has a direct impact on the price of the finished spinning. There are exceptions, but two identical spinnings (one in aluminum and one in steel) the aluminum part will almost always cost more because of the increase in the raw material price.
Strength & Malleability of Steel vs Aluminum
Aluminum is a very desirable metal because it is more malleable and elastic than steel. Aluminum can go places and create shapes that steel cannot, often forming deeper or more intricate spinnings. Especially for parts with deep and straight walls, aluminum is the material of choice. Steel is a very tough and resilient metal but cannot generally be pushed to the same extreme dimensional limits as aluminum without cracking or ripping during the spinning process.
Corrosion Resistance of Steel and Aluminum
While malleability is very important for manufacturing, aluminum’s greatest attribute is that it is corrosion resistant without any further treatment after it is spun. Aluminum doesn’t rust. With aluminum there is no paint or coating to wear or scratch off. Steel or “carbon steel” in the metals world (as opposed to stainless steel) usually needs painted or treated after spinning to protect it from rust and corrosion, especially if the steel part will be at work in a moist, damp or abrasive environment.
Weight Differences in Steel and Aluminum
Even with the possibility of corrosion, steel is harder than aluminum. Most spinnable tempers and alloys of aluminum dent, ding or scratch more easily as compared to steel. Steel is strong and less likely to warp, deform or bend under weight, force or heat. Nevertheless the strength of steel’s tradeoff is that steel is much heavier /much denser than aluminum. Steel is typically 2.5 times denser than aluminum.
The final application of the part will ultimately determine which material the part would be spun from, balancing all the limitations and advantages of each material. On some spinnings it’s an easy call, while others are a tougher decision. If you or your engineering departments are on the fence with a steel vs. aluminum dilemma, please contact the authority on metal spinnings at Wenzel Metal Spinning, Inc. and we will be happy to provide you with our expert opinion and supporting information. Additional information about steel and aluminum can be found on our materials page.