Machinability of Aluminum Round
First off, we're not machinists, but we can pass on what the metallurgists tell us. Use what you read below as a general guideline, but remember that we're not offering advice on your particular project. [Our lawyers wanted that last disclaimer to be longer and wordier, but you know what we mean!]
Here are some alloys that are available. We stock 6061 because we find it to be the best combination of machinability, corrosion resistance, weldability, and ductility. [That last one has nothing to do with fowl or tape; it just means "capable of being drawn out into a wire or thread."] We also carry 6063-T5 but it is softer, and more formable, and not designed for machining. If you need the other alloys below, just give us a call at 812.429.1634.
Screw Machine Stock
2011-This alloy offers the highest machinability of all aluminum rod. Excellent machinability; and relatively low cost make 2011 the most used screw machine alloy. Alloy 2011 is not recommended for welding or brazing, and it exhibits poor corrosion resistance. Typical applications are wiring devices and fittings, radio and TV components, optical parts, and electrical components.
2017-This alloy rates lower in machinability than 2011-but it provides slightly greater strength, better corrosion resistance, and easier welding than 2011. Alloy 2017 is also recommended for deep drilling. Typical applications are brake pistons, hinge pins, pulleys, and camera parts.
2024-This alloy has the highest tensile strength of all the aluminum screw machine alloys. It is recommended for parts that require consistent high strength. Welding characteristics and corrosion resistance are similar to 2017. Typical applications are aircraft parts, fasteners, couplings, hydraulic valve bodies, and orthopedic braces.
6061-This alloy doesn't machine as well as the other screw machine grades, but it does offer excellent corrosion resistance and excellent welding characteristics. It is also the most ductile of the screw machine alloys. Typical applications are hydraulic pistons, decorative hardware, door knobs, handrail fittings, and valves.
6262-This alloy is second only to 2011 in machinability. It combines strength, excellent weldability, and good corrosion resistance to make it the best all-around screw machine alloy. Typical applications are marine hardware, hydraulic pistons, marine diesel fillings, and couplings.
Non-Screw Machine Stock
1100-This alloy is 99% pure aluminum and, therefore, very poor in machining qualities. It does exhibit excellent electrical and thermal conductivity, excellent corrosion resistance, and outstanding welding characteristics. Typical applications are decorative parts, cold threaded parts, and welding rod.
7075-This is the highest strength aluminum rod or bar available. It also has machinability equal to 2017 and 2024. This alloy is not considered a screw machine grade because 7075 cannot meet screw machine straightness tolerances due to its high strength. This is a poor welding grade and has only average corrosion resistance. Typical applications are aircraft parts.