The machinability of any material is very simply defined as the ease with which it can be machined. How machinable a metal is depends on the physical properties as well as the cutting conditions. Aluminum is more machinable than some of the other metals due to the fact it chips easily and can be relatively easy to shape.
"Chipping easily" means the material is more "free machining", and implies the cutting tool spends more time and effort cutting the work-piece, instead of chips it has just created. "Easy to shape" is all about speed. Aluminum can machine up to 3x to 4x faster than iron or steel. In fact, speeds over 10,000 RPM and feeds of over 200 ipm are more and more common in commercial machining.
As one of the materials with the highest level of machinability, aluminum is used in many different applications such as gears, knobs, camera parts, pipe stems and filters, radio parts, mobile phones, tripod fittings, machine parts and many more!
"Machining Aluminum requires special types of tools specifically designed for the task. We want tools that are very sharp, so we look to have a polished cutting edge, and often with no coating. This helps to create high shear forces to cut the material, but also helps prevent the material from sticking to the tool."
Luke Pollock - Product Manager
Walter USA, LLC. - www.walter-tools.com
"I wouldn't go as far as saying cutting aluminum is a cakewalk...but it is much more operator-friendly and tool-friendly than hardened steels or HSRA's, and hence often more cost-effective. If you're eyes are lighting up and you're getting excited to push your machine to its limits on this aluminum job – just remember a few things to be concerned with. Typical roadblocks to fun can be the "stickiness" aspect of material bonding to the cutting tool, chatter from using the wrong cutting parameters and finally, chip evacuation and chip volume wreaking havoc on the clean cutting process."
Tim Stapula - Marketing Manager
KPT Kaiser - www.bigkaiser.com
"When machining any material, the cutting tool needs to be matched with the part surface finish and tolerance as well as the machine tool and work holding. In high production aluminum applications, high-productivity tooling like Polycrystalline Diamond (PCD) or carbide, is typically the best solution in terms of final part cost and quality."
Bill Alexander - Manager, Field Marketing, Americas
Kennametal - www.kennametal.com