Cutting Aluminum Sheet Metal

Cutting Aluminum Sheet Metal

Aluminum sheet metal can be cutting with a variety of methods ranging from manual tools to highly advanced sheet metal cutting shears or fiber laser cutting machine. In this posting we will take a look at some of the most common types of cutting aluminum. When determining which method of sheet metal cutting is right for you ,you should take into consideration the factors of flexibility, speed, accuracy, finish, cost and automation.  There are a few basic properties of aluminum that affect how it can be cut.  One factor which helps aluminum is that it is a relatively soft metal.

Straight Bench Shears

Bench mounted shears are able to cut through relatively thick sheets of aluminum though their design will tend to limit your cuts to straight lines.  These types of shears lend themselves towards hobbyists and sheet metal shops doing custom or repair work.  Most machines are built well and will last a lifetime if the blades are kept clean and sharp.

Metal Band Saw

A carbide tipped or even standard steel blade will typically suffice for most gauges aluminum up to 1/4” thick, though you’ll have to move relatively slowly on the heavier stuff.  Putting a piece of particle board or plywood under the sheet metal is said to help with the process. This may help to pull heat away from the aluminum which has the  tendency  to absorb the heat. In addition to this masking tape on top of the metal will also help.   There ware various waxes and cutting oils which help keep the metal cool and allow the teeth to cut smoothly.

Power Metal Cutting Shears

Hand held micro shears are very effective for cutting aluminum sheet metal because they can be directed across the sheet with relative ease.  They do not generate any where near the heat of an angle grinder so melting of the metal is not a general concern.  Noise, sheet vibration and the finish edge quality are common draw backs of power shears.  Unless you are able to stabilize the work piece with clamps you should be familiar with how the tool is going to move itself and the sheet.

Water Jet cutting machine

Probably the preferred method for cutting intricate or thick aluminum the  water jet focus a very thin stream of water mixed with abrasives at  extraordinary  pressures and very high speed into the sheet metal.  This jet of water eats away at the metal and leaving a clean smooth edge.  Heat  dissipation  is not a concern with aluminum because unlike the laser systems the water jet is not melting the metal, meaning there isn’t a significant difference in the energy required to cut steel or aluminum.  Water jets are  surprisingly  capable of cutting very thick sheet metal, up to a few inches thick with very high accuracy.  Their main  advantages  are the finished edges, variety of materials and accuracy.

Punch Press machine for cutting, blanking and forming holes

Punch presses use shaped tools to knock out geometry in sheet metal.  Larger presses can be loaded with dozens of different types of tools for special cutting and forming.  They are not typically as quick as lasers but they offer the ability to stamp, roll and form the metal while cutting.  This allows for the formation of louvers, jogs,beads, and impressions which lasers cannot form.  They are  also  typically cheaper on the front end when compared to lasers however there are maintenance costs associated with the tooling.

Fiber Laser Cutting Machine

Modern lasers will be effective on cutting light to medium gauges of aluminum.  Because  aluminum  is able to more readily absorb heat compared to steel an industrial laser will require a large amount of power to melt the aluminum to allow the gas to blow through.  This is possible with modern equipment and cutting 1/2” thick aluminum plate is possible.  The challenge is as always the heat dissipation.