10.2 COMMON WORKPIECE MATERIAL TYPES - BASIC MILL OPERATOR

One of the most common material types in a machine shop is aluminum. Two characteristics of aluminum are:

Very light weight and not prone to rusting

Mild steel is the most common material that machine shops use in machining. Mild steels are:

Typically on the soft side and easy to machine

When it comes to sheet and plate stock made from mild steels, you will hear the terms hot-rolled and cold-rolled used often. You can tell hot-rolled steel sheet or plate by its surface finish. The surface finish on hot-rolled steel is:

Crusty and scaled

It is not important to match the raw material you choose to machine the part from with the raw material call-out on the drawing.

False

Stainless steel is also known for its ease of machining.

False

When cutting aluminum, the Operator does not need to run the coolant system, based on the soft and gummy nature of the aluminum alloy.

False

The most common materials you will encounter when first starting out in a job shop are: mild steel, aluminum, stainless steel and alloy steel.

True

Alloy steels are stronger, tougher, and harder than mild steels.

True

Aluminum comes in a variety of alloys: 2000, 6000, and 7000 series.The most common aluminum alloy you will see in machine shops is 6061.

True

Cold-rolled steel is the same as hot-rolled steel, but put through additional processing.

True

Stainless steel is known for its toughness and non-rusting characteristics.

True