Machining For Dummies
Book image
Explore Book Buy On Amazon
Depth of cut (shortened to DOC) is the third leg of the cutting parameter stool. Think of it as "how big a bite" can the tool take. On a lathe, DOC is measured radially — a 0.125-inch roughing pass means you're taking 1/8 inch of material per side, determined entirely by the programmed toolpath (or, if using a G71 roughing cycle, by its D or U word).

On machining centers, the computer-aided manufacturing (CAM) system (and its operator) determines the depth of cut. Period. However, DOC here takes on a double meaning, as it is measured both axially (along the length of the end mill) and radially (on its diameter). For instance, using a 3/8-inch carbide end mill, you might "bury" the cutter along its entire 1-inch length and take light radial depths of cut (which, if performed in a circular manner, is known as a trochoidal toolpath), or you might take a heavy radial DOC and "step down" using relatively light axial DOC (most programmers consider this methodology old school).

DOC stands alone, in that whatever value you as a programmer (or as a manual machine operator) decide to take, no mathematical relationship exists between it and the feed rate and rpm. That said, it's important to recognize that heavy depths of cut may call for lighter feed rates and slightly slower rpm, while light depths of cut — because cutting forces are lower — allow more aggressive cutting parameters.

About This Article

This article is from the book:

About the book author:

Kip Hanson finished school in 1979 and got a job at a small machine shop in Minneapolis. Over the next thirty years, he worked his way up and eventually moved into manufacturing consulting and freelance writing. Today he has nearly 600 published articles across dozens of magazines and websites, covering everything from machinery and tooling to metrology and 3D printing.

This article can be found in the category: