In the most basic of definitions, blade offset is the distance from the tip of the blade to the center of its shaft.
It’s also a measurement of the blade’s effective cutting width. The blade offset value is used in calculating the distance the blade must travel past a corner in order for the tip of the blade to reach the same point when its direction changes. This is most visible when cutting squares. If blade offset is set too low, corners will be rounded. If blade offset is set too high, your corners will bulge outwards.
For most applications, there is sufficient leeway in blade offset so that a slightly imprecise value will still yield an acceptable cut. The examples below are provided to illustrate a range of values and the effects they yield on a simple 1″ square.
As we can see above, the corners are slightly rounded until we get to 0.015″. At 0.020″-0.025″, it appears we’re at an ideal square. At 0.03″, the corners start turning outwards and by 0.05″ we start to see a pinwheel effect.
Now, this is all well and good, but let’s take a look at the remaining squares after the paper has been removed.
Unless I were doing very critical work, I wouldn’t be upset with any of the results until a blade offset of 0.035″ is reached. The corners are clearly beginning to protrude and my personal preference would be for an ever-so-slightly rounded circle rather than one with tails.
I hope viewing the results of this test helps to shed some light on this particular setting and the effects of different blade offset values. Thanks for reading!