Bump Cut

Getting a perfect miter joint often comes down to the smallest adjustments. In a recent shop tip, a simple “bump cut” technique showed how to fine-tune a miter cut by removing just the slightest amount of material for a tight, seamless fit.

The process starts by intentionally cutting the molding a little “heavy.” After making the initial 45° cut, the molding is lined up against a sacrificial fence and checked for fit. If the joint is still slightly off, the bump cut method allows for an ultra-precise adjustment without guessing.

Here’s the trick: the teeth of a miter saw blade are slightly wider than the blade body itself. With the saw turned off, the molding is gently pushed against the side of the blade, not the teeth. Then, when the blade is raised and lowered again, the difference between the blade body and the tooth width removes only a tiny amount of material. That small adjustment is often all it takes to create a crisp, tight miter joint.

Using a sacrificial fence makes the process even more accurate and helps support delicate moldings during the cut. Combined with the bump cut technique, it’s a simple but effective way to improve finish carpentry results and sneak up on the perfect fit every time.

Painted Bookcase with Classic Lines

See this technique in action, check out the Classic Bookcase project, where this bump cut method is used throughout to create clean, professional-looking miters and trim details.