We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What Is a Hollow Chisel?

By Paul Scott
Updated May 17, 2024
Our promise to you
About Mechanics is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At About Mechanics, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

A hollow chisel is a woodworking tool for cutting single square holes in timber or, if used in an overlapping pattern, rectangular mortises. The tool consists of a hollow, square chisel with a rotating drill bit at its center. The tool is used in a dedicated mortiser machine or in a standard drill press with a special adapter. Downward force on the tool causes the chisel to cut out a square shape while the rotating drill bit clears all material from within the four sides of the cut through a port in the chisel body. Hollow chisels are available in a wide selection of single sizes or in sets.

Drilling round holes into timber is a fairly easy operation. Square holes, on the other hand, require special tools and techniques to achieve. Square openings or slots in timber are commonly known as a mortise and are used extensively to fit door hinges and locks and in the construction of mortise and tenon joints. These mortises can be cut out with a conventional hand chisel or a specialist tool known as a hollow chisel. The hollow chisel is basically a combination power tool bit used in a mortiser machine or, when paired with an adapter, in a regular drill press.

The hollow chisel consists of a steel tube of square cross section that has a scalloped cutting edge ground into its working end representing the chisel component. A flat edged rotary drill bit is positioned in the center of the hollow chisel with its cutting edge positioned slightly back from that of the chisel. During cutting operations, the square chisel body is clamped in a static position while the drill bit rotates within it. Downward force on the tool causes the sharp chisel to cut a square hole while the drill bit clears all the internal material out of the cut. This waste material is carried up the drill shaft by its flutes and is ejected from the tool via a port cut into one side of the chisel body.

This tool may be utilized to cut a single square hole or used in an overlapping pattern to cut longer or wider slots. The hollow chisel is made of hardened tool steel which holds a sharp edge well. It is available in a large selection of sizes either as a single item or as sets consisting of several consecutive or common sizes. The cutting edge on a hollow chisel is extremely sharp, and care should be taken when handling or storing it to avoid accidental contact with the edge.

About Mechanics is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
About Mechanics, in your inbox

Our latest articles, guides, and more, delivered daily.

About Mechanics, in your inbox

Our latest articles, guides, and more, delivered daily.