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 Pug Mill?

By Leah Bloom
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.

The word "pug" means "to mix with water to make more elastic." A pug mill, then, is a machine used to grind and mix wet and dry materials, usually for clay, asphalt and similar compounds. Generally, a pug mill consists of a container and one or more rotating arms with blades or paddles on them. These act like a blender, producing a smooth, moist mixture that is easy to work with.

The pug mill has been in existence since at least the early 1800s. Initially, it was powered by horses or mules. Electric pug mills then became common in industry, though the basic design has remained similar.

Potters rely on these blenders to simplify the process of making and recycling clay. Clay can be mixed from scratch in a dedicated mixer or in a combined mixer/pug mill. Used clay can also be added to the mill to be re-incorporated. Once the clay is mixed, the mill is used to create a uniform consistency and moisture level. A good pug mill, or one with a vacuum component, can also remove nearly all of the air from clay, preventing bubbles from creating thin spots in the finished work.

Making asphalt in this mill generally requires closer supervision than does making clay. The blades of the mill must be very close to the sides of the container so that none of the particles added to the asphalt can escape mixing. Likewise, the mill must be filled precisely to ensure proper mixing of materials. Speed and length of mixing are also key. Asphalt mixed too briefly or slowly may not have time to homogenize, while asphalt mixed for too long or too quickly can lose some of its durability.

Pug mills vary widely in size, power, capacity and configuration. Some have helix-shaped mixing blades, while others use easily replaceable paddles affixed to a rod for mixing. In addition to those intended for mixing clay and asphalt, the mills can be made to mix chemical or agricultural compounds.

Individuals should take care when cleaning or repairing a pug mill or when removing pugged materials from the mill. Some materials are quite heavy and are better suited to a pug mill with an extruder than one with hand removal. Also, this mill can be a powerful machine and can cause serious injury if used improperly.

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
By anon1003514 — On Jul 10, 2020

You have a very nice photo of a donkey, but the article says horses and mules were used to turn pug mills. I don't think donkeys were used, as they are mostly smaller, lighter animals. However, there are very large donkeys, called mammoth donkeys. They were, and still are, very valuable because they are used to sire large mules on draft mares.

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.