They're all around us and protect us; they're an essential part of our way of life. We live among them, but we rarely pay attention to them. Have you ever wondered how they are so straight? The answer lies in a small tool that has barely evolved since its first models were used: the plummet.
In Ancient Egypt, plummets were already a common tool to find the sagittal axis — also called the right angle. This is how the walls of your home, of cathedrals, and even the Great Wall of China have been built. In the following guide, we'll tell you all you need to know to find the best plummet on the market.
- 1 Weekly newsletter with the best personal finance tips
- 2 Key Facts
- 3 Ranking: The best plummets
- 4 Shopping Guide: Everything you should know about plummets
- 4.1 What is a plummet exactly?
- 4.2 How are plummets used in construction?
- 4.3 How are plummets used in medicine?
- 4.4 What is the sagittal axis?
- 4.5 What are other uses for plummets?
- 4.6 What are the different parts of a plummet?
- 4.7 How should I use my plummet?
- 4.8 What plumbing techniques are there?
- 4.9 What are the different types of plummet based on their weight?
- 4.10 What is a laser plummet?
- 5 Shopping Criteria
- 6 Summary
- Traditional plummets have a string and a weight on one end, while laser levels can do the same job faster. These tools also feature a small clamping element called a nut.
- Plummets are frequently used in construction and architecture. As of late, they have also made their way into the medical field, where they are used to help patients in osteopathy and physiotherapy.
- Depending on its use, the weight of the plummet can range from 40 grams to 600 grams. This tool is mostly used to find the perfect vertical of a surface. Plummets are also used to measure the area of a body of water.
Ranking: The best plummets
While the plummet is a very basic tool that has changed very little throughout its history, you can find new, more resistant models made ith lighter materials. This means that choosing among all the options available on the market won't be easy unless you're a professional. We've selected the very best plummets to help you make your decision.
Shopping Guide: Everything you should know about plummets
You need to be familiar with plummets and their different uses in order to make an informed purchase. Despite their relative simplicity, these tools can be used in a wide array of situations. In the following section, you will learn all you need to know about plummets, which will help you pick the model that best suits your needs.
What is a plummet exactly?
Also called a plumb-bob, this tool is usually made of lead or treated iron (with zinc or chromium). It has a cylindrical or prismatic shape with a conical end. This weight is tied to a string from which it hangs, creating a completely vertical line. Indeed, a plummet helps find the perfect vertical plane.
Plummets are essentially the vertical equivalent of spirit levels. They have been used since ancient times to measure the depth of wells and water surfaces.
How are plummets used in construction?
These tools use one of the most basic natural laws, that of gravity, to find true verticality. That is why they are used in construction to know if a wall, panel, or column is vertical and perpendicular to the ground. This allows greater stability and weight distribution, two essential factors in any construction.
If a wall isn't plumbed correctly, on the other hand, it can lead to the whole structure collapsing due to the decrease in its general resistance. Less resistance and stability therefore mean the total destruction of any building.
How are plummets used in medicine?
These tools are a very important tool in other areas such as sports medicine, physiotherapy, or osteopathy. In these medical fields, traditional weight-and-string plummets are used to find what we call the sagittal axis of the body and correct back, spine, or posture problems.
In the case of medicine, the models used tend to be lighter and almost always come with a magnetic nut that helps to find the sagittal axis and place the plummet in less time, while preventing the weight from spinning.
What is the sagittal axis?
In anatomy, the sagittal axes or sagittal planes are the planes perpendicular to the ground and at right angles to the frontal planes, diving the body into two halves: left and right. The anatomical term "sagittal" was coined by Italian translator Gerardo de Cremona. Plummets are used to find this axis in the human body.
The sagittal axis is, in fact, a perfect reference vertical that theoretically divides the body in two through the central part, much like an imaginary plummet. In physiotherapy, professionals use this tool to find the axis, which allows them to correct bad postures, and muscular problems in osteotherapy.
What are other uses for plummets?
On top of the ones we just mentioned in the fields of construction and medicine, plummets are commonly used for other tasks. In fishing, for instance, stringless plummets are used to counterbalance and cast fishing lines to give them greater speed and sink into the water.
These tools have also been traditionally employed to build wells and to measure the depth of unexplored bodies of water. You can also make use of them in your home to hang decorative elements like paintings. Interestingly, some dowsers use plummets to find underground water reserves.
What are the different parts of a plummet?
Plummets are very basic tools composed of three elements: a weight, a string or braided thread, and a piece of wood that sits on the surfaces to help make measurements. These parts can be changed, so it is helpful to know what they are exactly:
- Weight: A lead weight (or any metallic material such as steel, aluminum, brass, or even plastic) that is cylindrical, conical, or a mix of both. Modern plummets made with mechanized and balanced metal are generally prismatic with a conical tip.
- Nut: Similar to a bobbin, this part can be made of wood, metal or magnetized metal. It must weigh the same as the lead weight and has a hole in its center.
- String: This rope, cord, or thread made of cotton or nylon passes through the hole in the nut and joins the two pieces. Nylon models are preferred in masonry, as they are more resistant to humidity and corrosion.
How should I use my plummet?
While these tools seem very basic at first glance, measuring verticality and horizontality isn't necessarily a walk in the park. Dropping the weight and letting the string tighten simply isn't enough. You must follow a series of simple steps to correctly use your plumb-bob and get accurate results:
- Unwind the string and free it from the nut.
- Place the nut on the surface of the element you want to plumb (wall, door frame, or other supports).
- Slide the string so that the weight descends to the lowest part of the plumbed element without touching the ground, and let the weight swing freely. The greater the distance between the nut and the weight, the greater the accuracy of the results.
- Once the weight stops, check its position.
- When the weight is practically supported on the element but doesn't touch it (a light of around 1 mm must pass through), the plumbing is correct and the element is perfectly vertical.
- If the weight is separated from the element, the verticality must be corrected by moving the element in the direction of the weight.
- If the weight rests on the element, the verticality must be corrected by moving the element in the opposite direction of the weight.
What plumbing techniques are there?
The plummet can be used as a measuring instrument in different construction situations. In that regard, several methods will allow you to measure the verticality of a surface. Here are three different techniques used in construction:
- Verticality control. This is the most common application. As explained in the previous section, the plummet hangs from the nut or a nail, and you must wait for the weight to stabilize. The string needs to be perfectly parallel to the wall, otherwise the latter is not vertical.
- Horizontality control. All you need to check the horizontality of a surface is your plumb-bob and a speed square. Simply hang your plummet close to the edge of one of the sides of the square, and check that the string is parallel. The perpendicular edge will allow you to control the horizontality.
- Projection of a dot. A dot is marked on the floor and needs to be projected onto the ceiling. You can make the tip of the weight coincide with the dot by placing the plummet over it. Once your tool stops moving, you can mark the dot on the ceiling by using its projection.
What are the different types of plummet based on their weight?
Plummets can range from small (as little as 30 grams) to large models (between 400 and 600 grams) depending on their application and the material in which they are built. The lightest tools are those used in medicine, especially in osteopathy and physiotherapy, while the heavy ones are designed for construction.
Even the heaviest plummets tailored to professional use are extremely affordable. You will need to regularly check that pointed models do not bend or become misaligned over time. If that's the case, you need to replace it immediately or it will affect your measurements.
What is a laser plummet?
Laser plummets are actually laser levels that include a function to measure verticality. While these models are ten times more expensive than traditional plummets, they have become extremely popular due to their ease of use. They are compact and have the same shape as a measuring tape.
We discuss these tools in greater depth in our article on laser levels. They run on batteries and project a laser beam, either straight or cross-shaped. Their main advantage over traditional plummets is their speed and ease of use, as well as their very high precision.
Plummets are very basic tools — little more than a metal weight attached to a string. However, these tools have evolved over time; they're now manufactured with better materials and offer new designs. In the following section, we'll look at a few criteria that you should evaluate when choosing your very own plummet:
The length of the string generally ranges from 13 to 40 feet. This length will actually determine the use of your plumb-bob. Medical models, for instance, feature shorter strings since they are not designed to measure long distances. In that case, we encourage you to opt for the shortest string possible to avoid discomfort.
Plummets for construction need longer and sturdier ropes. While you can always change it, you are advised to choose a quality one, with the necessary length. If possible, try and buy a nylon string; these are more resistant to wear, moisture, and corrosion than traditional cotton ropes.
The weight is the most important element of your tool. They are generally made from metal or plastic. Steel, aluminum, iron are common manufacturing materials, and the weight usually features a protective layer of zinc. You are advised to choose a ferrous metal model, since you will often have to use your plummet with a magnet.
The weight can range from 40 to 600 grams, and the use of your tool will partly depend on this. Weights of less than 200 grams are most suitable for the medical field, while construction professionals employ weights of 500 to 600 grams. Try to buy a mechanized weight with a conical tip if you can, as it will provide greater balance.
Metals — in particular treated steel — are the best materials for your plummet, and your string should be made from nylon. The best brands on the market generally offer tools with weights made with mechanized and balanced steel, with a zinc plating for greater resistance to corrosion and wear.
Mechanized steel is better balanced, which means that the accuracy of the plummet is improved. The tip of your tool will also be stronger and won't wear out or bend as easily, meaning it will have a longer useful life. Nylon is always the best material for strings, since it is more resistant and can withstand moisture better than cotton.
Some plummets come with accessories such as a plastic box for storage or a spare weight. Carpenter plumb-bobs feature several fastening systems, making them an excellent choice for working hands-free and more efficiently. Some models also include a magnet to the nut.
Many traditional weight-and-string plummets come with replacement parts. This isn't something you should overlook, because both the string and the weight will wear out over time. Having spare parts ready is a huge advantage and will definitely come in handy.
Depending on how you plan on using your plummet, you will want to have one or more specific features. For medical use in the fields of physiotherapy and osteopathy, we once again recommend light models with little weight and a fairly short string. Long ropes will bother you when measuring patients.
If you need a plummet for construction or DIY projects, then go for the complete opposite: a heavier weight and as long a string as possible. The manufacturing material doesn't really make much of a difference for medical plummets. In construction, however, privilege mechanized steel and strong nylon ropes.
Standard weight-and-string plummets are attached to the surfaces using the nut we have described earlier. This little element can be made of metal or wood. In some cases, the nut will feature a magnet in its lower part to allow you to work more easily. If you choose a magnetized model, check that it will support the weight.
Some of the latest models are shaped like pulleys. The string is located inside a plastic box, much like a measuring tape. These models usually have bindings for plaster and wood, hooks to hang on beams, and magnets to stick them to metal surfaces.
Designed to obtain the perfect verticality for surfaces, plummets have been around for thousands of years. They are the reason why our walls and columns are always straight, perfectly parallel to the floor. These tools are also very useful for finding the correct posture for the body and for measuring the depth of bodies of water.
A wide variety of plummets are available on the market, with different characteristics and sold within a fairly large price range. Throughout our article, you discovered our selection of the very best models out there, and you learned all there was to know about these tools. All that's left for you to do is buy the one that best suits your needs!
(Source of featured image: hongkit Wiriyachan: 82091348/ 123rf.com)