A torpedo level is a tool that determines whether a surface is perfectly level (horizontal) or plumb (vertical). Some torpedo levels can also indicate whether a surface is angled correctly.
Torpedo level designs might vary, but the one constant is the presence of the glass vials filled with colored (usually fluorescein) mineral spirits or alcohol. The glass tube is only partially filled, so you’ll see a bubble inside the vial. This bubble indicates if the surface is level, plumb, or if it is set at a correct angle.
There are many different types of spirit levels, and the torpedo level is just one of them. But what makes it different from other types of spirit levels?
The answer is its size. Most torpedo levels are only 9″ in length (the Milwaukee torpedo level we have reviewed above is an exception). These tools typically have aluminum, ABS plastic, or rubber frames. Their ends are tapered, and because of their compact size, they can fit into tight spaces. You can also carry them around inside your vest, jacket, or pants pocket.
Torpedo Level Buying Guide
Let’s take a look at the essential features you should consider when buying a magnetic torpedo level.
Spirit levels determine whether a surface is level or not, so the first thing you should consider when looking for a torpedo level (or any type of level, for that matter) is whether it is accurate or not. Look for levels with a vial accuracy of 0.0005 inches/1 inch (0.5 millimeters/1 meter or 0.29°).
Most torpedo level frames are made of die-cast or billet aluminum, while others have an ABS plastic body with aluminum railings. All materials are durable and can withstand the rigors of the jobsite, but one material can be better than the other in some aspects.
Aluminum, for example, is durable and resilient. It has a remarkably high strength-to-weight ratio and is amazingly lightweight. Aluminum torpedo levels are also corrosion-resistant. But you have to be careful not to slam it against a hard surface to prevent dents and scratches from developing on the surface. Moreover, many aluminum torpedo levels are pricier than plastic frames.
ABS plastic is another common material used as a torpedo level housing. Plastic torpedo levels are marginally cheaper than aluminum ones, and they are also shock and scratch-resistant. But these tools eventually warp over time, thus affecting the level’s accuracy. They are also non-biodegradable and are not suitable for use in the harshest jobsites.
Highly Visible Mineral Spirit
Mineral spirits are dyed with a colorant (usually fluorescein) to make the liquid inside the vial highly visible in any jobsite. Most dyes are either green or yellow, but a few torpedo levels have their mineral spirits dyed bright blue. When choosing the right torpedo level, make sure that the color is highly visible in poorly lit workplaces or even under the sun. Make sure that it also offers a good contrast to the bubble for greater accuracy.
Many torpedo levels come with a magnet at the base. This allows the user to place the tool on a metal pipe or shelf to determine plumb or angle hands-free. Choose a torpedo level with a set of strong magnets if your job involves a lot of determining if a metal pipe or bar is plumb or angled correctly.