Customizing Screws: Cutting Down To Size

Cutting a screw to size can be a challenging task, especially if you don't have the right tools or know-how. Whether you're looking to shorten a screw that's too long for your project or need to remove a stripped screw, it's important to know how to cut it safely and effectively. In this guide, we will cover everything you need to know about cutting screws, from choosing the right tools to taking the necessary safety precautions. We will also discuss the different types of screws and provide step-by-step instructions on how to cut them down to size using various methods.

Cutting wood screws

Wood screws are designed to attach two pieces of wood together. They have threaded shanks with either coarse or fine threads, and they taper to a point. They are designed to go into pilot holes drilled into the wood, although sometimes they can be driven into soft wood without these holes.

If you find yourself with a wood screw that is too long, you can cut it down to size. This is often easier than making a trip to the hardware store. Wood screws are easier to cut than machine screws because you don't have to worry about damaging the threads.

In most cases, all you need is a pair of heavy-duty pliers or wire cutters, such as linesman's pliers, diagonal pliers or flush-cutting pliers. Simply snip off the end of the screw to the desired length. Be aware that the main part of the screw and/or the cut-off tip may go flying once the pliers break through. You can contain the pieces (so you don't have to search for them) by sticking the pliers inside a box or bucket or laying a rag over the tool before making the cut.

If you don't have wire cutters, you can use a hacksaw, or a jigsaw or reciprocating saw with a metal-cutting blade. Power saws cut much faster and with less effort, but a hacksaw is generally easier to control. Reciprocating saws tend to jump around, and jigsaws need a flat or straight surface to rest on during the cut.

If you use a power saw, there are a few tricks to get a straight cut:

• Thread a nut onto the screw, stopping anywhere on the head side of the cutting line.
• Wrap masking tape around the screw shank so one edge of the tape is on the cutting line. If you wrap the tape a few times and keep the edges aligned, it will form a single band that marks a straight line all the way around the screw. Follow the edge of the tape with the saw blade throughout the cut.
• Clamp the screw in a vise or secure it to a workbench with a clamp.
• Cut the screw as straight as possible. When you're done cutting, unthread the nut from the screw, removing it from the cut end. This will realign any threads that were misshapen by the saw blade. You may need to use a wrench or pliers and a screwdriver to make the last few turns of the nut.

Cutting machine screws

Machine screws are a type of fastener with a straight (non-tapered) shank and fine threads. They are designed to fit into nuts or threaded holes with matching threads. As the fit of the threads is precise, any damage to them can prevent the screw from fitting together properly. Therefore, it is important to take care when cutting machine screws to preserve the threads.

Using a Hacksaw or Reciprocating Saw

For larger machine screws that are too big to cut with wire strippers, you can use a hacksaw, jigsaw, or reciprocating saw with a metal-cutting blade. A hacksaw is a general-purpose metal-cutting saw defined by its blade length, which can vary from 6-inch mini hacksaws to heavy-duty 24-inch tools. A reciprocating saw, on the other hand, is a powerful tool that mimics the action of a handsaw and can cut through metal, wood, plastic, and composites with the right blade.

When using a hacksaw or reciprocating saw to cut machine screws, there are a few tricks to help preserve the threads:

• Thread a nut onto the screw, stopping anywhere on the head side of the cutting line.
• Wrap masking tape around the screw shank so that one edge of the tape is on the cutting line. This will form a single band that marks a straight line around the screw. Follow the edge of the tape with the saw blade when cutting.
• Clamp the screw in a vise or secure it to a workbench with a clamp.
• Cut the screw as straight as possible. After cutting, unthread the nut from the screw, turning it a few times with a wrench or pliers if necessary. This will realign any threads that were misshapen by the saw blade.

Using Wire Strippers

For small machine screws up to standard size #10 or metric size M5 (5mm), it is best to use a pair of multi-purpose wire strippers. These tools have precisely sized threaded holes for cutting machine screws. To use:

• Open the wire stripper jaws until the screw-cutter holes are fully open and form full circles.
• Thread the screw into the appropriate hole from the front side of the tool, using a screwdriver if necessary.
• Turn the screw until it reaches the desired length.
• Squeeze the tool's handles to cut off the screw, then unthread the screw from the hole.

Using Bolt Cutters

Bolt cutters are another option for cutting machine screws, especially if you need to cut through other materials such as chains, padlocks, or rebar. They come in a variety of sizes, from small one-handed cutters to large two-handed cutters, and can generate a significant amount of cutting force. When using bolt cutters, it is important to position the jaws so that the bolt is closer to the base of the jaws than the tip, as this provides greater cutting force. However, bolt cutters can be bulky and may not be suitable for small screws or tight spaces.

Using bolt cutters

When using bolt cutters to cut a screw, it is important to choose the right size for the job. You should also ensure that the jaws of the bolt cutters are sharp and in good condition. Here is a step-by-step guide on how to cut a screw using bolt cutters:

• Place the screw in the jaws of the bolt cutters, ensuring it is positioned correctly.
• Squeeze the handles of the bolt cutters to cut through the screw. Use slow, steady pressure and apply even force to the cutters.
• Use a file or sandpaper to smooth the cut edge.

While bolt cutters are a quick and efficient way to cut screws, they may not provide the same level of precision as other methods. Additionally, they can leave a rough or sharp edge on the screw, so it is important to take the necessary safety precautions, such as wearing gloves and eye protection.

It is also worth noting that bolt cutters are bulkier tools, so they may not be ideal for small screws or tight spaces. In such cases, other cutting tools like wire cutters or a hacksaw may be more suitable.

Using a hacksaw

First, you need to clamp the screw securely in a vice. Ensure that the screw is tightly secured and cannot move or rotate. If you do not have access to a vice, you can use a pair of locking pliers or a sturdy clamp to hold the screw in place. Just make sure that whatever method you use, the screw is firmly held and cannot shift during the cutting process. With the screw securely clamped, you can begin the cutting process.

When using a hacksaw, it is important to use a steady and controlled motion. Start by positioning the hacksaw at the desired cutting point on the screw. Hold the hacksaw at a slight angle, with the blade tilted slightly forward, and apply gentle pressure as you begin to cut. Use a smooth, back-and-forth motion, allowing the teeth of the blade to do the work. Do not apply too much force, as this can cause the blade to bind or break. Take your time and let the saw do the cutting for you.

Keep a steady rhythm and apply light pressure. You may need to adjust the angle of the blade slightly as you cut to ensure a straight cut. Continue cutting, maintaining a slow and consistent pace. Cutting too quickly can generate excessive heat, which could potentially damage the screw and blade. Take breaks if necessary to avoid overheating the blade and always wear gloves to protect your hands from the sharp edges of the screw and saw blade.

Once you've cut through the screw, use a metal file to smooth the cut end. Remove any burrs or sharp edges by filing in one direction, away from the cut end. This will create a smooth and safe finish to your newly sized screw. Finally, clean the freshly cut screw using a brush or cloth to remove any metal shavings or debris. This ensures your screw is ready for its intended use, free of any potentially damaging particles.

Using a reciprocating saw

Firstly, it is important to prioritise your safety. Always wear protective gear, such as safety goggles and gloves, to shield yourself from metal shavings and the blade of the saw.

Before you start, ensure you have the right blade for the job. For cutting metal, you will need a blade made of bi-metal or carbide. Additionally, the blade's length should only be a couple of inches longer than the depth of the cut to reduce 'waggle' during use.

Now, you can begin the cutting process. Clamp the screw in a vice to keep it steady and secure. This step is crucial to ensure your safety and achieve a precise cut. Once the screw is clamped down, use a metal-cutting blade in the reciprocating saw. Turn on the saw and slowly guide the blade through the screw, following a marked line if you have one. Remember to use a slow, steady motion and apply even pressure to the blade.

After you have cut through the screw, remove it from the vice and use a file or sandpaper to smooth out any rough edges. This step is important to ensure the screw is safe to handle and easy to thread into place.

Finally, always exercise caution when working with power tools and remember to unplug the saw when you are finished. By following these steps, you can effectively cut a screw down to size using a reciprocating saw.

Frequently asked questions