Your Definitive Guide to M4 Screws: Understanding Size, Dimensions, and Applications

What is an M4 Screw?

An M4 screw is a metric screw with a nominal diameter of 4 millimeters (mm). It is typically made of steel, stainless steel, or brass, and has a machine thread pattern. The "M" in M4 denotes the metric designation, while the number 4 represents the nominal diameter in millimeters.

M4 Screw Size and Dimensions

The overall length of an M4 screw is measured from the top of the head to the tip of the thread. Standard lengths range from 6mm to 50mm, although custom lengths are also available.

The head diameter of an M4 screw is approximately 7mm, and the thread pitch is 0.7mm. The thread pitch refers to the distance between adjacent threads on the screw.

Conversion Table: Imperial to Metric

For those familiar with the imperial system, here is a conversion table for M4 screws:

Types of M4 Screw Heads

M4 screws come with a variety of head types, each suited for different applications:

• Phillips head: The most common type, with a cross-shaped recess in the top of the head.
• Slotted head: A traditional head with a straight groove cut into the top.
• Hex head: A hexagonal head that can be tightened using a hex key or wrench.
• Button head: A low-profile head with a rounded top.
• Socket head: A head with a hexagonal recess that can be tightened using an Allen key.

Applications of M4 Screws

M4 screws are used in a wide range of applications, including:

• Electronics: Securing circuit boards, plastic enclosures, and other electronic components.
• Furniture: Assembling furniture, attaching handles and knobs, and joining wood panels.
• Appliances: Installing components in appliances such as refrigerators, ovens, and washing machines.
• Automotive: Securing interior parts, mounting accessories, and fixing body panels.

Common Mistakes to Avoid

When using M4 screws, it is important to avoid the following common mistakes:

• Overtightening: Applying excessive force when tightening an M4 screw can strip the threads or damage the material it is being attached to.
• Incorrect head type: Using the wrong head type for the application can make it difficult to install or remove the screw.
• Mixing different materials: Using M4 screws made of different materials (e.g., steel and brass) can lead to corrosion or galvanic reactions.
• Using the wrong length: Choosing a screw that is too long or too short can affect the strength and functionality of the joint.

Pros and Cons of M4 Screws

Like any type of screw, M4 screws have their own advantages and disadvantages:

Pros:

• Strength: M4 screws are relatively strong and can withstand moderate loads.
• Versatility: M4 screws are available in a wide range of lengths and head types, making them suitable for various applications.
• Cost-effectiveness: M4 screws are generally inexpensive and easy to find.

Cons:

• Size: M4 screws are relatively small, which can make them difficult to handle or tighten in tight spaces.
• Durability: M4 screws can be prone to corrosion if not properly protected.
• Load capacity: M4 screws have a limited load capacity compared to larger screws.

FAQs

1. What is the torque setting for an M4 screw?

It depends on the material and application, but typically between 1.5 and 2.5 Newton-meters (N·m).

2. Can I use an M4 screw in wood?

Yes, but it is recommended to use a pilot hole to prevent splitting the wood.

3. What is the thread length of an M4 screw?

Typically about 1.5 to 2 times the diameter, or 6 to 8mm.

4. What is the difference between M4 and #4 screws?

M4 and #4 screws are not interchangeable. M4 screws are metric, while #4 screws are imperial. #4 screws have a nominal diameter of 0.112 inches, which is slightly larger than 4mm.

5. Can M4 screws be reused?

Yes, but it is important to check for any damage or wear before reuse.

6. How do I remove a stripped M4 screw?

Use a screw extractor or drill out the head and replace the screw.

Call to Action

Whether you are a DIY enthusiast or a professional in need of reliable fasteners, M4 screws are a versatile and cost-effective solution for a wide range of applications. With proper understanding of their size, dimensions, and applications, you can confidently use M4 screws to secure your projects and ensure their long-lasting performance.