Double Action OTF Knife Blueprints

Double action OTF (out-the-front) knives have long been an intriguing and practical tool for many enthusiasts and professionals alike. These versatile cutting instruments are known for their unique and innovative mechanisms, allowing users to deploy and retract the blade with ease. The double action feature, coupled with their compact design, makes them a popular choice for a variety of applications.

The intricacies of these knives are not just skin-deep, as their internal mechanisms are what truly set them apart. A well-crafted double action OTF knife requires precision and attention to detail, which is where blueprints play a critical role. These detailed plans ensure that every component of the knife is accurately designed and assembled for optimal functionality.

Whether you’re an experienced craftsman or a newcomer to the world of knife-making, this comprehensive guide will delve into the complexities of double action OTF knife blueprints. Get ready to embark on a journey that will leave you with a newfound appreciation for these remarkable tools and the knowledge to craft your very own masterpiece.

Contents show

Understanding Double Action OTF Knives

Definition and Mechanism of Double Action OTF Knives

Double action OTF knives are a type of switchblade that allows the user to deploy and retract the blade with a single button or lever. The “double action” term refers to the dual functionality of the opening and closing mechanism. These knives typically utilize a spring-loaded system, which enables the blade to move in and out of the handle with minimal effort from the user.

Advantages and Disadvantages of Double Action OTF Knives


  1. Quick and easy deployment: The spring-loaded mechanism ensures rapid deployment and retraction, making it a convenient tool for various tasks.
  2. Safety: The blade remains securely inside the handle when not in use, reducing the risk of accidental injuries.
  3. Compact design: Double action OTF knives are often designed with a slim profile, making them easy to carry and store.


  1. Legal restrictions: Due to their automatic nature, double action OTF knives may be subject to strict regulations in certain jurisdictions.
  2. Maintenance: The complex internal mechanisms require regular maintenance to ensure optimal functionality and longevity.
  3. Price: High-quality double action OTF knives can be expensive, especially if they are crafted from premium materials and components.

Common Uses and Applications

Double action OTF knives are versatile tools that can be used for a wide range of tasks, including:

  1. Everyday carry (EDC): Their compact design makes them an ideal choice for EDC enthusiasts who value quick and easy access to a cutting tool.
  2. Camping and outdoor activities: The rapid deployment and retraction capabilities make these knives a reliable companion for various outdoor tasks, such as cutting rope or preparing food.
  3. Tactical and self-defense situations: The swift and smooth action of a double action OTF knife makes it suitable for use in high-pressure situations where quick access to a blade is crucial.
How OTF knives work

Components of Double Action OTF Knife Blueprints

Blade Design and Materials

The blade is a critical component of any double action OTF knife, and its design and material selection can greatly impact its overall performance. When examining a blueprint, consider the following factors:

Blade shape

Common shapes include drop point, tanto, and spear point, each with its own strengths and weaknesses. The chosen blade shape should align with the intended use of the knife.

Blade material

High-quality steel, such as S30V, VG-10, or 154CM, is often used for crafting durable and sharp blades that can withstand frequent use and maintain their edge.

Blade length

The length of the blade will determine its cutting capability and legality in certain jurisdictions. Ensure that the chosen length adheres to local regulations and suits the intended purpose of the knife.

Blade coating

Some blueprints may include a blade coating for added corrosion resistance, enhanced aesthetics, or reduced glare. Common coatings include titanium nitride, DLC (diamond-like carbon), and Cerakote.

Handle Design and Materials

The handle of a double action OTF knife houses the intricate mechanisms that facilitate the deployment and retraction of the blade. When analyzing a blueprint, consider the following aspects of the handle:

Handle material

Popular materials include aluminum, G-10, and carbon fiber, each offering different levels of durability, weight, and grip. The selected material should provide a comfortable and secure grip while also complementing the overall design.

Handle shape and ergonomics

The shape and ergonomics of the handle play a significant role in the knife’s usability and comfort. The blueprint should outline a handle design that promotes a secure grip and minimizes hand fatigue during prolonged use.

Attachment points

Many double action OTF knives feature attachment points, such as lanyard holes or pocket clips, for convenient carrying options. Ensure that the blueprint includes the desired attachment points and their proper placement.

Opening and Closing Mechanisms

The opening and closing mechanisms are the defining features of double action OTF knives, and the blueprint should provide a clear and detailed representation of these components. Key elements to examine include:

Spring system

The type of spring system employed, such as a coil or leaf spring, will impact the knife’s deployment speed and force. Ensure that the blueprint specifies the appropriate spring system for the desired performance.

Button or lever

The button or lever used to activate the opening and closing mechanisms should be strategically placed for easy access and operation. Examine the blueprint to ensure that the button or lever design aligns with your preferences.

Locking mechanism

A reliable locking mechanism is crucial for the safe and secure use of a double action OTF knife. The blueprint should detail the type of locking mechanism used, such as a plunge lock or crossbolt, and its proper integration into the overall design.

Safety Features

Safety features are essential components of any double action OTF knife, as they help prevent accidental deployment and potential injuries. When reviewing a blueprint, consider the following safety features:

Safety switch

A safety switch can prevent unintentional activation of the opening mechanism, reducing the risk of accidental deployment. Ensure that the blueprint includes a safety switch and its optimal placement on the handle.

Blade stop

A blade stop can prevent the blade from overextending during deployment, protecting the knife’s internal components and the user. Verify that the blueprint specifies the appropriate blade stop design and placement.

OTF knife in hand

Reading and Interpreting Double Action OTF Knife Blueprints

Identifying Key Dimensions and Measurements

Blueprints use various dimensions and measurements to convey the exact specifications of each component. Familiarize yourself with these notations and ensure that they align with your desired knife specifications. Key dimensions to look for include:

  1. Blade length and width
  2. Handle length and width
  3. Overall length (when deployed and retracted)
  4. Spring system dimensions
  5. Button or lever size and placement

Understanding Symbols and Abbreviations

Blueprints often utilize symbols and abbreviations to represent specific components, materials, or manufacturing processes. Understanding these notations is essential for accurately interpreting and executing the design. Common symbols and abbreviations include:


Steel types, handle materials, and coating materials may be abbreviated or represented using industry-specific symbols.


Manufacturing tolerances indicate the allowable variance in dimensions and should be clearly marked on the blueprint. Familiarize yourself with these tolerances to ensure the final product meets the desired specifications.

Assembly notes

Blueprints may include assembly notes or instructions to clarify the proper assembly of components, such as the orientation of springs, washers, or other internal parts.

Tips for Blueprint Accuracy

  1. Double-check dimensions: Always verify the dimensions and measurements of each component to ensure they align with your desired specifications.
  2. Consult an expert: If you are unsure about any aspect of the blueprint, seek advice from an experienced knife-maker or engineer to avoid potential issues during the crafting process.
  3. Use appropriate tools: Utilize proper measuring tools, such as calipers and micrometers, to ensure accurate measurements during the crafting process.

Crafting Your Double Action OTF Knife

Tools and Equipment Needed

To successfully craft a double action OTF knife, you will need access to various tools and equipment. Some essential tools include:

  1. Metalworking tools: Files, grinders, and a bandsaw or hacksaw for shaping the blade and handle components.
  2. Drill and bits: A drill press and a variety of drill bits for creating holes and recesses in the handle and blade.
  3. Precision measuring tools: Calipers, micrometers, and rulers for accurate measurements during the crafting process.
  4. Assembly tools: Screwdrivers, pliers, and tweezers for assembling the knife’s internal components.
  5. Finishing tools: Sandpaper, polishing compounds, and buffing wheels for achieving a refined and professional finish.
OTF Knife blade

Safety Precautions during the Crafting Process

  1. Wear appropriate personal protective equipment (PPE), such as safety glasses, gloves, and hearing protection, while working with tools and equipment.
  2. Work in a well-ventilated area to minimize exposure to dust, fumes, and other potential hazards.
  3. Exercise caution when handling sharp blades and tools to prevent injury.
  4. Follow proper procedures for the safe operation and maintenance of tools and equipment.

Step-by-step Process for Building a Double Action OTF Knife

Preparing materials

Begin by sourcing the necessary materials, such as blade steel, handle materials, and internal components. Consult the blueprint to ensure you have the correct materials for each part.

Cutting and shaping the blade

Using the blueprint as a guide, cut and shape the blade to the specified dimensions. Grind the bevels and apply the desired edge geometry.

Creating the handle and internal mechanisms

Cut and shape the handle material according to the blueprint. Drill any necessary holes or recesses for the internal components, button or lever, and attachment points.

Assembling the knife

Carefully assemble the internal components, including the spring system, button or lever, and locking mechanism. Attach the blade to the handle and ensure it deploys and retracts smoothly.

Testing and troubleshooting

Test the deployment and retraction of the blade, as well as the locking mechanism, for proper function. Address any issues that may arise and fine-tune the knife as necessary.

Legal Considerations for Double Action OTF Knives

Federal and State Regulations

Laws surrounding the possession and use of double action OTF knives can vary greatly between jurisdictions. Familiarize yourself with federal, state, and local regulations before crafting or carrying a double action OTF knife.

Licensing and Permits

In some jurisdictions, a license or permit may be required to own, carry, or sell double action OTF knives. Ensure you obtain any necessary documentation to comply with local regulations.

Tips for Responsible Ownership and Usage

  1. Educate yourself on the legal restrictions in your area and adhere to them at all times.
  2. Use your double action OTF knife responsibly and for its intended purpose only.
  3. Store your knife securely and out of reach of children or unauthorized individuals.
  4. Familiarize yourself with proper knife handling techniques and safety precautions to minimize the risk of injury.

How Does a Double Action OTF Knife Work?

A double action OTF knife works by utilizing a spring-loaded mechanism that propels the blade out of the handle when the button or lever is engaged. The same button or lever also retracts the blade back into the handle when released. The key components of this mechanism include:

  1. Spring system: The spring system, which can be either a coil or leaf spring, provides the necessary force to deploy and retract the blade.
  2. Track or channel: The blade travels along a track or channel within the handle, ensuring smooth and consistent movement during deployment and retraction.
  3. Button or lever: The button or lever activates the spring system, controlling the movement of the blade.
  4. Locking mechanism: The locking mechanism secures the blade in either the deployed or retracted position, ensuring stability and safety during use.

Frequently Asked Questions

Can I use a double action OTF knife for self-defense?

While a double action OTF knife can be used for self-defense in certain situations, it is essential to understand the legal implications and potential risks involved. Always prioritize non-violent conflict resolution and ensure you are familiar with local laws and regulations regarding knife use in self-defense scenarios.

How do I maintain my double action OTF knife?

Regular maintenance is crucial for ensuring the longevity and optimal performance of your double action OTF knife. Some key maintenance steps include:

  • Cleaning the blade and handle regularly to remove dirt and debris.
  • Lubricating the internal mechanisms and pivot points to ensure smooth operation.
  • Sharpening the blade as needed to maintain a sharp edge.
  • Inspecting the knife for signs of wear or damage and addressing any issues promptly.

What materials are best for a double action OTF knife?

The ideal materials for a double action OTF knife depend on factors such as intended use, desired weight, and budget. Popular materials include:

  • Blade: High-quality steel, such as S30V, VG-10, or 154CM, for durability and edge retention.
  • Handle: Aluminum, G-10, or carbon fiber for a balance of strength, weight, and grip.


Creating a double action OTF knife is a rewarding endeavor that requires precision, attention to detail, and a thorough understanding of the knife’s intricate mechanisms. By following this comprehensive guide, you can successfully craft a high-quality double action OTF knife that not only functions flawlessly but also stands as a testament to your skill and dedication.

As you embark on this exciting journey, remember to adhere to all legal regulations, prioritize safety, and take pride in your craftsmanship. The result will be a remarkable tool that serves you well for years to come.

I'm Justin, co-founder of AllofKitchen and your knife and steel specialist. My extensive experience ensures accurate and hands-on advice on every topic. Turn to me for insights on selecting the best knife or maintaining your steel tools to perfection. Knives aren't just tools; they're an extension of the chef, and I'm here to guide you to the perfect fit.

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