Selecting the most cost effective and appropriate types of thread makes your job reliable and easy. Identifying cotton thread, polyester thread and royan thread is therefore essential for proper splicing. Straight threads (also called parallel threads) and conical threads are the two main types of threads.

There are different types of threads found and some main types of threads are parallel threads including BSPP, UN/UNF and metric parallel. The second type of thread is tapered, including metric tapered, BSPT, and NPT/NPTF threads.

What Is Screw Thread?

We use a helical structure to convert between rotary and linear motion, called a thread or screw thread. Threads are essential features of a screwing machine and threaded fasteners.

We use a screw thread in various applications; it wraps around a cone or cylinder as a ridge. The thread is in the form of a helix. The pitch of a thread is the linear distance the screw can travel in one revolution, and the mechanical advantage of a thread depends on its pitch.

There are two common forms of threads: straight threads and tapered threads.

Straight threads have a parallel profile that remains the same diameter throughout the part.

Tapered threads taper with the thread profile and become smaller in diameter as the part moves down.

Geometric Parameters of the Thread

Understanding the geometric parameters of a thread is crucial for ensuring proper fit and function. Key parameters include:

• Thread Pitch: The distance between adjacent threads, measured in millimeters or threads per inch.
• Thread Diameter: The outer diameter of the thread.
• Thread Angle: The angle between the flanks of the thread, typically 60° for standard threads.
• Thread Depth: The distance from the crest to the root of the thread.
• Thread Form: The shape of the thread profile, such as triangular or square.

Different Types of Screw Threads

Screw threads come in various forms, each suited to different applications:

• Unified Thread Standard (UTS): Common in the U.S., with threads like UNC (coarse) and UNF (fine).
• Metric Threads: Used globally, with standard types such as M (metric coarse) and MF (metric fine).
• Pipe Threads: Includes NPT (National Pipe Tapered) and BSP (British Standard Pipe), used for fluid connections.
• Acme Threads: Known for their trapezoidal profile, used in machinery for power transmission.
• Square Threads: Used for high-load applications due to their efficient load distribution.

Important Tips to Choose the Right Screw Thread

• Application Requirements: Consider the load, environment, and movement needs.
• Thread Compatibility: Ensure the thread type matches with corresponding nuts or components.
• Material Considerations: Choose threads and materials based on strength and corrosion resistance.
• Precision Needs: For high-precision applications, select threads with tighter tolerances.

Sourcing Simplified – Start Your Next Project With PROTO MFG

For high-quality threading and machining solutions, partner with PROTO MFG. They offer expertise in various thread types and geometric parameters to meet your project requirements. Visit www.mfgproto.com to learn more and get started on your next project with confidence.