Screw pitch gauges, fine cutted threads UNC, UNF, SAE

Screw pitch gauges – Vogel 4710 are tools used to measure the pitch or lead of a screw thread. The screw pitch gauges consists of a series of thin metal leaves, each marked with a specific thread pitch, which is the distance between adjacent threads. By matching the leaves to the threads of a screw, users can determine the thread pitch accurately. This tool is essential in fields like mechanical engineering and machining to ensure compatibility of threaded parts and to identify the thread specifications of unknown screws. This tool is one of the indispensable test & measuring tools for technicians.

Each designed for precise measurement of thread pitches in both metric (mm) and imperial (inches, t.p.i. – threads per inch) units. These gauges are used for internal and external measurements of threads, particularly for finely cut threads.

Each product number (Art.-No.) corresponds to a specific number of blades (Blades) and a measurement range (Range). These models are designed to measure various types of threads, from metric (metr.) to Whitworth (whitw.) and American standard threads (SAE, UNC, UNF), catering to diverse needs in the mechanical engineering and machine manufacturing industries.

What is meaning of tpi, UNC, SAE, UNF and Withworth?

• TPI: TPI stands for “Threads Per Inch.” It is a measure of the number of thread peaks per inch length along the fastener. TPI is a crucial parameter in thread specification, especially in imperial or U.S. customary units, helping to determine the thread coarseness or fineness.
• UNC: UNC stands for “Unified National Coarse.” It is a type of threading used on bolts, nuts, and screws. UNC threads have a larger thread pitch (fewer threads per inch) compared to fine threads, making them more suitable for general assembly or where quick assembly or disassembly is desired.
• SAE: SAE stands for “Society of Automotive Engineers.” This term is often used to refer to a type of thread or fastening standard developed by the SAE. The SAE standard for threads is similar to the Unified Thread Standard (which includes UNC and UNF), and it is widely used in automotive and aeronautical engineering.
• UNF: UNF stands for “Unified National Fine.” It is another type of threading, part of the Unified Thread Standard. UNF has a finer thread pitch than UNC, meaning there are more threads per inch. This finer threading allows for greater control in tightening and is often used in applications where precision and strength are important.
• Whitworth: The Whitworth thread standard is one of the oldest and was the first to be standardized. Developed by Sir Joseph Whitworth in Britain in the 19th century, it was widely used in the UK and the Commonwealth. Whitworth threads are characterized by their specific profile angle (55 degrees), thread form, and pitch. The Whitworth standard differs significantly from the Unified Thread Standard (UNC and UNF).