inchschroefdraden

Inchschroefdraden, also known as unified screw threads, are a system of screw threads widely used in the United States and Canada. Unlike the metric system, which uses millimeters as its unit of measurement, inch threads are based on the inch. The most common types of inch screw threads are the Unified National Coarse (UNC) and Unified National Fine (UNF) series.

UNC threads have a coarser pitch, meaning there are fewer threads per inch. This makes them stronger and less prone to damage during handling, making them suitable for general-purpose applications and materials like softer metals and plastics. UNF threads, on the other hand, have a finer pitch, with more threads per inch. This finer pitch allows for more precise adjustment and a stronger hold in harder materials, making them ideal for applications requiring high accuracy or vibration resistance.

The designation of an inch screw thread typically includes a number representing the major diameter (for sizes 1/4 inch and smaller) or the diameter in inches (for sizes larger than 1/4 inch), followed by the thread per inch (TPI) value, and finally the thread series (UNC or UNF). For example, a 1/4-20 UNC thread has a major diameter of 1/4 inch and 20 threads per inch with a coarse pitch. A 1/4-28 UNF thread has the same major diameter but 28 threads per inch with a fine pitch.

Another important aspect of inch threads is the thread angle, which is typically 60 degrees for both UNC and UNF. This standard angle ensures interchangeability and compatibility between fasteners. While inch threads are still prevalent, the metric system has gained significant traction globally due to its simplicity and widespread adoption in international standards.