Pressure Tight Thread Joints ISO 7-1

ISO 7-1 tapered threads are equivalent to DIN 2999, BS 21 (BS EN 10226-1), JIS B0203. Characteristics of ISO 7-1 tapered threads:

• tapered thread 1^o47'
• truncation of roots and crests are rounded
• 55^o thread angle
• pitch is measured in threads per inch

Note!

There is a distinction between

• jointing threads - which are sealing piping threads for connections to ISO 7-1 and/or EN 10226-1
• fastening threads - which are not sealing parallel threads for connections to EN ISO 228-1

The outside diameter of a pipe or fitting must be measured and compared to a table for size identification. A 3/4" ISO 7-1 pipe thread has an outside diameter - OD - of 1.060 inches. Each thread size has a defined number of threads per inch - TPI, or pitch. The 3/4" NPT pipe thread has 14 threads per inch. Both the TPI and OD of the thread are required for positive identification of thread size because more than one size have the same TPI.

ISO 7-1 threads may look similar to NPT threads. However, ISO and NPT threads should not be mixed. ISO threads have 55^o taper angle versus 60^o for NPT. The NPT root and crest configurations are also different from ISO. For ISO threads pitch is usually measured in millimeters ( may be expressed in Inch). The pitch are different.

Length of Thread to make Tight Joint

Search the Engineering ToolBox

Engineering ToolBox - SketchUp Extension - Online 3D modeling!

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your SketchUp model with the Engineering ToolBox - SketchUp Extension/Plugin - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp from the Sketchup Extension Warehouse!