Specification for pipe threads for tubes and fittings where pressure-tight joints are not made on the threads metric dimensions. Convert to threads per inch by dividing into 25. An appropriate thread sealant can be used, if necessary, to ensure pressure-tight joints. Parallel threads also called straight threads and taper threads. The gauging system defined in is technically equivalent to the gauging system defined in. See chart on front side of this sheet. These threads are of Whitworth form and are used when pressure tight joints are made on the screw threads.
Using these components pressure tight joints are made my using soft annulus seals between a backnut and a connector face. If pitch is not called out, the coarse thread is assumed. Components having pipe threads produced to the dimensions and tolerances given in this standard can be assembled to give safe and effective pressure tight joints providing proper assembly techniques are used. Both female Rp - internal cylindrical threads - and Rc - internal taper threads - are used in combination with male R - external threads - to make sealed joints. Pitch is the distance between adjacent thread crests.
Note 4: gives details of recommended gauging systems for the verification of thread dimensions and thread form. Please read for more information. Add the Engineering ToolBox extension to your SketchUp from the Sketchup Extension Warehouse! Major Diameter: The maximum diameter of a thread which is diameter of the crest of a male thread or root of a female thread. Pitch is the distance, in mm, between adjacent threads. Pipe threads where pressure-tight joints are made on the threads -- Part 2: Verification by means of limit gauges. For pipe threads where pressure-tight joints are not made on the threads.
Wrenching Allowance: Useful thread length which is provided to accommodate for wrenching beyond the position of handtight engagement. Thread which is not full formed at the root. Example external taper thread designation. Taper threads seal on the threads themselves. It was in 1841 that Sir Joseph Whitworth created a threading system, the Whitworth thread, based on a 55 degree thread angle with rounded roots and crests. The techniques used to assemble threaded joints are dependent on a number of factors including the internal thread parallel or taper , the quality of the mating threads, the materials o the components being connected, the thread sealant or joining compound used and the assembly torque.
Parallel external pipe threads are not suitable as joining threads. Sometimes other sizes are available. For the 7-bit coded character set, see. In general engineering use, calculations can be done by selecting a standard metric thread size from the list which contains metric thread sizes in the diameter range from 1. The common requirements for the taper external pipe thread are in Part 1 and in ; so as to present the complete thread joining system in each part.
There are two calculation options available, general engineering use or custom use. On many threads a good drill size for tapping can be figured by subtracting pitch from major outside diameter. There is a coarse and a fine thread series. The taper is 1 to 16, measured on the diameter. Note: These thread sizes are not used as port threads in components.
It includes the wrenching allowance. They seal with a metric O-ring. These threads are taper external, parallel internal or taper internal and are intended for use with pipes suitable for threading and for valves, fittings or other pipeline equipment interconnected by threaded joints. Useful thread: All thread except washout thread. Click arrows to page adverts Pipe Threads. The taper is 1 to 16, meaning that for each 16 units of measurement increase in the distance from the end, the diameter increases by 1 unit of measurement. Fitting Allowance: The external thread beyond the gauge plane which is required to provide an assembly with an internal thread at the upper limit of tolerance.
On external threads the distance from the gauge plane to the small end of the thread. Male G-threads parallel can only be screwed into female G-threads. Pitch the distance between threads is expressed as the number of threads per 25. Straight thread ports are shown on the back side of this sheet. © 1990 by Womack Machine Supply Co. After coating, the actual thread profile shall not at any point transgress the maximum material limits for positions h or H.