| Stub ACME Screw Threads
American National Standard Stub Acme Threads are defined in ASME/ANSI B1.8 and are for a typical applications where due to mechanical or metallurgical considerations, a coarse-pitch thread of shallow depth (thin wall) is necessary. The fit of Stub Acme threads corresponds to the Class 2G General Purpose Acme Thread found in ASME/ANSI B1.5. For a fit having minimal backlash, the tolerances and allowances for classes 3G or 4G General Purpose Acme Threads may be used. |
| The Stub ACME screw thread form can be applied to either Genrral or Centrializing ACME screw threads. |
| The Major and Minor Diameter allowances for Stub Acme threads are the same as those given for General Purpose or Centrializing Acme screw threads. Pitch Diameter allowances for Stub Acme threads are the same as for Class 2G General Purpose or Centrializing Acme Screw Threads. Stub Acme Threads have a preferred series of diameters and pitches which happens to be the same as General Purpose or Centrializing Acme Screw Threads. |
| The proper method of designation for Standard Stub Acme threads is illustrated in the following examples: 0.500″-20 Stub Acme-2G … indicates that the thread has a ½” major diameter, 20 threads per inch, class 2G, right hand, single thread, Standard Stub Acme thread. This Designation stays the same with Left Handed Threads except you add LH behind the description, for example: 0.500″-20 Stub Acme-2G LH. |
| Complicating the world of ACME further, the Standard Stub Acme does not always provide an accepted thread for all applications. Basic data for two other frequently used forms have been tabulated. These are designated MODIFIED Forms 1 and 2. You are strongly urged to ALWAYS use the Standard Stub Acme form in preference to the Modified form where it is realistic. Using the modified form does not eliminate the requirement for identifying the class-of-fit. |
| Modified Form 1, (M1) – The pitch and minor diameters will be smaller than similar values for the standard form. |
| Modified Form2, (M2) – The pitch and minor diameters will be larger than values for the standard form. |
| Thread designation is the same as the Standard Stub Acme except that you add the M1 or M2 after the Class or hand in case of a LH thread (i.e. 0.500″-20 Stub Acme-2G M1 or 0.500″-20 Stub Acme-2G LH M1) |
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Disclaimer:
This data is provided for general information only. The intention is to provide accurate information,regardless,errors may exist in the supplied information. If accuracy is critical, base your final decisions on the data provided in the root document: ANSI/ASME B1.8; If you any request or questions please contact ： sales@fyougauges.com
For more information click the links below:
General Purpose ACME Screw Thread Data per ANSI/ASME B1.5
DESIGN PROFILE FOR EXTERNAL AND INTERNAL GENERAL PURPOSE ACME THREAD