THREAD SETTING PLUG
A thread setting plug is used in conjunction with ring gages as part of the inspection process for threaded parts. While ring gages are used to inspect the external threads of cylindrical parts, thread setting plugs are used to inspect the internal threads, ensuring that both the internal and external threads of a part meet the specified requirements.
Here’s how a thread setting plug works in use with ring gages:
- Verification of Thread Fit: Thread setting plugs are designed to simulate the mating external threads of the part being inspected. When the thread setting plug is inserted into the thread ring gage, it should engage smoothly and fit snugly, indicating that the internal threads are properly formed and within the specified tolerance limits.
- Dimensional Inspection: Thread setting plugs are precision instruments manufactured to exact specifications. By using a thread setting plug along with a ring gage, manufacturers can perform comprehensive dimensional inspections of both internal and external threads to ensure that they meet the specified dimensional requirements, including pitch diameter, thread depth, and thread form.
- Calibration: Thread setting plugs are used for the calibration and verification of ring gages. By inserting the thread setting plug into the ring gage, manufacturers can ensure that the ring gage is accurately sized and calibrated to the specified thread dimensions. This helps maintain the accuracy and reliability of the inspection equipment used in the production process.
- Quality Control: The use of thread setting plugs in conjunction with ring gages is essential for quality control purposes. By inspecting both internal and external threads of threaded parts, manufacturers can identify any deviations from the specified thread parameters and take corrective actions to ensure product quality and reliability.
Cam-Tech Industries uses HIGH LO setting plugs that take the guess work out of setting adjustable ring gages. HIGH LO master setting plug gages are designed to precisely size and check minimum and maximum tolerance of adjustable and solid type ring gages. They’re also ideal for checking flank wear and to determine excessive bell mouthing.
For Highly Accurate Adjustable Ring Gage Setting:
HIGH LO setting plugs take the guesswork out of setting high and low tolerances of adjustable thread ring gages. These unique setting plugs are designed with two different thread pitch diameters. The front section is the low tolerance limit, and the back section is the high tolerance limit. By adjusting the ring gage so it will thread onto the front section without threading onto the back section, a precise setting is achieved.
Worn Flank Checks:
The back section, or the high limit end of each HIGH LO setting plug has the outside diameter of the thread truncated in accordance with H-28 Screw Thread Standards for Federal Service, latest revision. It automatically furnishes a check on worn flanks similar to, but more exacting than, standard truncated setting plugs.
Angle Checks:
In addition, HIGH LO setting plugs can provide a precise angle check on ring gages because, of the high limit pitch diameter, and the low limit outside diameter on the back section of the setting plug. Any worn flanks or angles will be indicated when the ring fits snugly on low pitch diameter section and still enters the high pitch diameter section.
Bell Mouthing Inspection:
The amount of excessive ring gage bell mouthing can be determined if the ring gage accept the high section of the setting plug, by more than two turns. If the ring gage accepts less than two turns, the ring gage is within tolerance.
In Summary:
Thread setting plugs complement the use of ring gages by providing a means to inspect the internal threads of threaded parts. Together, they form a comprehensive inspection system for verifying the dimensional accuracy and quality of threaded components according to industry standards such as ASME B1.1 or ASME B1.2.