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what is the go no-go gauge

In mechanical manufacturing, some products have high precision or cannot be measured in certain areas, but we must evaluate whether the processing requirements are met. Based on this, engineers have developed GO NO-go gauges to inspect certain features, such as holes, outer diameters,geometric tolerance, threads, etc. This not only helps us intuitively evaluate whether the processing meets the requirements, but also greatly improves the efficiency of inspection. The main method is to use comparison.if the products are small batches, we can develop separate gauges to ensure that the delivered products meet the requirements.

GO gauge and NO-GO gauge are one type of measuring tool, usually used in pairs, mainly used to check whether the dimensions of the workpiece are within the specified tolerance range, widely used in mechanical manufacturing, processing and other fields. Here is a detailed introduction for you:

Basic concepts

go gage

Its size is designed as the maximum limit size (the minimum limit size for holes and the maximum limit size for shafts). During inspection, the function of the gauge is to determine whether the actual size of the tested workpiece exceeds the minimum allowable size. If the gauge can pass the tested workpiece smoothly, it means that the workpiece is qualified in this dimension direction, because its actual size is greater than or equal to the minimum limit size.

no-go gauge

Its size is designed as the minimum limit size (maximum limit size for holes, minimum limit size for shafts). NO-GO gauge is used to check whether the actual size of the tested workpiece exceeds the maximum allowable size. If the gauge cannot pass through the tested workpiece, it indicates that the workpiece is qualified in this dimension direction, that is, its actual size is less than or equal to the maximum limit size.

Working principle

The working principle of the GO gauge and NO-GO gauge is based on the principle of determining the limit size. By measuring the contact between the through gauge and the measured workpiece, it is possible to quickly and easily determine whether the workpiece size is qualified, without the need for precise measurement of specific size values, thereby improving inspection efficiency.

Common types

plug gauge

Mainly used for measuring internal dimensions such as aperture or slot width. For example, when checking the aperture, if the gauge can be inserted into the hole but the stopper cannot, it indicates that the aperture size is qualified.

ring gauge

Commonly used for measuring external dimensions such as shaft diameter. If the shaft can smoothly pass through the through GO gauge of the ring gauge but cannot pass through the NO-GO gauge, it indicates that the shaft diameter dimension is within the tolerance range.

Thread GO NO-GO gauge

Specially used to verify the dimensional accuracy of threads, including parameters such as major diameter, minor diameter, pitch, and pitch. If the GO gauge can be smoothly screwed into the thread and the NO-GO gauge cannot be screwed in, it can be judged that the thread is qualified.

There are various types of gauges, including straight pipe threads with two ends and one end, NPT taper pipe threads that merge into one end, and more precise NPTF that requires three inspection ends,

Usage and precautions

Usage

When using, first make contact between the GO gauge and the workpiece being tested, so that it passes through the tested part as much as possible; If the general rules pass smoothly, then use the NO-GO rules for inspection to see if the NO-GO rules can pass. If the pass GO gauge can pass and the NO-GO gauge cannot pass, the workpiece size is qualified; If the GO gauge cannot pass or theNO-GO gauge can pass, the workpiece size is not qualified.

precautions

Before use, check the surfaces of the GO gauge and NO-GO gauge for any damage, deformation, or other defects to ensure the accuracy of the measuring tool. Handle with care during operation to avoid collision; During inspection, theGO gauge and NO-GO gauge should be kept coaxial with the axis of the tested workpiece, avoiding tilting or forced passage, so as not to affect the accuracy of the inspection results and damage the measuring tools. At the same time, it is necessary to regularly calibrate and maintain the GO and NO-GO gauges to ensure their measurement accuracy.

GO  and NO-GO gauges are indispensable measuring tools in mechanical processing and quality control, which are of great significance for ensuring product quality and improving production efficiency