Detailed Explanation of Plug Gages, Their Functioning and Uses

Plug Gages

Explained in simple terms, a plug gage is used to check the size of the drilled holes. This is extremely important in applications where the pre decided size of the drilled hole must be achieved. This can be done in two ways. The first way is to check the size of the drilled hole during the manufacturing process, i.e. On-line or Real Time Inspection. Second method is to check the sizes after the gage is manufactured. These gages can be straight or tapers, plain or threaded, depending on the customer's needs.

Here, the concept should be noted that a gage is not a plug but a tool for measuring whether the given screw or plug will fit into the hole.

Working of Gages

These gages are inserted into the drilled hole. If the gage slips in the hole for the given size then the hole is said to be correctly manufactured. There are different types of gages available for measuring different types of small parts such as screws, nuts.

The Go and No GO Concept

There is a concept called ‘GO' and ‘No GO'. As the name suggests a go measure tells us how much the part to be fitted in the hole goes ‘inside' of the hole. While a no go measure tells us how much part of it should not go ‘inside' the hole. Hence if a gage ‘goes in' exactly as per the ‘GO' measurement and ‘does not GO' as much as told in the ‘NO GO' measurement, it is said to be manufactured correctly.

Manufacturing Plug Gages

Since Carbide balls give maximum wear resistance and hardness, gages are made of Tungsten Carbide. They give the required tolerance levels in the risky (prone to hazards etc.) environment of factories.

Uses

Types of these gages are - Taperlock, Cylindrical Taper, Trilock, and Reversible gage. These gages return a state whether the drilled hole is acceptable or not acceptable and hence one does not have to measure the actual sizes etc. of any of the parts. Hence, their use can be found mostly in production industry where very little skills are little interpretation is needed. Plug gages are used in design and, mechanical engineering and water flow engineering etc..

Tolerance Levels

There are various tolerance levels, four important ones among them are X, Z, XX and ZZ. More than any other property, Gages are determined by their tolerance levels.

Selecting Suitable Gage for Your Need

There are many factors to consider before selecting plug gages for your needs. Few among them are mentioned here – Maximum Tensile and Compressive and transverse rupture Strength of the carbide balls since they have wear parts. The maximum temperature should also be considered in which the gage can work.

About the Author

Machining Technologies of known worldwide for its a high-tech, state-of-the-art manufacturing facility. We have progressively expanded our manufacturing and worldwide product line to include wear parts components, tungsten carbide balls, stainless steel balls, carbide blanks, plastic balls, tungsten carbide, and plug gages.