The Importance of Geometric Dimensioning and Tolerancing in Aerospace
By Space Coast Daily // April 19, 2022
You cannot deny the communication importance in manufacturing. GD&T dimensioning helps the manufacturers, engineers, etc. to communicate in the same language. It describes how the parts fit together to make assemblies. The fitting of parts, their movement, and wear depend on the dimensioning and tolerancing.
Parts made without following the standards of GD&T are subjected to wear and fail over a short period. The dimensions and tolerance between the parts allow them to slide over each other, move, rotate, and function with the least friction and minimum material loss.
Accuracy of Manufactured Parts
In aerospace, injection moulding has been used to make the parts and geometries. Therefore, there is quite closer and tighter tolerance between the parts. Although the accuracy of the manufactured component in aerospace is increased by using tight tolerances there are more chances of defects and dimensional inaccuracy in the manufactured parts.
The parts that require tight tolerances need to be manufactured with high accuracy otherwise components may not fit together and go wasted. For this reason, in the aerospace industry, we need to put a lot of attention to the ASME standard of GD&T. GD&T provides us with the exact dimensions and tolerance of all the parts in the assembly and as a result, we get an accurate and precise component. This helps to save money and increase the life of the equipment.
Understanding of Technical Drawing
As, ASME standard gives a complete nomenclature that includes symbols, dimensions, metering system, etc. Therefore, the communication of drawing becomes universal. The engineers, manufacturers, and technicians can read the same drawing and GD&T Symbols due to GD&T standards. The conversion of drawing, change of symbols, or language is not required which has made the technical drawing reading much easier.
Improved Quality and Reliability
Using GD&T dimensioning, inspection time decreased, communication of drawing becomes easier, the rejection rate of components decreased, and the reliability of manufactured components increased.
As the components in aerospace like propeller blades, engine parts, etc. are highly expensive. Also, these components have tight tolerances. If the components are manufactured without following the GD&T standards or small negligence happens, the components may get wear and tear while in use or even it does not fit.
That results in huge losses of money, material, and manufacturing cost. That is why GD&T is given much importance in the aerospace industry to save costs and improve the life of equipment by using correct dimensioning and tolerances.
Repair and Dis-assembly Requirements
Usually, components in aerospace need to be disassembled for repair and cleaning purposes. When the components are disassembled and need to be assembled again, dimensioning, tolerancing, and fitting of components together is again an issue. But by using GD&T dimensioning standards, the components can fit together again and there is no need to get help from the manufacturer. This is a great advantage of a standard GD&T in aerospace.
GD&T increases the flexibility in manufacturing for example it tells how much variation in diameter, length, depth, etc. is allowed for a particular assembly. Similarly, it tells the variation of dimensions and tolerance while still allowing the proper assembly of parts. It increases the flexibility in manufacturing and as a result, the manufacturing process becomes reliable, easy and accurate.