Month: October 2023

Do you know what geometric tolerance symbols are? When it comes to ensuring product quality, these are the most important elements of a technical drawing. Any dimension outside the tolerance indicates a nonconformity. You must be able to interpret measurement results based on the tolerances of the technical drawing. What are geometric tolerance symbols? When designing parts, the engineer creates a technical drawing and includes key dimensions onto it. These are called nominal dimensions. It is impossible to produce a series of products according to nominal dimensions only. Therefore, deviations from the dimension are used, which are referred to as dimensional tolerances. These may apply to various elements and areas of the product. Therefore, geometric tolerance symbols are defined. What are they? These are all “figures” that appear next to a numerical value and refer to a specific product characteristic. In practice, there are several symbols used that mean the same thing all over the world. Regardless of whether the drawing was designed in Japan or in the USA. Understanding and remembering what each symbol means will help you to interpret measurement results. Geometric tolerance symbols are divided into four categories: Geometric tolerance symbols – definitions and examples Knowing these […]

One of the main methods of joining metal elements is the welding process. Welding is a special process and requires precise determination of process parameters. One important aspect is determining the requirements for the weld. The marking of the weld in the drawing and its names are strictly defined. It is accepted in the industry that welds are divided into three categories: butt welds, fillet welds and others. There are also a number of subcategories of welds. Types and symbols of weld marking in the drawing Method of marking the weld in the drawing Welds are marked in a specific way in the drawing, their characteristics are defined by 8 points. It is common to see less information in a drawing (4-5 points) because it is sufficient for description. A detailed description of the points with an illustration below Method of marking weld quality control methods in the drawing When special non-destructive inspection of a weld is required, it is necessary to include this information in the weld description on the drawing. The test method is then specified in point 8 by a two-letter description. Below is a “decipher” of possible descriptions: • VT – visual examination of the weld […]

Do you know which tool to choose for a given dimension? Or do you measure with what is at hand? Maybe you always choose a digital caliper because it’s easiest? A well-selected measuring tool for a given specification will avoid potential quality complaints about the product. If you don’t know what criteria to follow, you’re probably doing it wrong. Selection of measuring instruments – key rules First, a few crucial general rules with a simple, but very interesting, example to folow. This will Pinpoint of how a poorly selected tool introduces a huge risk of making a wrong decision regarding compliance with the specification. What to do when we receive an element to be measured along with a technical drawing? What should you consider when selecting a measuring tool? That doesn’t mean you measured wrong…I assume you did everything correctly. The measurement result is so-called observed, it is subject to measurement uncertainty. Uncertainty of measurement Measurement uncertainty is a symmetrical interval around the measurement result, which contains the actual value with a certain probability. The sources of uncertainty are different and depend on a given measurement procedure, they may result from: the tool, the measured object, environmental conditions, the person […]