Steel gage blocks or ceramic gage blocks – which to choose? Before we get into that, let’s take a quick look at gage blocks themselves. First of all, what are they?
What Are Gage Blocks?
In order to find accurate lengths, some people use, as their precision measurement tool, gage blocks. Originally, they were created to lessen the number of separate required gages needed to make industrial product measurements. By combining them in different formulations, a set of gages could be used to complete measurements of a wide range. Today we have gage block sets. Each block measures and exact length and is made precisely. Any number of precision measurements can now be calculated by combining these blocks (or wringing, or sticking them together). Ordinarily, the goal is to use as few blocks as possible to help eliminate the possibility of measurement error.
Gage Blocks and Grades
Before we discuss steel versus ceramic, let’s talk about grades. When you shop for meats, chances are, you’d like to look for “grade a. It’s better meat.
When a higher grade is attached to a gage block, it means that the blocks have a higher tolerance. They are more accurate and precise. As the tolerance degree is tighter, the higher the grade. A broad way of looking at it is that tolerance is the variation limit in the properties allowed by a specific material.
However, even within a particular grade, the tolerance can vary. This is largely dependent upon whether the block is made of metal or ceramic. And now we get down to it.
Steel Versus Ceramic
You probably already assumed that there are advantages and disadvantages to each material. Let us first take a look at ceramic:
- Ceramic blocks are popular, albeit less common than steel. It has an almost zero thermal expansion coefficient, which is a huge plus. So that no matter what the surrounding temperature, or how it changes, minimal alteration in size will be experienced by ceramic gage blocks. A zero phase shift is also a characteristic of ceramic gage blocks. As you can imagine, these are highly desirable features as they lend themselves to more exact, precise, and dependable measurements. On the other hand, they don’t stand up quite as well as the steel version. If they are hit or dropped, they can crack or chip. They don’t scratch easily, however, and they will not corrode over time. And that takes us to steel.
- Gage blocks made from steel are the most common. Why is steel preferred by some? During the lapping process, it holds up well and withstands normal usage. In many cases, it also matches the material from which the industrial products it is measuring is made. (Not to mention, it’s made from the same material that many industrial machines are made from.) This comes into play when discussing thermal expansion. Like materials mean that there may not be the need for the use of a thermometer when taking accurate measurements. Unfortunately, these do corrode after time. So, while inexpensive to replace, you may replace them more often, depending on your surroundings and how you care for them.
We carry blocks and block sets by Fowler, Starrett, Mitutoyo, and more in varying styles and types. When it comes to the gaging and metrology industry, in fact, numerous businesses depend on Willrich Precision Instruments for all their measurement needs. Browse through our gaging and metrology catalogs today or speak with a customer service representative to find out how we can help you make the most accurate, dependable measurements possible.