Intro to Millwright Practice Exam

Which measurement system is not commonly associated with wrenches?

1. Metric (SI)

2. Decimal

3. English (SAE)

4. Imperial

The correct answer is: Decimal

The measurement system that is not commonly associated with wrenches is the decimal system. Wrenches are typically designed and calibrated using unit systems that directly correspond to the types of fasteners they are meant to engage. The metric system (SI) and the English system (SAE) are the two primary systems used in this context. In the metric system, wrenches measure sizes in millimeters, reflecting the dimensions of metric fasteners. For the English system, wrenches are often measured in inches, which aligns with the sizes of standard fasteners in the United States. The Imperial system, while often used interchangeably with the English system, also relates closely to inch measurements and is familiar to many users in various contexts. The decimal system, however, does not provide the specificity of measurements that wrenches need to engage specific fastener sizes, as it does not inherently define the units of measurement for nuts and bolts. Instead, the decimal system is more generalized and typically used for different applications that require numerical values without the strict context of fastening hardware. Therefore, it is not commonly associated with wrenches, which rely on definite and standardized units for effective use in mechanical applications.