Millwright Level 1 Practice Exam

What material are cap screws primarily made of?

1. Stainless steel

2. High tensile steel

3. Aluminum

4. Plastic

The correct answer is: High tensile steel

Cap screws are primarily made of high tensile steel because this material provides the strength and durability necessary for fastening applications in various mechanical contexts. High tensile steel is designed to withstand significant loads and stresses, making it an ideal choice for cap screws, which need to maintain strong connections in machinery and structures. The use of high tensile steel allows for the production of screws that can endure high levels of tension without deforming, ensuring reliable functionality in demanding environments. While other materials such as stainless steel may also be used in some applications for their corrosion resistance, they do not typically achieve the same level of tensile strength as high tensile steel. Aluminum, on the other hand, is lighter and more prone to wear under heavy loads, making it less commonly employed for cap screws in heavy-duty applications. Plastic is generally unsuitable for applications requiring high strength and load-bearing capacity, as it cannot accommodate the same stress levels as metal-based screws.