Q1: Which of the following are made out of the carbon steel having carbon content of 0.9 to 1% ?

ANS:A - Small punches, broaches reamers and springs.

The correct option among the ones provided is: Mandrels, twist drills, small lathe tools, and razors. Carbon steel with a carbon content of 0.9% to 1% is typically classified as high carbon steel. High carbon steel is known for its hardness, strength, and wear resistance, making it suitable for applications requiring these properties. Mandrels, twist drills, small lathe tools, and razors are tools that require hardness and wear resistance, making high carbon steel with a carbon content in the specified range suitable for their construction. The other options do not typically require high carbon steel with a carbon content of 0.9% to 1%:

• Small punches, broaches, reamers, and springs may be made from medium carbon or alloy steels, which provide a balance of strength, toughness, and wear resistance.
• Cutlery, screws, rivets, and files may be made from low to medium carbon steels, which offer good formability, machinability, and corrosion resistance.
• Forgings like can shafts, structural steel plates, threading dies, and drawing dies may be made from various grades of carbon steel, depending on the specific requirements of the application.