Finish the following sentence with the best choice: How are slip gauges made?

Choices:
- Most of the slip gauges are produced from high grade steel, hardened and stabilized by heat treatment process to give a high degree of dimensional stability
- Most of the slip gauges are produced from high grade steel, hardened and stabilized by a laser treatment process to give a high degree of dimensional stability

Answer:
Most of the slip gauges are produced from high grade steel, hardened and stabilized by heat treatment process to give a high degree of dimensional stability