Protect your photos, music and documents and access to them anywhere with Mosey by e m C the most trusted name and cloud backup and now save ten percent with promo code. Brain Stuff at mosey dot com. Get started today at m o z y dot com. Welcome to brain Stuff from how Stuff works dot com where smart Happens. Hi Marshall Brain with today's question, what does case harden mean? When it's stamped on a piece of metal? Steel is
an amazing substance. By mixing in different elements and heating and cooling it in different ways, you can create surprisingly different properties. Some steels are easily bent, while others are so brittle that they shatter some rust, and others don't. The huge variety of steels means that they work in many different situations. Everything from a surgical scalpel to a skyscraper's massive metal frame can be made of steel. The idea behind case hardening is to have two different types
of steel in this same piece. During manufacturing, what you would like is a relatively soft steel that's easy to bend into machine for a lock shank. However, a soft steel is not good because it's easy to cut with a metal saw, so after the piece is formed, you harden it to make it very difficult to cut. Case hardened steel is usually formed by diffusing carbon or nitrogen into the outer layer of the steel at very high temperature. The carbon combines with the steel to make it nearly
glass like and its hardness. The core of the metal stays soft. This gives you a piece of metal that cannot be cut with a saw, but also will not shatter. Do you have any ideas or suggestions for this podcast? If so, please send me an email at podcast at how stuff works dot com. For more on this and thousands of other topics, go to how stuff works dot com. Your photos, music and documents are irreplaceable. Protect them with Mosey by e m C, the most trusted name and
cloud back up. Back up your files today and save ten percent with promo code brain stuff at mosey dot com m o z y dot com