What Affects the Strength of Steel?

Steel strength depends on (1) the steel alloying and (2) how heat treatment arranges everything within the steel (called 'microstructure'). To demonstrate this, different types of steel bolts (different alloying) are heat treated in different ways and their strengths measured. Its a great introduction to the fundamentals of steel alloying, heat treatment and microstructure. This content is largely based on my book - Steel Isn't Hard (to learn). This was my first full-length video. Please be kind about the audio. #Metallurgy #Steel #Engineering