If the balls are steel they are then heat treated.
The presence of these minerals indicates the samples were not heat treated.
If better properties are required then it may be heat treated or cold worked.
Many Model 33 parts were not heat treated and hardened.
With both these methods, after shaping, the steel must be heat treated.
Since 1986 all blood has been heat treated and there have been no cases since then.
The glass was only replaced in 1991 with sealed heat treated solar reflective system.
They are then typically heat treated and cut to length.
The master hub is then heat treated to make it hard.
The barrel was then heat treated several times in facilities such as a large vertical furnace.