| | |   M42 molybdenum cobalt steel bit. A typical fairly large milling machine bit called an end mill.  It is made of M42 molybdenum-cobalt steel allow, often called cobalt steel because even though it has more molybdenum than cobalt in it, it is an alloy distinguished by its cobalt content being higher than that in most others steels.
 Source: eBay seller aztool-jerry
 Contributor: Theodore Gray
 Acquired: 11 March, 2009
 Text Updated: 12 March, 2009
 Price: $15
 Size: 4"
 Composition: FeMoCo
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