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Posted by Joe Cimoch [68.116.181.98] on Tuesday, July 13, 2010 at 08:43:21 :
In Reply to: OT/ drill bits. Good stuff. posted by The Dodge Boys [207.172.238.54] on Monday, July 12, 2010 at 21:00:13 :
Its getting harder and harder to find anything manufactured in the USA. What's a good price for the bits? eBay has a 6 pack of 1/4" bits for $28.89 (cost + shipping). So a little less than $5.00 for a 1/4" bit. In comparison, I bought a long 1/16" bit yesterday for about $3.00, that broke on the 2nd use, probably too thin for that length drill anyway.
Q: Hello I have never heard of this type of material,is this comparable to cobalt coated?or full cobalt.
A: I like them much better than cobalt, I am a mechanic/fabricator by trade and I use them all the time. These drills start drilling on contact, no pilot hole necessary. Here is a little more info on the difference between the magnum high moly and the colbalt drills:
Magnum™ Vs. Cobalt The Magnum™ drills will substantially outperform cobalt drills in work hardening stainless steel applications. This performance advantage is the result of construction differences between the two types of drills. Cobalt drills, manufactured to Type J NAS 907 specs, have a very thick web. This web is necessary to limit breakage of the brittle cobalt steel. Magnum drills are made of special hi-moly tool steel, which is much tougher than cobalt steel. The web on a Magnum drill can be thinned considerably due to the toughness of the steel. (See Illustration A) A Magnum drill with its thin web will penetrate the work hardening stainless fast enough to continually cut beneath the chip which is hardening from deformation. This means the drill is cutting softer steel. The cobalt drill, with its thick web, cannot be fed at a fast enough rate to cut beneath the area which is hardening. As a result the cobalt drill is continually drilling into hardened steel.
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