 John GaltForward, MarchPremium
join:2004-09-30
Happy Camp
kudos:5 | reply to nunya
Re: Drill bits Most people use speeds for drilling that are far in excess of the recommended feed rate. If you are getting 'chips' when drilling, you are using a speed that is too high. That is caused by 'chatter' at the material/cutting tool interface.
When the proper feed rate and pressure are used, the cutting will come off the material in a long coiled thread. If you use too much pressure, the bit will cut through the metal without making a complete hole. This is what shatters bits. Too much pressure also increases the heat generated, and that kills the temper of the bit.
Don't sharpen bits by hand on the grinder...get a Drill Doctor. A precise angle and precision cutting face are important to success. You'll know when to throw the bits away when you run out of flutes. 
It is also necessary to use a cutting lubricant when cutting metal. You don't need to flood the hole with lube. You need just a skosh. The Anchorlube is great in that it is not 'liquid' and it adheres quite nicely when cutting overhead. It cleans up without residue.
Most of the time Sparky just needs 'a hole', not a specific diameter hole. Use Lenox Vari-bits. They are quite robust if treated properly. The exception to that is, of course, when you are tapping holes. In that circumstance the proper numbered drill is highly recommended.
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No amount of force can control a free man, a man whose mind is free. You can't conquer a free man; the most you can do is kill him. Well, you can try to...
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| reply to nunya
Here is a post on another site about drill bits. Everybody seems to be impressed.
»www.garagejournal.com/forum/show···t=194077
new link to one of the sets.
»www.ebay.com/itm/Norseman-40614-···17480%26 |
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| reply to John Galt
said by John Galt:Too much pressure also increases the heat generated, and that kills the temper of the bit. It also work hardens the metal to be drilled exacerbating the problem. |
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lutful... of ideasPremium
join:2005-06-16
Ottawa, ON Reviews:
 ·TekSavvy DSL
2 edits | reply to nunya
said by nunya: NON-Chinese drill bit sets ... don't have to be made in USA - Swiss, German, etc... are fine. Consider drill bits manufactured in Canada and Brazil if you must avoid China at all costs.
Chinese companies essentially control the very best base material (molybdenum+cobalt hardened stainless steel) and majority of tool makers outside China mainly apply the coatings.
This site provides tips for different materials:
»www.wellsindustrial.ca/Resources···EEDS.PDF
convert SFM to RPM using info in this doc: »www2.mae.ufl.edu/designlab/Lab%2···eeds.pdf
Their main page (»www.wellsindustrial.ca/) has links to a few drill bit companies that meet your non-Chinese criteria. |
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