Register or Log In To remove these advertisements. |
|
|
|
Thread Tools | Display Modes |
|
06-12-2019, 02:03 AM | #1 |
Registered User
Join Date: Nov 2013
Location: Show Low, Arizona
Posts: 764
|
Re: question about metal for machinists
For the most part, using cutting oil when you are hand drilling just serves to help you clear chips out the flute of the bit. It is very unlikely you put enough heat into the fastener to 'heat treat' it
A lot of larger bits have a chisel point in the middle and only work well with a pilot hole. Did you run out of pilot hole? I start mine with a sharp 1/8" bit all the way to the bottom of the hole. While it'd be almost impossible to change the hardness of the fastener, you can dull a drill bit pretty fast by overheating it at too high of RPMs and putting a drop or two of oil on it isn't going to make much difference. Different drill bit brands will have different coatings and materials and one might be more robust to higher speed than the other. Look at the cutting edge of the bit and see if there's chunks missing out of the cutting edge or it is a straw color. Learn how to sharpen a bit on your grinder or buy yourself a DrillDoctor. |
06-12-2019, 12:18 PM | #2 |
Registered User
Join Date: Feb 2019
Location: Ozark, MO
Posts: 575
|
Re: question about metal for machinists
Cutting oil keeps the temperature down, not increases it.
But a drop will not do that. When you look at machining, the cutting fluid is pouring on the tool and cutting piece to wash away the chips and cool. There is some new high tech cutting fluids, that do only use a mist. Keeps the machining chips cleaner so worth more as scrap, plus reduces amount of cutting oil purchased and used, which is expensive - oil!!!!!. But they are only for aluminum - aerospace especially. I am retired mechanical engineer who worked most of my career at John Deere and Mercury Marine with background in machining steel and aluminum. |
06-12-2019, 12:25 PM | #3 |
Registered User
Join Date: Feb 2019
Location: Ozark, MO
Posts: 575
|
Re: question about metal for machinists
Forgot one comment. Sorry.
Mongocanfly gave the correct answer. |
Bookmarks |
|
|