Drill Magnetism Question?

bcall2043

bcall2043

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I have been finding a few drill bits at the scrap yard recently. The drills were mostly found in the punch press chip piles from local manufacturing company. Some of the drills look alomost new (see photo) and some need to be resharpened. They are labled HSS, made in USA and the brand is Nitro, catalog link: http://www.preferred-drillbits.com/download/20.pdf

Nitro Drill.jpg
The big issue I see with the drills is they have become magnetized from being handled by the large magnetic crane lifts at the scrap yard. The drills want to stick to all things steel. Note in the photo the drill was wiped with a paper towel several times and steel-fuzz remains. I think (but not sure) this could be a problem in use. I have a demagnetizer that came with a surface grinder but have never used it. The one I have looks like the Model #285-2505 in the ENCO catalog link below. Not sure if mine is the same since it is bolted to the grinder and I can't see the model tag.
http://www.use-enco.com/CGI/INSRIT?PARTPG=INLMKD&PMPXNO=949785&PMAKA=285-2505

First question is should these drills be demagnetized before using and will a demagnetizer like what I have do the job? If the answer is yes then how do I use the demagnetizer? I don't have a manual and have never used one.

Benny
The Orphanage Never Closes

Nitro Drill.jpg
 
Not sure but I think the curie point is lower than the temper point, so you might try heating one up gradually until it loses magnetism, and then use it and make sure it hasn't annealed.
 
Have the same unit at work.

First thing, remove your watch! Keep the unit away from anything that could be affected by the magnetic field. Like digital mic, the above mentioned watch etc.

Turn on the demag and bring the drill bit into near contact. You do not need to touch them together, unless of course you like the buzz sound that will make.

Move the drill away from the the demag until it is arms length away, turn off the demag.

Do not turn off the demag while the bits are close to the unit, that leaves a residual magnetism that is the same as the last pulse that the demag put out.

You should have removed the residual magnetism from the drill.

Tape is a good remover of stray chips.
Pierre
 
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yes demagnatize your drill bits, Just put them on the demagnetizer in bulk and turn it on. Pull them off the magnet and in seconds it will be all done. Just a note. You can take any AC coil from say, a solenoid, fish tank aeriator, hair clipper, relay, etc. Then solder a cord on it and tape it up, it will make a fine demagnetizer. For free.
I HATE MAGNETIZED TOOLS. what a pain.
 
pdentrem said:
Have the same unit at work..

Turn on the demag and bring the drill bit into near contact. You do not need to touch them together, unless of course you like the buzz sound that will make.

Move the drill away from the the demag until it is arms length away, turn off the demag.

Do not turn off the demag while the bits are close to the unit, that leaves a residual magnetism that is the same as the last pulse that the demag put out.

You should have removed the residual magnetism from the drill.

Tape is a good remover of stray chips.
Pierre
Click to expand...

Pierre,
Thanks for the instructions. They worked perfectly.

Today I have learned to use another tool that was just setting there collecting dust and I have some new looking drills. The remaining steel-fuzz wiped off easily. Just need to check and make sure the drills are not bent and ended up in the scrap for no real good reason. I am kind of eager to use the drills for something. They are split points and I have never used a drill with this type of tip grind.

One last question, do you know how large of a part the demagnetizer can handle? I would assume that the part should be able to fit onto the stainless steel top of the demanetizer, correct?

Benny
The Orphanage Never Closes
 
Benny
Actually, as long as it fits in the field that the demag makes, it fits. You can pass long, oversized, fat pieces by just moving it around inside the mag field and you can do just about anything.

The way it works, it is demagnetising or degaussing by simply creating an alternating magnetic field, of N and S poles. As you move the steel part further away from the unit, the field strength drops off until it reaches nearly zero, and the steel part also drops to zero as well.

You can make steel magnetic by turning off the unit while the steel part is next to it.

You can make your own as stated above, by using a wire winding and AC power.

Everybodies old style color tube TV set had one built in, it was wrapped around the tube, usually close to the screen end of the tube. It keeps those funny colors from occurring over the life of the screen. I have used a hand held unit to "fix" TVs that people had placed unshielded speakers too close to their sets and caused color shifts in the areas closest to the speakers. Sometimes the built in coil would not work due to being of lower power, but usually just removing the speakers and over time the colors would return.
Pierre
 
pdentrem said:
Benny
Actually, as long as it fits in the field that the demag makes, it fits. You can pass long, oversized, fat pieces by just moving it around inside the mag field and you can do just about anything...........
Pierre
Click to expand...

Pierre,
Thanks for the quick answer. I will have to remove it from the grinder frame to use it for long parts but it is good to know what it can do. One of the pitfalls of picking materials from the scrap yard is the big crane magnet they use to unload and move materials can cause residual magnetism in some of the harder materials and tools. I can see the information you provided being useful.

Benny
The Orphanage Never Closes
 
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