Magnatize

Could some of you kind gents please tell me how I can magnetize the end of a
.500 bar of drill rod?
Regards. Ben
Reply to
Rotty
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Wrap any insulated wire around the rod 20 or more times & connect it to your car battery for a half second. Best to use jumper cables so you do not make a spark near the battery, because you could blow it up!
Rotty wrote:
Reply to
Ralph Henrichs
Stroke along the length of the rod in one direction with a powerful permanent magnet. Or wrap a coil of wire around the rod (solenoid coil) and apply a large DC current to the coil for a short period of time.
For mild magnetization, align the rod with the flux lines of the Earth's magnetic field (Point to the North magnetic pole at a slight dip angle depending on your location) and strike the end of the rod with a hammer a few times.
Reply to
Russ Haggerty
Thanks for the information, I will give that a try tomorrow, many thanks. Ben
Reply to
Rotty
On top of the good suggestions you received, I would suggest that you use a compass to measure the strength of the magnetic field in the rod. All you do is to bring the compass near the rod until the needle starts to be influenced by the rod's presence. The further away the rod will effect the compass, the more powerful of a magnet you have created.
Just a thought.
Reply to
Rileyesi
I don't see this working. I've dropped my centerpunch and countersink among other tools many times, pointing E-W and they are still magnetized (from a past magnet contact). Or is it that they are magnetized across the axis?
Tim
-- "I've got more trophies than Wayne Gretsky and the Pope combined!" - Homer Simpson Website @
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Reply to
Tim Williams
You can not demagnetize an item by orienting it 90 degrees to a magnetic field and remagnitize it a little bit. To demagnetize you must use a diminishing fluctuating AC field around the object. Wrap your punch with a coil of wire and apply AC with a rheostat and gradually turn the current down to zero then remove the punch from the coil.
Reply to
Russ Haggerty
Better use 14ga or heavier lest it catch fire. Add a short length of 18ga in series with the leads to act as a fuse. You are likely to spot weld the circuit closed so you need safety. Do the experiment in a well ventilated area.
Try to complete the magnetic circuit by attaching a peace of iron between two intended poles. This will make the magnet stronger.

Regards,
Boris Mohar
Got Knock? - see: Viatrack Printed Circuit Designs
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Reply to
Boris Mohar
Take a junk hard drive apart for the rare earth magnets. Stroke one of these magnets the length of your drill rod. It will end up slightly magnetized.
If you needed a powerful magnet then glue a disc rare earth magnet to the end of your drill rod, stuff is brittle though.
Reply to
Beecrofter
He said "mild". Earth's field is only about 0.5 gauss. Saturation flux density in drillrod is probably at least 10,000 gauss (10 tesla).
Reply to
Don Foreman
Greetings and Salutations...
from the "end" remark it sounds as if you do not want the entire thing turned into a magnet...so how about this. Get one of these slick, rare-earth magnets that is half an inch in diameter and epoxy it to the end of the rod. Between the glue and the normal magnetism of the thing, it should stay there for a LONG time. Of course, it kind of matters what you want to DO with it too. if it is to be subjected to stress or heat, perhaps it would be better to get a 3/8" diameter magnet and recess it into a hole in the end of the bar. Put it in place with epoxy or loc-tite (I KNOW that is epoxy,, too, by the by) and it should be good to go.
Regards Dave Mundt
Reply to
Dave Mundt
Ouch! Silicon steel (grain-oriented, i.e. GOSS, even) saturates around 1.2T. And that's pretty much the best stuff out there, which happens to be why it's found in transformers. Mild is around .6 or .8T. Carbon steel even less, plus it has dramatic hyteresis losses (with the side effect of holding a magnetic field, something mild steel does extremely weakly, at least HRS).
BTW, Earth at the surface (average?) is 1 gauss (100uT).
However, permeability of a good silicon steel passes 10,000 (toroidial transformers easily 40k), but that's mu, not gauss.
Tim
-- "I've got more trophies than Wayne Gretsky and the Pope combined!" - Homer Simpson Website @
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Reply to
Tim Williams
Tim, Take a LONG thin screwdriver, say about 8" shank and 1/8" diameter and smack it down on the top of your vise a couple of times (it doesn't really matter much which way you're pointing) and you will be able to pick up small screws with it..... Ken.
Reply to
Ken Sterling
Another way is to wrap some small insulated wire around the shaft and hold each end (bare) to the batt electrodes in your car. Pretty strong magnetized driver after that...
Reply to
Spike
Oops! You're right, I slipped a decimal there. I should have said 1 Tesla, not 10, and you may be right about carbon steel being lower. My point was merely that orienting it and hitting it with a hammer won't make a very strong magnet -- which is in agreement with your observation about the dropped center punches.
Hysteresis is not loss when "magnetizing" something. It's hysteresis that makes it possible to (permanently) magnetize it.
BTW, Earth's field varies from 0.3 gauss to 0.6 gauss (30 to 60 uT). See
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's_magnetic_field
Reply to
Don Foreman
- Er, loss when used in transformers, that is.
Ah. Also:
"The deterioration began roughly 150 years ago and has accelerated in the past several years. So far the strength of the earth's field has decreased by 10 to 15 percent."
Maybe that's what I was remembering. Or now that I think of it, it might be half that I heard after all.
Tim
-- "I've got more trophies than Wayne Gretsky and the Pope combined!" - Homer Simpson Website @
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Reply to
Tim Williams
That had already been discussed, but Tim was doubting that you could magnatize by striking with a hammer.....
Reply to
Ken Sterling

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