Magnetic Tool Holders for Cutting Tools

Highland Woodworking just had an “ask the staff” question in their recent newsletter regarding how magnetic tool holders affect sharpening.  The staff member presented a reference to a sharpening book that relates that there is a  “process called magnetic fluxing. This process relieves the stress level of the metal through magnetic bombardment and, as a result, extends the useful life of the tool.” The staff member goes on to quote, “some cutting-tool users have long recommended magnetizing tools because it increases the modulus of elasticity of the tool, extending its life.”   He wraps up the advice by saying that he is not sure if the magnetic strip is strong enough to sufficiently magnetize the tool to extend its life.

This is no dig against Highland Woodworking.  I like the company, and I like their newsletter and their advice.  However, in this case, too little research was done.  This happens a lot in the case of magnetism because most people just sort of gloss it over like some sort of magic.  As a former physics teacher, this glossing over makes my skin crawl.  (Similar to when people talk about saving power … power, it is a rate, you can’t save it any more than you can save speed.) The problem in this case is that magnetic fluxing is being portrayed as  similar to using a magnet to hold a tool to a wall.  They both have the word magnet in them, but the similarity ends there.

The kind of magnetic fluxing that leads to stronger steel is a process applied when the steel is cooling from being forged.  It has to be a very intense, pulsating magnetic field (one so strong that it actually alters the phase change temperature of the steel).  [reference]  This has almost nothing in common with using a relatively weak and stationary magnet to hold a relatively cold tool to a wall.

I am not a metal specialist, nor a sharpening specialist, but here is my experience with magnetized tools.  I have a handful of screwdrivers, a pair of pliers and a chisel that have all been either accidentally or intentionally magnetized in their lifetime.  I can always tell which ones they are because there are always little bits of iron stuck to the end of them.  Having to remove the little bits in order to use the screwdriver is sometimes a hassle.  Keep in mind, that the magnetic field of any magnet is strongest at the poles, and the tip of the screw driver and the tip of the chisel become one of the poles of the magnet.  Also keep in mind, that the more pointed the end, the more concentrated the magnetic field is.  So in the case of my one poor chisel, the cutting edge is the strongest part of the magnet, which means the cutting edge attracts all the bits of iron it comes near.

Just the act of wiping off the iron flecks dulls the edge a bit…. no problem, just sharpen it, right?  So I head to my sandpaper and glass and start trying to sharpen it,  as the sandpaper abrades the metal from the chisel where does it stick?  Right back to the cutting edge of the chisel where it prevents a near perfect union of two intersecting planes from ever forming.  This particular chisel could be demagnetized, but it is a beater of a chisel and I haven’t bothered with demagnetizing it.

magnetic chisel blade

Here is my poor magnetized chisel blade attracting iron bits and dulling its potential.

I see no benefit to this tool being magnetized.  For this reason, I keep all of my edged tools away from magnets, even though it would be really handy just to stick them to a magnetic holder .  I also keep this magnetized chisel in a different location than my other chisels.  I don’t need it rubbing off on them.

I will add for accuracy that some magnetic tool racks are more likely to magnetize your tools than others, but I’ll have to save that explanation for another time.