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Never Use Magnets To Lift Wear Plate

A longtime metal recycling customer called saying he was having an issue for the first time welding our QT-Plus ® wear plate. This was a surprise since QT-Plus ® was designed to be easy to weld.


He explained the welding arc was nearly uncontrollable, “It is dancing all over the place.” I said, “It sounds like you have magnetized the steel plate.”


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Fabricating their own scrap metal recycling bin, the welder had difficulty welding the stiffener channels onto the wear plate sides.




When I arrived, we looked at the bin he was working on and he showed me how the arc danced all over and wouldn’t allow for a good structural weldment where it was needed.


Experimenting by welding above and below the area he could weld, but not for a section about 24” long close to the center of the plate. It was clearly magnetized.



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Scrap yards use high powered electromagnets to pick up scrap that remains after car bodies have been run through the shredder. With the power on, the steel scrap literally jumps up to the magnet. When the power is turned off, the scrap falls into the railroad cars or semi-trailers to go the foundries or steel mills to be recycled into new steel. Click Here for more info on scrap magnets.




When asked if they unloaded the semi load of wear plate with the electromagnet, he said he didn’t think they did. After checking they verified it had indeed been unloaded with the mobile magnet.


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The yellow circle shows the steel was so magnetized, it was able to hold a 10” long ½ -13 bolt on the vertical side of the plate! This is a close up of the first photo above.




He was confused because they frequently unload mild steel plates and tubing with the magnet, and had not had any issues in the past.


Why Did The QT-Plus ® Become So Magnetized?


Mild steel does not contain any alloying elements such as Nickel, Chromium, Molybdenum, Vanadium, Boron, etc. As a result it is not overly magnetic.


QT-Plus ® on the other hand has high levels of Nickel Chromium and Molybdenum. Heat treating steel containing these alloys; make the steel wear plate hard through-out the thickness of the steel.


It is also the same alloying elements which can become very magnetic when lifted with an electromagnet.



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Use special plate lifting clamps and be certain your hoists are properly rated for the load you are moving.




What If My Wear Plate Is Already Magnetized? How Can I Weld It?


There is still hope. What you have to do is de-magnetize the area.


Loop the cable attached to your ground clamp several (4 to 5) times around the area to be welded. This sets up a different magnetic field and reduces the residual effect on the steel.


In this case the area was on the side plate, with the box mostly assembled. How can you have the ground cable loops stay in the required area? He tacked a couple bolts above and slightly to the sides of the plate. Using them like a coat hook, we hung the ground cable loops so they were able to offset the magnetic field and allow the weld to be completed.


NEVER USE MAGNETS TO MOVE WEAR RESISTANT STEEL


For over the last 40 years JADCO has focused exclusively on delivering consistent, longer equipment life for our customers.


Now you understand why we are able to deliver better results to our customers. We think differently by strictly focusing to improve your current results.


Allow us to help you today by calling (724) 452-5252, or email info@jadcomfg.com.


We will schedule a meeting with one of our local wear plate specialists at a time that best fits your schedule.


Remember, the only thing you have to lose by not working with JADCO, are your profits.


When your standard AR wear plate gives out, give JADCO a shout! (724) 452-5252