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Answers to your top 4 questions on using coolant in your Magnetic Drill


Coolant and cutting oils increase annular cutter tool life dramatically, up to 5 times and more! 

Many magnetic drills come equipped with gravity-fed coolant system that usually consist of the following: 

  • Coolant tank 
  • Tap on bottom of tank 
  • Control valve on bottom of tank 
  • Plastic feed line from tank to drill 
  • Nipple screwed into body of gearbox output housing 
  • Ejector pin  


How does the coolant tank on a Magnetic Drill work? 


As the cutter approaches the steel to drill a hole, the ejector pin is pushed up and this acts like a valve in the spindle. The spindle has a hole in line with the nipple and as the spindle spins it uncovers the hole and the coolant flows though from the tank. The pin has a slot along the length of it which allows coolant to flow down around the slug and to the cutting teeth. Centrifugal force ensures all cutting surface areas are coated with a layer of lubrication.  


What is the best coolant to use in my Magnetic Drill tank? 


The two main options are a neat oil or a water-soluble coolant (either mineral or semi-synthetic). With neat oil, you can use a lot less fluid because of the higher lubricity features. However, it is not great for cooling so not ideal if you are drilling numerous holes repeatedly as the tooling will get too hot and deform. 

Therefore, our most preferred option is soluble oil as it cools the cutting process as well as lubricates. This is ideal for most cutting situations as the oil applies lubrication and the water applies cooling. Lubrication is required to reduce friction and extend tool life, and the cooling to prevent heat affecting the martensitic structure of the cutters which can cause premature deformation or blunting.   


For neat oil, use the XDP 905 neat cutting and drilling oil 

For soluble, use the XDP 1000 coolant which mixes into a milky colour once mixed with water. We recommend you mix the coolant, 1 part of coolant to 10 parts of water. 


What happens when drilling horizontally or upside down? 


The biggest issue with the coolant tanks on Magnetic Drills is that they are normally gravity fed meaning that they can only be used for drilling upright. So, when drilling horizontally or upside down you will need to use either a paste or neat oil aerosol spray. We recommend to lubricate the cutter with a lube paste or neat oil applied by aerosol before drilling each hole. Excision has developed a special cutting paste (XDP 905 Paste) that is in a tube with brush – just squeeze a little bit of paste on to the cutter and you are good to start drilling. 


What if the Magnetic Drill doesn’t have a coolant tank system? 


If your drill is not equipped with built-in coolant system, it is best not to just squirt coolant on the cutter because it will just spin off during drilling instead of getting to the cutting teeth where it is needed. However, remember that any oil is better than none. In this instance, a good lube paste placed on the cutting teeth will do the job. Lube paste is a waxy substance that will adhere to the teeth of the cutting tool and will last for one hole. It should always be used when drilling in the vertical and overhead positions. (Excision XDP 905 Paste tube with brush is perfect for this Click here) 


By Jason Thomas

Published Apr 13, 2021 11:59 AM