How to drill a hole in Hardox® wear plate

Geposted von Adam Smith am

drilling hardox

Metals like Hardox®, Inconel®, Stainless Steel and Armor plate are notoriously hard to drill or machine.

Wear plates and abrasion resistant steels made from these materials are typically up to 5x harder than standard S275 structural grade steel and are often used in industries that require extremely tough equipment such as aggregate and waste processing or mining and excavation.

Whilst this abrasion resistance is highly prized in these specialist fields the material’s extreme strength and durability provides a real challenge for the majority of cutting tools, especially when the application requires the use of portable drive tools like magnet drills.

Drilling hardox with a magnet drill

So how do you drill a hole in materials like this?

Drilling holes in Hardox® and other similar wear plates is a specialist task and requires the right equipment and setup.

High torque, slow speed, geared magnet drills, like the VersaDrive series from Holemaker Technology, and ample Biocut blue lubricant are essential.

In addition, the correct cutting tools are also required, and HMT have developed a generation of ULTRA cutting tools for exactly this purpose.

Coated with an extremely hard-wearing compound of powernitride these specialist cutters are capable of providing a service life in excess of 9x longer than standard uncoated TCT tools when working with materials like Hardox®, Inconel® and more.

They are also tipped with individually brazed cutting teeth of the highest quality carbide and have been designed with an elaborate cutting geometry which results in faster, quieter, easier drilling and chatter free performance.

hardox cutter ultra broach cutter by Holemaker Technology

The Method:

It should be understood that even with high tech tooling, successfully machining Wear plates is challenging with little or no margin for error. It requires experienced operators, quality, premium Magnetic Drills suitable for these applications, and the specially developed BioCut Blue cutting fluid when broaching or Speedlube Aerosol spray when countersinking.


broaching hardox

Equally as important though is the method used for making the cut.


When Broaching -

To achieve best results and ensure the optimum life of the tooling used:


  • Cautious & Gentle feed pressure should be used at all times, especially during the start of the cut and exiting the material
  • Generous application of Biocut Blue cutting fluid should be used during the cut & applied frequently during the cut
  • Backing off the cutter & applying more BioCut Blue is necessary for increasing tool life
  • Swarf removal from the cutter is also required for longer tool life


countersinking hardox

When Countersinking –


  • To achieve best results the countersink must be piloted
  • Do not allow the countersink to vibrate over swarf while cutting as this will cause chatter, ultimately causing the cutting edges to chip & blunt
  • Regular Speedlube application & regular swarf removal on countersinking is essential
  • A hand brush works better than mag stick to clean cutter and material surface

Even with the above techniques and correct cutting tools it is important to note that using an incorrect or poorly maintained magnet drill with unstable drilling operation or poor magnet hold is likely to result in rapid tool failure. This is equally as true if using excessive pressure or inadequate lubrication during the cut.

Assuming the correct equipment and techniques are employed though, ULTRA cutters by Holemaker Technology can increase tool lifespans by up to 9x times that of standard tools and are the only choice for the professional metalworker.

Tools and Sizes Available:

ULTRA Coated CarbideMax 55 TCT Cutters
12 – 26mm
Shank Size = 19.05mm
Additional sizes available on request

hardox broach cutter

ULTRA Coated Multisink
40 & 55mm
90° point angle
Shank size = 19.05mm

hardox countersinking tool

Test Results comparison


Tool used

Holes Completed

Machine Used

Test at (no Load) RPM





Uncoated 18mm HMT CarbideMax TCT Broach Cutter


HMT VersaDrive V60T

390 RPM





Coated 18mm CarbideMax ULTRA TCT Broach Cutter


HMT VersaDrive V60T

450 RPM

Coated 22mm CarbideMax ULTRA TCT Broach Cutter


HMT VersaDrive V60T

410 RPM

Coated 26mm CarbideMax ULTRA TCT Broach Cutter


HMT VersaDrive V60T

390 RPM





40mm ULTRA Coated TCT MultiSink


HMT VersaDrive V125T & V60T

110 + 160 RPM


It should be noted that these test results were achieved by an experienced operator using a high quality and well maintained magnet drill. Used incorrectly or with inappropriate equipment it is possible that tool failure could occur significantly earlier.

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