Drilling holes in Armox

Drilling holes in Armox (370T, 440T, 500T, 560T and 600T) should not be a problem. Armox is used as armor plate, ballistic protection of vehicles or machines for defensive purposes. The Armox plate is usually not thick, but very hard. Armox 600T is the highest class of armor and is – due to the hardness of the material – on the limit of what is technically possible with solid carbide drills.

Choice of drill

Various drills are available for drilling in Armox. The best option is a solid carbide drill with internal cooling on a CNC machine. Not only is this the most efficient method, but considerable tool life can also be achieved in this way. If no CNC machine is available, a cobalt drill (HSCo) can also be chosen. Most cobalt drills in the Dormer Pramet range have a cobalt content of 8%.

Below is an overview of the drills that are suitable for drilling in Armox:

Solid carbide drills

Without internal cooling:

• R520 : This CDX drill has a convex cutting edge and a thick core for extra strength. This makes this drill optimal for use in CNC and hand-operated machines that do not have internal cooling. The dimensions are according to the short DIN 6539 version. The top angle is 130 degrees. These drills are available from 3.0mm to 16.50mm.

• R510 : Same drill bit as above, but in a longer DIN 338 version. Available from 3.0mm to 14.25mm.

With internal cooling:

• R457 : This MPX drill is used on CNC machines with internal cooling. The dimensions are according to the short version DIN 6537 – 3xD. The apex angle is 140 degrees. Available from 3.0mm to 20.0mm.

• R453 : Same as above, only according to the longer version DIN 6537 – 5xD. Available from 3.0mm to 20.0mm.

Cobalt Boren (HSCo)

• A117 : Short HSCo drill (8% cobalt content) according to DIN 1897 with a top angle of 135 degrees. Available from 2.50 mm to 13.00 mm.

• A777 : Normal HSCo boron (8% cobalt content) according to DIN 338 with a top angle of 135 degrees. Available from 0.30 mm to 16.0 mm.

• A730 : Morse taper HSCo drill (8% cobalt content) according to DIN 345 ​​with a top angle of 118 degrees. Available from 10.00 to 32.00 mm

Method

Drilling holes in Armox should not be a problem when the right tool is chosen. It is also important to pay attention to the following:

• Use sufficient coolant or emulsion. Armox is very abrasive to a drill. Abundant and high-quality lubrication improves tool life. The use of a solid carbide drill with internal cooling is therefore preferred.
• Do not interrupt the drilling process! Interrupting the drilling, for example to check how deep the drill is, can cause problems. Not only will it be difficult to resume the drilling process without difficulty, each new start means extra wear on the drill. So drill the hole in one go with sufficient cooling and lubricant, as well as the correct cutting data, for an optimal result with minimal wear on the drill.

So drill the hole in one go with sufficient cooling and lubricant, as well as the correct cutting data, for an optimal result with minimal wear on the drill.

Tips and recommendations

• Use 20 bar pressure for the internal cooling. If the pressure for internal cooling decreases, the cutting data must be adjusted downwards.
• Use the correct machining conditions appropriate to the circumstances. The higher the armor class, the lower the cutting data due to the increasing hardness of the material.
• Preferably never pre-drill Armox, only lightly center with the correct top angle if desired
• Ensure a stable and reliable machining process.
• Consider your safety and that of others. Use the required protective equipment.