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Solid Carbide Drill for Drilling Depths 20 x d

5 versions of Inox-Drills with through tool cooling are available for hole depths from 3 x d to 20 x d in the diameter range from 1 mm to 6 mm.

Compact, short and bent chips are a characteristic when drilling with CrazyDrill Cool SST-Inox (at the right the "classical" chips of SS drilling.

The special cross section of the coolant ducts provides four times more coolant flow compared to conventional round cross section ducts.

A massive cooling of the drilling process is instrumental when drilling stainless materials without pecking with aggressive cutting parameters

CrazyDrill Cool SST-Inox is a solid carbide drill, available in the diameter range from 1 mm to 6 mm, was developed by Micron Tool for the machining of stainless steels, heat resistant alloys (nickel based) and chrome-cobalt alloys. After the 2016 launch of the short versions of 6 x d and 10 x d, this type of tool is now also available for drilling depths of 15 x d and 20 x d.

Mr. Schnyder, responsible for initial development at Mikron Tool International, spoke about the particularities of the new product. He pointed out that the development engineers were quite challenged by the difficulty of evacuating chips out of the long spiral flutes. Mikron Tool was able to build on the geometry of the short version of these drills and its "chip breaking profile" at the front of the tool, which creates short and bent chips. Added to this they used an enlarged flute profile in the rear section of the flute that provided massive and constant cooling and chip evacuation. However, an additional measure was required for these drill lengths: the polishing of the flutes. The smooth surface of the spiral flutes represents a significant difference when drilling more than 10 x d. Hence both features together provide even force requirements when drilling deep. Therefore, a single feed stroke is sufficient to reach the full drilling depth and a dependable flushing of the chips from the flutes. And all this with high feedrates and speed rates.

Maximum Cooling Performance

An additional characteristic, necessary for machining stainless materials safely and with high speeds, is efficient cooling. The Inox-Drill from Mikron Tool has spiralized and in the drill integrated cooling ducts that deliver the coolant right to the drill tip. These ducts have a cross section in the form of a drop, which differentiate them from the usual round cross section. The distinct advantage of these ducts is that they deliver up to four times more coolant volume. To ensure this cooling performance also in small drill diameters, the shank is equipped with an additional Power Chamber (a cavity in the shank). This high cooling performance avoids the overheating and subsequent chipping of cutting edges and build-up of material.

Short Drilling Cycle, Long Tool Life

Schnyder said, "These newly designed drills are very reliable and tool life can be significantly extended, especially when machining heat resistant alloys. This means that the user can produce valuable workpieces with high process reliability. An example: a manufacturer of steam valves made from stainless austenitic steel DIN 1.4301 (AISI 304), which are used in coffee machines, performed with one CrazyDrill Cool SST-Inox O 2.75 mm a bore with a depth of 15 x d in one single feed stroke, and this by achieving a tool life of over 100,000 parts. This is double what was reached before. Tests have shown that depending on material, up to three times better tool life can be reached. The time factor represents a big potential for savings. First tests show that a hole depth of 20 x d drilled in one shot with the recommended cutting parameters can take 10x less time than usual. Even our researchers were surprised that it is possible to operate with the same feeds and speeds, independent of whether the hole is 6 x d or 20 x d."

Quality with a Clear Drilling Process

"In order to obtain good drilling quality with these drills, it is recommended to adhere to the manufacturer recommended guidelines. The manufacturer confirms that these are all results tested in manufacturing environments. Hence for a depth of more than 6 x d a pilot drilling is necessary, preferably a CrazyDrill Coolpilot which was developed as a complement to the CrazyDrill Cool SST-Inox. This tool has been harmonized with the deep hole drill in its dimensions and tolerances. Also, speeds and feeds should be chosen within the recommended range. With this a maximum quality of the hole is assured in regards to cylindricity, axis runout and surface quality," said a company spokesperson.

For more information contact:

Mikron Corp. Monroe

200 Main Street

Monroe, CT 06468


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