How To Operate Tungsten Carbide Drill Bits?

When comparing a tungsten carbide drill bit to a regular or high-speed steel drill bit, the tungsten carbide drill bit feels heavier. When grinding it on a regular gray grinding wheel, the sparks from the tungsten carbide drill bit are dark red and it's difficult to grind, while the sparks from a regular or high-speed steel drill bit are brighter. Tungsten carbide drill bits are brittle; if dropped, the cutting edge will easily chip. Other drill bits won't chip in this way. Tungsten carbide drill bits possess a series of excellent properties, including high hardness, wear resistance, good strength and toughness, heat resistance, and corrosion resistance. In particular, its high hardness and wear resistance remain largely unchanged even at 500°C, and it still maintains high hardness at 1000°C.

Tungsten Carbide Drill Bits

Tungsten carbide drill bits are tools used to drill through holes or blind holes in solid materials, and can also be used to enlarge existing holes. Common types of tungsten carbide drill bits include twist drills, flat drills, center drills, deep hole drills, and core drills. While reamers and countersinks cannot drill holes in solid materials, they are conventionally classified as drill bits. So, how should we operate tungsten carbide drill bits, and what precautions should we take?

I. Chip Management:

When machining with tungsten carbide drill bits, it's undesirable for the chips to be discharged in a long continuous strip. Especially when machining materials with high toughness, excessively long chips can cause chip clogging, damaging the tool. In this case, the feed should be stopped, the chips removed, and then machining resumed. This method is called staged feeding.

To break the chips, metal shims can be installed in the chip flute of the tungsten carbide drill bit.

II. Drill Bit Diameter and Drilling Depth

The standard drilling depth is approximately 5 times the drill bit diameter. If it's a type with brazed tungsten carbide inserts on the shank, the depth can reach 7-8 times the tungsten carbide drill bit diameter. Of course, in that case, chip management is very important. III. Use of Guide Bushings

When the work surface is uneven, to prevent the drill tip from vibrating and damaging the cutting edge, use a guide bushing whenever possible to ensure that the tungsten carbide drill bit enters the workpiece in a straight line.

IV. General Standards for Hole Diameter, Hole Depth, and Tool Selection

For a hole diameter of 20mm and a hole depth of 12mm, a twist drill can be used; for a hole depth of 15mm, a long drill bit should be used; and for a hole depth of 50mm, a gun drill or an opening tool from the BTA tool system should be used.