Cutting and drilling tools

At the simplest level, nanoparticles of hard substances are useful as polishing powders which are able to give very smooth, defect-free surfaces. Indeed, 50 nm nanoparticles of cobalt tungsten carbide are found to be much harder than the bulk material. Therefore, they can be used to make cutting and drilling tools that will last longer. 

Figure 6.49 Examples of cutting and drilling tools coated with CVD diamond ( L. Schafer).

When the lattices of various metals are expanded by the presence of carbon atoms, the interstitial carbides result. These materials retain many metallic properties such as high conductivity and luster, and often are harder and melt at higher temperatures than the pure metals themselves. The addition of carbon to iron makes steel, but too much carbon makes it brittle. Tungsten carbide, WC, is used for cutting and drilling tools. 

Preservatives are widely employed in cosmetic preservation for lotions, creams and shampoos. Preservation is also an important aspect of formulation in emulsion paints and cutting fluids, i.e. fluids used to cool and lubricate lathe and drilling tools. 

When we think of diamonds we think of sparkling jewellery. Diamond has other important uses. Diamond tipped tools are used for cutting and drilling rocks. It is used in spacecraft to make radiation proof windows. 

Tungsten carbides are used in cutting and forming tools, for example, in rock drills and machine tools. 

Tin plate, wire, rivets, pipes Ship and boiler plates, structural sections, turbine rotors, marine shafts Railway rails, crank pins, connecting rods, axles, gears, gun barrels Locomotive tyres, woocteutting tools, crusher rolls, hammers, hand chisels Car springs, tap drills, ball races Metal cutting and forming tools, drills, wire dies... 

In a more recent development a new wireline tool has been developed that actually drills a plug out of the borehole wall. With sidewall coring (Fig. 5.36) some the main disadvantages of the SWS tool are mitigated, in particular the crushing of the sample. Up to 20 samples can be individually cut and are stored in a container inside the tool. 

Drill Pipe Wear. Erosion can occur between the hard band and the tool joint metal when the box end is hardbanded. This erosion is due to the high-velocity flow of cuttings in the annulus section of the borehole. 

Key seats occur in dog legs of the borehole. The drill pipes cut a groove in the wall at their dimension and when tool joints or drill collars are pulled up, the drillstring gets stuck. 

Cable-tool drilling works in much the same way as a chisel is used to cut wood or stone [1]. A steel cable repeatedly drops and raises a heavy cutting tool called a bit. Bits may be as long as 8 feet (2.4 m) with a diameter of 4 to 12.5 inches (10-31.8 cm). Each time the bit drops, it drives deeper and deeper into the earth. The sharp edges of the bit break up the soil and rock into small particles. From time to time, the workers pull out the cable and drill bit and pour water into the hole. They then scoop up the water and particles at the bottom of the hole with a long steel tool known as a bailer. 

Cut-off tools and small drills are more hazardous because of the poor cooling conditions. These operations, if necessary, should be performed at low speeds with intermittent cutting and frequent flushing. Water should be used wherever practical as a coolant, although tests at high speed under dry conditions are... 

Diamond is one of the hardest known substances and because of its props is used to cut glass minerals, in drilling tools and as... 

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