The sides and bottom of the keyway should be surfaced true with the file. If a keyway is to be cut by hand through a bore, as in a pulley or gear-wheel bore, its width should be marked with a T-square. This head is also driven by a key which engages a keyway in the boring-bar. The rod end should be planed to thickness for the brasses and of equal thickness on each side of the keyway. The flat key is used where it is necessary to secure the wheel more firmly without weakening the shaft by cutting a keyway in it. A much more usual method, however, is to employ slotting or keyway drills.
 Igneous, metamorphic, and sedimentary are descriptive terms used to  classify types of rocks, not minerals su â¦ ch as diamond.     Diamond is accepted as a valid mineral by the International  Mineralogy Association.
Making the world better, one answer at a time. An igneous rock is a rock that started as molten magma then cooled and solidified either above,on,or below the surface. An sedimentary rock is a type of rock that is formed by sedimentation of material at the earths surface and within bodies of water.An metamorphic rock is the result of the transformation of an existing rock type, the protolith, in a process called metamorphism, which means ''change in form.he particles formed are then be redeposited to form new sedimentary rocks. To form an igneous rock out of a metamorphic rock you need have conditions in the Earth that will raise the temperature high enough to form a melt out of the rocks. This melt (magma) can then form new igneous rocks.