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.
rocks can be put into three fundamentally different types igneous sedimentary and metamorphic rock igneous rocks are crystalline solids that form directly from cooling magma where magma is molten rock made by partial melting of rocks in the earth s interioredimentary rocks are secondary rocks as they are formed from the accumulation of small pieces of pre existing rock that is parent rock there are two main types of sedimentary rocks based on the source of the sediment sedimentary rock can form as solid particles from weathered rocks