BAB TIGA ( 3 )KIKIR ( FILE )<br />DISEDIAKAN OLEH :<br />HASNUL MUNAWAR BIN GHANI<br />POLITEKNIK JOHOR BAHRU<br />JABATAN KEJURUTERAAN MEKANIKAL<br />
FILE SHAPE<br />Flat file<br />* Cutting face are parallel to one another *cutting teeth on both edges *suitable for reducing to size and shape/ fit finishing<br />Mill file<br />* Thinner and smaller than flat file *have only one row of teeth<br />* Suitable in small slot<br />Hand file<br />* Teeth on only one edge * suitable in filling of a shoulder or internal edge of a square/rectangular<br />Square file<br />* Equal widths on each cutting face * suitable for enlarging square and rectangular cut-outs<br />Round file<br />* Also call as ‘rats tail’ * suitable for enlarging or elongating holes/for filling the inner diameter of tightly curved surfaces<br />Half Round file<br />* One face flat, other rounded* suitable in enlarging big diameter holes and same times use for filling gentle curves<br />Triangular file<br />* Teeth on all surfaces (including the corners) *Suitable for restoring threads and gear teeth, also for get a round file started<br />
TEETH<br />Rasp cutraised teeth used for cutting soft materials<br />Single cutthe file has a single row of teeth, making for smooth cuts<br />Double cuttwo rows of teeth arranged at an angle to each other<br />
Selecting a file for the job<br />1. Teeth coarseness :<br /> - too coarse <br /> 1) make very deep scratches<br /> 2) potentially take off too much material<br />- less coarse<br /> 1) will take longer time to do job<br /> 2) potentially safe way<br />File shape :<br />- large flat surface, pick widest file<br />- enlarging a hole, pick the largest round file that fit the hole<br />Try first before you file<br />
FILLING TECHNIQUES<br />Heavy filling<br /><ul><li>Used to removed a lot of material
One hand holds the file, other hand firmly grasps the other end.
File moved back & forth, with more pressure on push stroke than the return</li></li></ul><li>Light filling<br /><ul><li>Used for shallow cuts especially when approaching the marked line.
One hand holds the file, other hand holds the end with finger tips.
File moved back & forth, with light pressure.</li></li></ul><li>Draw Filling<br /><ul><li>Used for removing scratches left by the other filling techniques/polish the surface.
File moved back & forth, in the form of a cross .</li></li></ul><li>File Cards<br /><ul><li>Used on soft materials tend to clog, clean the teeth
Tiny metal chips caught in the file teeth may reduce efficiency of the file and may severe scratching the surface.</li></li></ul><li>CARE STEP FOR A FILE<br />Always have handle fitted to a file. Not only is the file then much safer to use, but it will also give you better control.<br />Never use a file as a lever or pry bar. The hardened steel is brittle and will snap.<br />Files are best stored apart so that their teeth are not touching.<br />In hot, wet environments, files can rust. To stop this occurring, give them a wipe over with a thin coating of engine oil.<br />If they are cheap enough, secondhand files are always worth buying. Even worn files can be used as final-finish tools.<br />