A Study direction milling affecting surface roughness by the Taguchi method with a 10 mm. bite milling cutter the direction of milling is clockwise G41 and counter clockwise milling. G42 is intended to measure the milling direction of the workpiece by testing with brass and aluminum materials. By measuring the milling direction the feed rate is 100 mm / min the speed is 1500 rpm and the depth of milling is 3 mm. The clockwise and counterclockwise hands provide better surface roughness and from the test the factors that affect the roughness of the surface are brass and aluminum. The coefficient of variation in surface roughness of the test specimens was 4 factors namely feed rate of 80 100 and 120 mm/min speed of 1200 1500 and 1800 rpm. The 3 4 and 5 mm workpieces are machined and the milling direction is divided into two parts: G41 clockwise bite counterclockwise G42 brass and brass material testing. It is found that the correct direction for brass milling is the direction of machining G41 with a cutting speed of 1200 rpm. The feed rate is 120 mm/min. And the depth of bite is 4 mm. The surface roughness of the workpiece is minimal. The surface roughness is 0.84 ?m. The optimum direction for aluminum milling is G42 cutting direction. The cutting speed is 1200 m/min. The feed rate is 120 mm/min. And the depth of biting is 5 mm. The surface roughness of the workpiece is minimal. The surface roughness was 0.75 ?m.

The objective of this work is to study the effect of the surface roughness on the measured hardness. The preparation of the surface roughness level complied with the ISO 1302: 1992 standard. There are many factors influencing surface roughness such as building mac uncry feed rate speed machine settings cutter and water cooling. The surface roughness C.tU. by these factors will have influence on the measured hardness of materials. The SKS3 is used as material in this study. Surface of the work piece was adjusted with different roughness val es divided following four levels: 12-50 urn rough machined 1.6-6.3 urn smooth turned 0.2-0.8 urn and 0.025-0.1 um. Then all the adjusted roughness work pieces were harden. After the Harden process the hardness of all work pieces were 62-64 HRC. From the measured hardness results it was found that the standard deviations are 4.665 1.0310.530 and 0.407 respectively with surface roughness value. Therefore it can be concluded that the standard deviation of hardness increased when the surface roughness increased