STUDY OF IMPORTED BOLT MATERIAL USED TO TIGHTEN EQUIPMENT IN CEMENT FACTORY

Aim of the research is to study the mechanical prop erties and microstructure of imported bolt material used to tighten a lifter liner in tube raw mill of cement industry. Results of the investigation are very necessary as reference espec ially for local industries interested in producing of the bolts. Production of such bolt has high profit financially for both local industries and cement factory. The mechanical prope rties of bolt measured were tensile strength and hardness of bolt material. The microst ructure observed was form of grains especially on thread area of bolt. Results of inves tigation show that the average of material strength was 740 MPa. Form of grain in thread area was elongated, meanwhile the form of grains far from the thread of bolt was equiaxed. Al so, the hardness distribution in thread area was higher than that far from thread of bolt. It i ndicated that thread of bolt was formed by cold rolling process.