In order to investigate the effect of cutting fluids on reaming operation, reaming tests were performed with various kinds of cutting fluids, and reaming torque and accuracy of reamed holes were compared for dry and wet cuttings. Tests were also made dry and wet for different cutting conditions, and effects of conditions on reaming torque and accuracy of reamed holes were investigated. Application of cutting fluids improved the accuracy of reamed holes, though reaming torque was increased. The cutting torque component was scarcely affected by cutting fluids. But cutting fluids increased the burnishing torque component in the order of dry, cutting oils, and soluble oils. Dry reaming and reaming with cutting oils produced oversized holes. Reaming with soluble oils produced smaller holes than the actual size of the reamer. The smaller the amount of enlargement of the reamed hole, the larger the burnishing torque component, and the better the surface finish in the order of dry, cutting oils, and soluble oils. With increases in cutting speed, feed, and depth of cut, the amount of enlargement increased and the surface finish of the reamed hole became worse for both dry and wet conditions. The sharp reamer showed a peculiar phenomenon for torque pattern in relation to feed rate. The stable reamer which was used several dozen times produced better reamed holes than the sharp reamer
