A Study on Characteristics of Magnitude and Distribution Area for Contact Pressure Relative to Separated Distance from Middle of Two Bolts by Tightening Distance Between Flange Bolts

In this study, as a second step, the characteristics of magnitude and distribution area for contact pressure with respect to the separated distance from bolt center were investigated by the tightening distance between two bolts for each flange bolt size. The sizes of flange bolt were M6, M8, M10 and M12. The tightening torque for the size of each flange bolt was applied by the minimum value. The results show that the slope of contact pressure magnitude according to the separated distance from the middle of the two bolts was almost the same even if the tightening distance between the flange bolts was increased, and as the flange bolt size was increased, the tightening distance between bolts at the minimum setting contact pressure of 1 MPa was increased. It is found, in addition, that the larger the flange bolt size for the same contact pressure in the contact pressure distribution area of 1 to 3 MPa, the greater the distribution area of contact pressure because the separated distance from bolt center in the two cases than the one flange bolt tightening was increased. This tendency was more greatly shown as the flange bolt size was larger and the contact pressure was closer to 1 MPa.