Charudatta Bandgar
Forum Moderator
Hello JUGYEONG SHIN Please go through the video explanation in this query (first comment, attachment titled Bolt_preload). Bolt preload on cylindrical face is not possible if you are working in explore mode, although you can use assign tool to create a 1D beam element, and apply preload to that.  You can apply bolt preload on the cylindrical face, if you are working in the refine mode. Regards.