Easy to tighten  Fastener Expertise Q & A    Issue 28 The bearing surface that is contacted by the coupling member and the nut or bolt head should be flat, for ______. A. Beautiful appearance B. Easy to install and disassemble Last review--When the 27th joint is subjected to lateral external force, if the bolt is used, the possible failure form of the bolt is ______. A. shear or crush damage B. pull off Answer analysis: D All-In-One Kitchen Sink,All In One Sink,All In One Undermount Kitchen Sink,All In One Stainless Steel Kitchen Sink Zhongshanshi JiaBaoLu Kitchen And Bathroom Products Co., Ltd , https://www.gabalusink.com
C. Avoid weakening the bolt strength D. Prevent the contact surface of the nut or bolt head from being scratched 
C. Breaking under the combined action of pulling and twisting D. Plastic deformation under the combined action of pulling and twisting 