https://www.intel.com/content/www/us/en/content-details/811905/sr4850hw4m-shw4urm3sa-sr6850hw4m-and-shw6urm3sa-pcn-107878-00-product-design-class-2-accessories-ahwprochs-improved-screw-usability-on-heatsink.html
SR4850HW4M,SHW4URM3SA,SR6850HW4M and SHW6URM3SA, PCN 107878-00, Product Design, CLASS 2:...
Server Boards and Platforms, Product Design, Intel anticipates no impact to customers, see PCN detail for further information.