No, there was no fastening material included.
Since every board manufacturer comes up with its own fastening variant, that would make no sense.
I've already had M3 screws, clips and something like a "wheel screw" for fastening.

unfortunately not

Samsung Electronics Co., Ltd.
Hello,
thank you for your enquiry.
There are no screws included with the Samsung 980 PCIe® 3.0 NVMe™ M.2 SSD - 1 TB MZ-V8V1T0BW. You have the option of using the screws that may be included with your laptop's mainboard. If this is not the case, they must be purchased separately. Please refer to the operating instructions of your mainboard for the required screw size or contact your device manufacturer directly.
Kind regards from Schwalbach
Your Samsung Service Team

For mounting in the slot.Yes