Plastic Weld or Plastic Welder (two brands; we use both) are two part methylmethacrylate adhesives strongly resistant to mechanical shock - hammer blows for instance - three times stronger than the best commercial two part epoxies, and 50% stronger than any commercial cyanoacrylate adhesive.
One cartridge will glue 4 mounting plates.
Methylmethacrylate has a "best before" shelf life of 9 months. We suggest you order no more than your forseeable requirements.