The Smith & Wesson handcuffs are made of carbon steel.  Handcuffs meet U. S. National Institute of Justice tests for workmanship, strength, corrosion, and tamper resistance.
 
Police Issue Carbon Steel With Nickle Finish Smith And Wesson Handcuffs
Passes All NILEC And NIJ Specifications
Double Lock Slot Both Sides
Wrist Opening: 2.04" Irst Notch Inside Perimeter: 8.4" Last Notch Inside Perimeter: 5.8" Tightest Inside Width: 1.8" Distance Between Cuffs: 2" Maximum Overall Length: 8.98"
Uses Standard Key