Stainless Steel Corner Brackets Set Fixing Mending Brace Plates with Fixing Screws Straight Corner Brace Stainless Steel Flat Straight Brace Brackets Shelf Support Fastener with Screws

Question:What type of metal? Aluminum? Steel? Answer:These are made of steel. Question:Will a magnet stick to these? Answer:They are Non Ferrous so NO a magnet will not be attracted to these. Question:How long are the screws? Answer:Package come with the srews, screw length is 16mm.But it would be hard for us to know the length of the screw your particular project would require, you can substitute other suitable screws by yourself if you think you need it. Question:are the screws stainless steel as well? Answer:Yes, it contains 90 M4*16MM stainless steel screws. Question:can these withstand the heat of a fireplace? Answer:It's stainless steel.Yes, I think they can.But metal conducts heat. Be careful not to burn. BUYER README I started to hang a very large wall mirror. 3 screws on both side options are very helpful. I used 3 on wall and 2 screws in mirror. I drilled mirror frame to to avoid damage to the frame slowly. These were perfect for what I was looking to do. Gave my project a very professional finished look.