That tonearm looks like its made of "Alumaclad" which is used for decorative cladding of exterior mainly commercial buildings,its very thin 1mm aluminum top and bottom and 2mm black plastic in the middle,it can be made to bend around corners if you router a "V" groove on the reverse side,and will bend at the groove leaving a nice crisp corner,I had used a scrap piece as a top plate for one of my DIY tube amp builds,easy to cut but no compression strength,so if you screw a screw in to it to much it will compress,I would imagine that tone arm being narrow would bend.