Q: I’m looking for a socket head cap screw that is 5/8″-11 x 5.5 inches in length. Need the material to be non-conductive and was thinking Ceramic Zirconia? Would that work?
A: Ceramics like Zirconia screws are in fact an excellent insulator from electrical current. However zirconia ceramic fasteners are very limited to smaller sizes between #2 – 1/4″ (M2-M6). Beyond this size they become very difficult to manufacture and are subject cracking. If electrical insulation is what you need, I would suggest a high performance polymer like PEEK socket head cap screws. PEEK is very economical compared to ceramics, an excellent electric insulator and can be made to just about any size. In addition, PEEK is tough, it will not be as fragile as a ceramic while offering the benefits of corrosion resistance and strength.