Threaded prezons (hanger bolts) for anchoring metal collars with or without gasket that fix and protect metal or plastic pipes used in HVAC systems, water-sewage or related areas. What are ...Walraven bearings? Walraven bolts are part of the range of so-called captive screws or eccentric screws with two threading ends (threading or fixing in the wall or ceiling and threading for joining with the metal collar for fixing pipes: https://www.youtube.com/ watch?v=pC-Whl5oxuc These threaded bolts have lengths that vary between 50 mm and 200 mm, being part of the Torx range of threaded hole screws, which are fixed with a professional drill. Mai mult