1.5” TC Bulkhead Compression Fittings are made of high quality SS304 and they are polished to perfection. Tri Clamp bulkhead allows you to add TC ports to any containers without welding, just drill a hole, and tighten the locknut with 2 high heat compatible silicone gaskets. The front of the flange does not have flats for a wrench. The easiest way to hold the flange for tightening is to clamp any other TC parts on with the gasket and clamp. Once tight, you can insert a long rod or screw driver into the hole of the wingnut. tri clamp bulkhead compression fittings are suitable for kettles, beer kegs, cola kegs, soda buckets with a diameter less than 12 inch.