Sealcon NM-16-SS high quality stainless steel locking nuts are liquid tight to 150 psi. M16 x 1.5 Metric Thread. Sold Individually. Made from 303 stainless steel. Sealcon M16 x 1.5 Stainless Steel Locking Nuts can provide a NEMA 4x & 6 (IP 68 & 69K), 150 PSIG (10 bar) Liquid Tight Rating. They are ideal in chemical plants, off shore rigs, marine applications and food processing.