"NSN USED TO PURCHASE A MINIMUM OF 16CONTAINRS TO A MAXIMUM OF 39CONTAINERS;CERTIFICATION GE A50TF87 CLASS A,PWA 1311 AND RR 9507/36;RC 50-60 HARDNESS;5000 PSI MINIMUM STRENGTH;GRIND ONLY.USE SILICON CARBIDE OR DIAMOND WHEELS;GREY ALUMINA POWDER 2.5% TITANIUM DIOXIDE W/SMALLER %(S) OF OTHER OXIDES USED TO TOUGHEN GRAIN.COATINGS ARE HARD, DENSE AND RESISTANT TO BOTH HEAT AND WEAR.RECOMMENDED FOR RESISTANCE TO CAVITATION AND ABRASION"