Locks FS 156 are premium tapping oil of a supper heavy-duty formulations. These high viscosity mineral tapping oils are fortified with large quantity of high quality of active and non active-sulfur and new type of phosphorus EP additive. Locks FS 156 are made to perform very high surface finishing and excellent tools protecting. Special heat resistant agent further imparts the anti-heat property. Locks FS 156 are special used in precision tapping of metal parts of very tough metal such as stainless steel and heat resisting steels.