Hardness, or penetration, is a measurable characteristic that must be considered when selecting an appropriate grease. The hardness of the grease is determined by the number. No. 0 is the softest, and then increases to No. 6 along with No. 1 and No. 2. The hardness of No. 6 is the same as that of soap bars. The mud in the garden is easier to shovel and harder, and the hardness of the grease is the same. It is graded according to the penetration depth of the grease dropped from a certain height by the cone gauge. Printing machinery must be added with lubricating grease of appropriate hardness in accordance with the requirements of the printing press manufacturer, otherwise it may cause insufficient lubrication or increased resistance to the machine parts. Another feature of grease is the difficulty of pressure delivery; in the central grease supply system, two types of grease that are equally easy to pressure delivery at room temperature tend to have great pressure delivery performance in a lower temperature environment. different.