Lubricants Used in Presses

In our previous blog post we discussed metalworking lubricants used for press metalforming, and in this post we will discuss "lubricants used in presses."

What are "lubricants"?

Lubricants provide the following beneficial effects.

・Friction Reduction: It forms an oil film that reduces friction.
・Wear Reduction: It prevents machine elements from coming into direct contact with each other, thereby reducing wear.
・Cooling: It absorbs friction-induced heat and prevents seizing.
・Sealing: The oil film prevents foreign matter from getting into the system.
・Rust Prevention: It adheres to metallic surfaces to prevent the formation of rust.

What kinds of lubricants are there?

There are a wide variety of lubricant types, each with different performance properties.
We will list some representative lubricant types here.

・Machine Oils: Generally used as a lubricant for bearings and in rotating friction areas in a wide variety of machines; it contains no additives of any kind.
・Gear Oils: Because these are used to protect gear tooth surfaces from wear, to reduce friction, and to protect against high-impact loads, these often contain extreme pressure additives.
・Spindle Oils: Primarily used in parts that rotate at high speed, such as light-load high-speed machines, small electric motors, and spinning machines; viscosities and loads are both low.
・Bearing Oils: Used to lubricate machine bearings that possess rust-prevention properties.
・Hydraulic Fluids: Used as the pressure medium in hydraulic equipment and as hydraulic oil in hydraulic pumps, etc; the viscosity is generally low.
・General-Purpose/Multi-Purpose Lubricants: Can be used for a wide array of applications, such as for bearings, gears, and hydraulic pressure; in many cases performance is boosted by additives.

What is the meaning of the designation such as "ISO VG 32" or "ISO VG 68" that is listed for a lubricant?

"ISO VG" is the viscosity grade defined by the International Standards Organization. The number following "ISO VG" is the median value of the lubricating oil's kinematic viscosity range at a temperature of 40°C. Viscosity units are expressed as "mm2/sec" or "cSt" (centistokes). The higher the viscosity value, the thicker and more viscous the oil will be; likewise, the smaller the value, the thinner and less viscous the oil will be.

Q1.  What types of lubricants should I choose for my press?

A1. Because presses are built using many different components such as bearings, guides, and gears, general-purpose/multi-purpose lubricating oils that possess an array of performance characteristics are often selected instead of specialized oils possessing one specific performance characteristic. At AIDA, we select the appropriate lubricant type and viscosity grade for each press model and for our peripheral equipment based on the specific application. And there have been cases in the past where a breakdown has occurred because even though a lubricant had the same viscosity grade as the AIDA-specified lubricant, the additives were different. A breakdown will not be covered by our warranty if it resulted from the usage of some lubricant other than the ones specified by AIDA, so we ask that you select from among the lubricants listed in the Instruction Manual for each lubricant type used in the various locations on the press.

Q2.  Is it necessary to replace lubricants with fresh lubricants? What would happen if I didn't ever replace the lubricants?

A2. Lubricants must be replaced on a regular basis because of the buildup of sludge from contaminants (such as foreign debris and metal wear particles) and because of water contamination, oxidative degradation, and additive performance degradation. Continuous use of a degraded lubricant can cause issues, such as the seizing of press bearings as well as press accuracy degradation due to an increase in the total clearance of the press.

In Closing...

In order for you to continue to use your press for a long time, we recommend that you use the lubricants specified in the instruction manual and that you replace them on a regular basis.