Selection criteria for lubricating oil for pneumatic punchs

As an indispensable key equipment in modern industrial production, the efficient and stable operation of pneumatic punchs directly affects production efficiency and product quality. The selection of lubricating oil is crucial in the maintenance and upkeep of pneumatic punchs. Appropriate lubricating oil can not only reduce equipment wear and prolong service life, but also improve the working performance of punching machines. This article will elaborate on the selection criteria for lubricating oil for pneumatic punchs, providing professional guidance for relevant enterprises and operators.

1、 Working characteristics and lubrication requirements of pneumatic punch

（1） High precision motion requirements
During the operation of pneumatic punchs, components such as sliders, guide rails, and connecting rods require high-precision reciprocating linear and rotational motion. This high-precision motion requires lubricating oil to form a uniform and stable oil film on the surface of the components to reduce friction and wear, ensuring the accuracy and stability of the motion. For example, during the stamping process, the gap between the slider and the guide rail is extremely small. If the lubricating oil cannot form an oil film in a timely and effective manner, it will cause direct contact between components, resulting in severe friction and wear, affecting the accuracy and service life of the punch press.
（2） High speed operation characteristics
Pneumatic punching machines usually have high operating speeds, and the reciprocating frequency of the slider may reach hundreds or even higher per minute. In high-speed operation, lubricating oil needs to have good fluidity and heat dissipation. Good fluidity can ensure that lubricating oil can quickly reach various lubrication parts and provide timely lubrication for components; Good heat dissipation can effectively remove the heat generated during the movement of components, preventing deformation or damage due to overheating.
（3） Complex force situations

During operation, various components of a pneumatic punch are subjected to various forces, including pressure, tension, shear force, etc. These complex stress conditions require lubricating oil to have high load-bearing capacity and anti-wear performance. Lubricating oil with strong load-bearing capacity can maintain the integrity of the oil film under high load conditions, preventing direct contact between components; Lubricating oil with good anti-wear performance can reduce surface wear of components and extend their service life.

2、 Core criteria for selecting lubricating oil for pneumatic punchs

（1） Viscosity grade
The Importance of Viscosity: Viscosity is one of the most important physical properties of lubricating oil, which directly affects the film-forming ability and flowability of lubricating oil on the surface of components. For pneumatic punchs, it is crucial to choose lubricating oil with the appropriate viscosity. If the viscosity of the lubricating oil is too high, it will cause a decrease in fluidity, making it difficult to quickly reach various lubrication parts, increasing the frictional resistance between components, and increasing the energy consumption of the equipment; At the same time, high viscosity lubricating oil may solidify in low temperature environments, causing equipment to fail to start properly. On the contrary, if the viscosity of the lubricating oil is too low, although it has good fluidity, it is difficult to form a sufficiently thick oil film on the surface of the components, which cannot effectively reduce friction and wear between components, especially under high load and high-speed operating conditions, which can easily lead to equipment damage.
Selection criteria for viscosity grade: When selecting the viscosity grade of lubricating oil for pneumatic punchs, it is necessary to comprehensively consider the operating temperature, operating speed, and load conditions of the equipment. Generally speaking, for pneumatic punchs working in high-temperature environments, lubricating oil with high viscosity should be selected to ensure the formation of a stable oil film at high temperatures; For equipment operating in low-temperature environments, lubricating oil with lower viscosity should be selected to ensure smooth start-up and operation at low temperatures. For high-speed pneumatic punchs, in order to reduce frictional resistance and energy loss, lubricating oil with lower viscosity should also be selected; But for high load pneumatic punchs, in order to ensure the load-bearing capacity of the oil film, it is necessary to choose lubricating oil with higher viscosity.
（2） Additive formula
Anti wear additives: Anti wear additives are one of the indispensable components in the lubricating oil of pneumatic punchs. It can form a chemical film with anti-wear properties on the surface of components. When the contact pressure between components exceeds the load-bearing capacity of the oil film, this chemical film can prevent direct contact between components and reduce wear. Common anti-wear additives include sulfur phosphorus type, sulfur phosphorus nitrogen type, etc. For example, in heavy-duty pneumatic punchs, adding an appropriate amount of anti-wear additives can effectively reduce the wear rate of components and extend the service life of the equipment.
Extreme pressure additives: Extreme pressure additives are mainly used to enhance the load-bearing capacity of lubricating oil under extreme working conditions such as high temperature, high pressure, and high speed. When the equipment is under extreme pressure conditions, the extreme pressure additive will undergo a chemical reaction with the surface of the components, generating a low melting point chemical reaction film. This film can prevent welding and biting between components under extremely high pressure. For example, in high-speed pneumatic punchs, extreme pressure additives can ensure the normal operation of equipment under high-speed and high load conditions, avoiding equipment failures caused by extreme pressure wear.
Antioxidant additive: During the operation of pneumatic punchs, lubricating oil will come into contact with oxygen in the air, which is prone to oxidation reactions, generating acidic substances and precipitates. These oxidation products will reduce the performance of lubricating oil, corrode equipment components, and shorten the service life of equipment. Antioxidant additives can inhibit the oxidation reaction of lubricating oil and prolong its service life. For example, phenolic and amine based antioxidant additives can effectively capture free radicals, prevent oxidation chain reactions, and protect lubricating oil from oxidative damage.
Rust and anti-corrosion additives: The components of pneumatic punchs are mostly made of metal materials, which are prone to rust and corrosion in humid environments. Rust and anti-corrosion additives can form a protective film on the metal surface, preventing moisture and oxygen from coming into contact with the metal, thereby preventing rusting and corrosion of the metal. For example, rust and anti-corrosion additives such as sulfonic acid salts and carboxylic acids can adsorb onto metal surfaces, forming a dense protective film that effectively protects equipment components from corrosion.
（3） Quality level
Classification criteria for quality levels: The quality level of lubricating oil is usually classified based on its performance indicators and usage requirements. The commonly used quality grading standards for lubricants internationally include the American Petroleum Institute (API) standards, the International Organization for Standardization (ISO) standards, and so on. These standards strictly regulate multiple indicators of lubricating oil, such as viscosity, flash point, pour point, anti-wear performance, and anti-oxidation performance. For example, API standards classify engine lubricants into multiple grades such as SA, SB, SC, SD, SE, SF, SG, SH, SJ, SL, SM, SN, etc. The higher the grade, the better the performance of the lubricant. For the lubricating oil of pneumatic punchs, there are corresponding quality grade standards, and enterprises should choose the appropriate quality grade lubricating oil according to the specific requirements of the equipment.

The significance of choosing high-quality grade lubricating oil: Choosing high-quality grade pneumatic punch lubricating oil can ensure better protection of equipment. High quality lubricating oil usually has better anti-wear performance, anti-oxidation performance, rust and anti-corrosion performance, etc., which can provide reliable lubrication guarantee for equipment under more harsh working conditions. For example, using API SH and above grade lubricants can significantly reduce the wear rate of pneumatic punchs, extend the service life of equipment, and reduce the frequency and cost of equipment maintenance.

3、 Other considerations

（1） Compatibility with sealing materials
A large amount of sealing materials are used in pneumatic punchs, such as rubber sealing rings, gaskets, etc. Poor compatibility between lubricating oil and sealing materials can cause the sealing material to expand, contract, harden, or dissolve, thereby affecting the sealing effect and causing lubricating oil leakage. Therefore, when selecting lubricating oil, it is necessary to consider its compatibility with equipment sealing materials. Generally speaking, lubricant manufacturers will indicate the type of sealing material applicable to the lubricant in the product manual. Users should carefully read the manual when selecting to ensure that the selected lubricant is compatible with the equipment sealing material.
（2） Environmental requirements
With the continuous improvement of environmental awareness, the environmental requirements for lubricants are also increasing. When choosing lubricating oil for pneumatic punchs, environmentally friendly lubricating oil such as biodegradable lubricating oil should be selected as much as possible. Biodegradable lubricants have good biodegradability and cause minimal environmental pollution during use. At the same time, environmentally friendly lubricants should also comply with relevant environmental regulations and standards, such as low volatile organic compound (VOC) content and no heavy metal pollution.
（3） Supplier's technical support and services
Choosing a lubricant supplier with good technical support and service is also very important. Suppliers should be able to provide professional lubricant selection recommendations and recommend suitable lubricant products to users based on the specific working conditions and requirements of pneumatic punchs. At the same time, suppliers should also provide timely after-sales service, including lubricant testing, replacement guidance, etc., to help users solve problems encountered during use.
The selection of lubricating oil for pneumatic punchs is a comprehensive process that requires consideration of multiple factors such as the working characteristics of the equipment, lubrication requirements, viscosity grade, additive formula, quality grade, compatibility with sealing materials, environmental requirements, and technical support from suppliers. Only by selecting the appropriate lubricating oil can the efficient and stable operation of pneumatic punchs be ensured, the service life of equipment be extended, production costs be reduced, and the economic benefits of enterprises be improved. Therefore, relevant enterprises and operators should attach great importance to the selection of lubricating oil for pneumatic punchs, and strictly follow the selection criteria for selection and use.