Coolants for Heavy Duty Machining

This is a copy of the post created by Monroe Fluid Technology, June 2021. Used with permission.

Written by Fred Kane, Monroe Fluid Technology

Monroe Fluid Technology has two ‘workhorse’ water soluble oil concentrates, designed specifically for the demands of heavy duty machining applications. Where a chlorinated additive is specified, our Astro- Sol C HD is recommended. In circumstances where a chlorinated additive may not be suitable, we offer Astro-Sol A-XBP. Both are low foaming products, suitable for virtually all metals and applications, and are designed to resist bio-degradation.

Astro-Sol A-XBP

Astro-Sol A-XBP is a medium-to-heavy duty biostatic soluble oil. This product was designed to be extended with water for the machining and grinding of virtually all metals except magnesium. This chlorine-free formulation is especially suited for aerospace and other applications which restrict the use of chlorine. Astro-Sol A-XBP has exceptional foam control for high-pressure operations and was designed using raw materials that have the ability to resist extreme biological degradation, thus providing a very long sump life in a properly maintained machine tool. Astro-Sol A-XBP is designed for use in metalworking applications such as all CNC milling, turning, drilling, tapping, grinding and sawing applications.

Astro-Sol C HD

Astro-Sol C HD is an extreme duty soluble oil concentrate designed for the most demanding machining operations where controlled foam and cleanliness are required. The unique combination of chlorinated extreme pressure additive, modern boundary lubricants, and a controlled-foam emulsifier package brings outstanding performance to the most severe applications. Astro-Sol C HD is formulated with a high level of stabilized chlorinated EP additive using a synthetic emulsification platform that is very stable and exceptionally low foaming. Astro-Sol C HD is designed for use in heavy-duty metal removal, deep hole drilling, tapping and threading, as well as all conventional machining and is very effective in sawing operations.

Trial Monroe Metalworking Fluids

If you have an interest in trialing one or both of these products, just inquire and we will send samples and also our Astro-Clean A, a sump cleaner you can add directly on top of your current coolant, run for 24-48 hours while making parts, then dump, rinse and recharge with the new coolant. Remember, water quality is important, so we may need a sample of your water for testing, or if you know the hardness of your water, we can resolve that issue easily.

Twin Specialties is an authorized distributor for Monroe Fluid coolants, oils, rust preventatives, and industrial cleaners. Contact Twin Specialties to learn more about Monroe Fluid’s product line and learn about our sampling and testing programs. Check out Twin Specialties’ catalog of metalworking fluids, rust preventatives, and industrial cleaners.

3 Factors for Perfecting Aqueous Cleaning

When cleaning finished machine parts, manufacturers have to meet the increasingly stringent cleanliness tolerances, while also operating a cost-effective cleaning process. Old standards no longer apply and manufacturers have to evaluate their operations to select the best cleaning process. Just utilizing best practices and monitoring your tank is not enough.

The first thing that should be assessed is the contamination generated in all stages of the manufacturing process. Engineers should have data on all processes and substances that parts have been exposed to. Cleaner and equipment suppliers should have reliable lab work to help understand the process and contaminants. Equipment and cleaner manufacturers should provide transparent testing and results to demonstrate the value and effectiveness of their solution.

The 3 Cleaning Energies

Every cleaning process will depend on a balance of 3 energies: chemical, thermal, and mechanical. If one form of energy is increased, the other two forms of energy can typically be reduced. The key to perfecting your aqueous cleaning process will be balancing the 3 energies.

Chemical Energy

Chemistry should be the first consideration in developing a cleaning process. The part material and contamination will determine the appropriate pH range of your aqueous cleaner. The goal is to minimize chemistry at the lowest temperatures and least costly form of mechanical energy to achieve cleanliness standards in the required time cycle.

Alkaline cleaners (pH 9-14) are ideal for removing organic contaminants such as oils, greases, coolants, etc. Acidic cleaners (pH 1-6) are ideal for removing inorganic contaminants such as oxides and rust. Neutral cleaners are excellent for use in systems that use more mechanical energy such as ultrasonic cleaning.

Depending on the part material, less or more aggressive cleaners will be appropriate. More neutral chemistries should be considered for softer and more reactive metals, such as aluminum, copper, or brass. A more aggressive chemistry could start attacking/reacting with the part itself. Less reactive metals can withstand stronger chemistries, higher temperatures, and more mechanical energy. Inert chemistries will require more mechanical energy to drive reactions and break down contaminants.

Thermal Energy

Heat is controlled in a cleaning system by different heating elements. What elements and how they are programmed are dependent on your goals and system. It is important to carefully monitor temperatures to prevent reduced heat element life and temperature capacity. Sensors and controllers are recommended to monitor cleaning systems and can help prolong service life and improve performance.

Heat increases the speed of molecules and faster molecules are better at breaking down bonds of contaminants. For every 17 F increase in temperature, reaction rates can double. This can accelerate the cleaning process. The optimal temperature in most systems is 120 F to 160 F. Too low of temperatures can lead to foaming and less effective cleaning.

Increased heat can reduce drying times and accelerate the cleaning process. It is important to remove pools of water using gravity or airflow. However, too hot of temperatures could create “flash rusting,” which can lead to parts being deemed off-spec or require additional cleaning or work.

Mechanical Energy

The final piece of the puzzle is mechanical energy. This is determined by the equipment and process that is used. Vertical agitators are popular because of their forgiveness and ability to avoid oil loading. The main way to generate mechanical energy is creating agitation.

In immersion cleaning systems, agitation is created by moving the parts in and out or within a tank of cleaner. Spray washers introduce agitation by introducing energy into the cleaner by spraying it at high speeds onto parts. Spray washers can be used in conveyer systems that have multiple stages, such as washing, rinsing, and rust inhibiting.

Ultrasonic cleaning introduce the most mechanical energy and are ideal for cleaning processes with limited heat and less aggressive chemistry. Ultrasonic cleaning should be considered when conventional methods fail to meet cleanliness tolerances.


Balancing the three energies is key to perfecting a cleaning process. When selecting an aqueous cleaner, consider your equipment, process, contaminants, and part material. Twin Specialties offers a full-line of aqueous cleaners that can fit any cleaning process. Many cleaners are specifically designed for ultrasonic, spray, and/or immersion cleaning process. Contact Twin Specialties to learn more about our aqueous cleaners and see what product is right for you.