AquaTec 7655 Coolant

March 09, 2020
AquaTec 7655 Coolant

oelheld has been on the forefront of lubricant innovations for over 130 years. The company's R&D team in cooperation with machine manufacturers, universities and customers know exactly what to expect from water-miscible coolants and their challenges. Water-miscible coolants have many advantages over their straight oil counterparts, but they also have some well-known disadvantages such as corrosion (machines and parts), lubricity (tool life) and sump life (fungi, bacteria).

This has been the motivation for the R&D department to break new ground and develop new products that guarantee that most of these disadvantages are a thing of the past. These expectations, special requirements and problems have been taken care of as a result of this extensive R&D work, which resulted in the development of the AquaTec 7655 coolant.

The AquaTec 7655 is suitable for high-pressure applications or processing nonferrous metals. During the development of the AquaTec 7655, special attention was paid to process stability and the reduction of maintenance costs, as this offers an enormous competitive advantage for our customers when working at high capacity. The use of modern raw materials and therefore the compliance with the latest chemical laws, make the AquaTec 7655 a long-term choice.

With the new AquaTec 7655, the company took on these challenges and will improve your manufacturing process, as well as reducing your ongoing costs at the same time. By choosing the right coolant, you not only save time and money, but you eliminate your other concerns so you can focus on manufacturing.

Health benefits:
AquaTec 7655 produces low emissions
 AquaTec 7655 meets the requirements of REACH
AquaTec 7655 has very good long-term stability
AquaTec 7655 is free from heavy metals and organochlorine compounds

AquaTec 7655 is an EP cooling lubricant concentrate containing mineral oil, which is suitable for almost all types of metalworking. Long tool life is achieved by special EP additives. The concentrate was developed to produce the highest surface qualities and is particularly low in foam and odor.
High surface quality of workpieces
Particularly low-foaming
Can be used with both high and low water hardness
Low maintenance and care requirements, saving you time
Contains no organochlorine compounds
High emulsion stability
Long tool life
Extremely high stability even without the use of additives
Excellent machine cleaning effect
Low air pollution for a better environment
No corrosion problems

Application concentration:
Machining of aluminum alloys 8 – 10 %
Heavy machining 8 – 20 %

Technical facts:
Color of the concentrate is brown)
Mineral oil content is approx. 45 %
pH-value of a 5% emulsion is 9.2
pH-value of the concentrate is 9.8
Corrosion protection 6% (Grade 0; testing method: DIN 51 360 T2)

Always put the concentrate into the water, not the other way round, otherwise no stable emulsion is formed. Since AquaTec 7655 is a high concentrate cooling lubricant, it is imperative to follow the correct sequence. The water hardness should not be lower than 4°dH and should not exceed 25° dH. A water hardness between 6° dH and 16° dH is ideal. Please do not use hot/warm water to prepare the emulsion.

AquaTec 7655 should be able to be mixed with most other cooling lubricants. In individual cases; however, it is advisable to contact the oelheld laboratory, which has tested a large number of competitor products for their miscibility.

AquaTec 7655 is suitable for processing all ferrous and nonferrous metals. It is not suitable for machining magnesium. When machining copper, a slight discoloration of the cooling lubricant may occur, but no discoloration of the workpiece. However, leaving copper/brass parts in the cooling lubricant for a longer period of time should be avoided. Cast iron can also be processed continually without any problems, e.g. EN-GJS-600-3 or EN-GJS-600-7. When machining aluminum, as well as steel, the tool life can be doubled by changing to AquaTec 7655.

AquaTec 7655 should be used with at least 7% in the machine. Your tools will thank you for it. Field reports of a customer turning V4A material: at 6% concentration the insert has to be replaced after 11 parts. After increasing the concentration to 10%, 25 parts could be machined with one insert. With the heaviest machining, where chlorine containing special greases were previously used, a concentration of 14% meant that additional manual greasing of the parts was not required at all.

Experience has shown that AquaTec 7655 is very stable and requires little maintenance. It is important not to let the concentration drop below 7%. In most machines, the cooling lubricant has not required changing since the switch was made to AquaTec 7655, in some cases for more than 4 years.

A dermatological expert opinion attests AquaTec 7655 to have a good skin compatibility. However, due to the alkalinity (pH value 8.8 to 9.2) you may consider skin protection on a case-by-case basis. This applies to all water-mixed cooling lubricants.

AquaTec 7655 is very low foaming. Flushing pressures of up to 80 bar with internally cooled tools are possible without problems (higher pressures are not usual in the industry).

The cooling lubricant must be monitored in accordance with TRGS 611 regulations and the application concentration should be checked using a hand refractometer.

Related Glossary Terms

  • alloys


    Substances having metallic properties and being composed of two or more chemical elements of which at least one is a metal.

  • aluminum alloys

    aluminum alloys

    Aluminum containing specified quantities of alloying elements added to obtain the necessary mechanical and physical properties. Aluminum alloys are divided into two categories: wrought compositions and casting compositions. Some compositions may contain up to 10 alloying elements, but only one or two are the main alloying elements, such as copper, manganese, silicon, magnesium, zinc or tin.

  • coolant


    Fluid that reduces temperature buildup at the tool/workpiece interface during machining. Normally takes the form of a liquid such as soluble or chemical mixtures (semisynthetic, synthetic) but can be pressurized air or other gas. Because of water’s ability to absorb great quantities of heat, it is widely used as a coolant and vehicle for various cutting compounds, with the water-to-compound ratio varying with the machining task. See cutting fluid; semisynthetic cutting fluid; soluble-oil cutting fluid; synthetic cutting fluid.

  • emulsion


    Suspension of one liquid in another, such as oil in water.

  • extreme pressure additives ( EP)

    extreme pressure additives ( EP)

    Cutting-fluid additives (chlorine, sulfur or phosphorus compounds) that chemically react with the workpiece material to minimize chipwelding. Good for high-speed machining. See cutting fluid.

  • hardness


    Hardness is a measure of the resistance of a material to surface indentation or abrasion. There is no absolute scale for hardness. In order to express hardness quantitatively, each type of test has its own scale, which defines hardness. Indentation hardness obtained through static methods is measured by Brinell, Rockwell, Vickers and Knoop tests. Hardness without indentation is measured by a dynamic method, known as the Scleroscope test.

  • lubricity


    Measure of the relative efficiency with which a cutting fluid or lubricant reduces friction between surfaces.

  • metalworking


    Any manufacturing process in which metal is processed or machined such that the workpiece is given a new shape. Broadly defined, the term includes processes such as design and layout, heat-treating, material handling and inspection.

  • miscibility


    Ability of a liquid to mix with another liquid. See emulsion.

  • refractometer


    Optical instrument that measures the refractive index of a liquid, such as a water-diluted metalworking fluid mix. The refractive index can by used to determine the concentration of a fresh metalworking fluid mix.

  • straight oil

    straight oil

    Cutting fluid that contains no water. Produced from mineral, vegetable, marine or petroleum oils, or combinations of these oils.

  • turning


    Workpiece is held in a chuck, mounted on a face plate or secured between centers and rotated while a cutting tool, normally a single-point tool, is fed into it along its periphery or across its end or face. Takes the form of straight turning (cutting along the periphery of the workpiece); taper turning (creating a taper); step turning (turning different-size diameters on the same work); chamfering (beveling an edge or shoulder); facing (cutting on an end); turning threads (usually external but can be internal); roughing (high-volume metal removal); and finishing (final light cuts). Performed on lathes, turning centers, chucking machines, automatic screw machines and similar machines.