FUCHS RENEP CGLP 68T | ISO VG 68 Machine Tool Slideway Oil

Product Description

FUCHS RENEP CGLP 68T is a premium ISO VG 68 slideway oil developed for the precise lubrication of machine tool slideways, linear guides and associated lubricating systems. It is formulated to produce a stable, adhesive lubricating film with a low coefficient of friction, helping machine tools move smoothly and accurately during start-up, micro-feed movements and high-load positioning operations.

The quality and dimensional accuracy of a machined component depend heavily on the controlled movement of the machine tool. Conventional lubricants may not provide the friction characteristics, adhesion or cutting-fluid compatibility required by modern slideways. RENEP CGLP 68T uses carefully selected base oils and a matched additive system to reduce friction, resist stick-slip and protect sliding surfaces against wear, seizure and corrosion.

Stick-slip occurs when the difference between static and dynamic friction causes a slideway to alternate between sticking and moving. This irregular movement can produce chatter, ripples, poor surface finish and inaccurate positioning. The friction-modifying components in FUCHS RENEP CGLP 68T help maintain smoother movement at low feed rates and under high loads, supporting greater machining accuracy and consistent finished-component quality.

The formulation also provides good extreme-pressure and anti-wear performance. Chemically active protective agents help reduce micro-welding, scoring and seizure when the lubricating film becomes very thin or the slideway is temporarily exposed to severe boundary-lubrication conditions. These properties support dependable machine operation, reduced wear and longer service life for valuable machine-tool components.

RENEP CGLP 68T is particularly suitable for machine tools using water-miscible metalworking fluids. Its strong demulsifying performance promotes separation between the slideway oil and cutting fluid, helping reduce the formation of stable emulsions, sticky deposits and lacquer-like residues. This compatibility supports cleaner lubrication systems, more consistent friction performance and easier management of contaminated cutting fluids.

Specifications and Approvals

• Brand: FUCHS
• Product: RENEP CGLP 68T
• Product type: High-performance machine tool slideway oil
• Viscosity classification: ISO VG 68
• Product code: 2557
• Primary application: Machine tool slideways and linear guides
• Formulation: Refined base oil and performance additives
• Hydraulic application: May also perform the function of an HLP 68 hydraulic oil where approved by the machine manufacturer
• Approved by: Dörries Scharmann Technologie GmbH
• Approved by: Hegenscheidt MFD
• Australian dangerous-goods classification: Not classified as Dangerous Goods for road or rail transport
• Australian workplace classification: Not classified as hazardous according to Safe Work Australia GHS 7 criteria, based on the applicable Australian Safety Data Sheet

The product information sheet does not list a separate formal specification under its “Specifications” heading. Equipment compatibility should therefore be confirmed using the stated viscosity, performance characteristics, manufacturer approvals and the lubricant requirements specified in the machine operating manual.

Recommended Applications

FUCHS RENEP CGLP 68T is recommended for the lubrication of:

• Horizontal machine tool slideways
• Vertical machine tool slideways where ISO VG 68 is specified
• CNC machining centre guideways
• Milling-machine tables and slideways
• Grinding-machine slideways
• Lathes and turning centres
• Planers and shaping machines
• Boring machines
• Precision positioning systems
• Linear guides and linear guide systems
• Cast iron-to-cast iron sliding surfaces
• Steel-to-cast iron slideways
• Steel-to-plastic slideway combinations
• Centralised machine tool lubrication systems
• Hydraulic systems requiring HLP 68 performance where specifically accepted by the equipment manufacturer

The correct slideway lubricant should be selected according to the machine design, slideway materials, lubrication-groove geometry, operating load, feed speed, cutting fluid and manufacturer instructions. Although RENEP CGLP 68T can provide both slideway lubrication and hydraulic functionality in suitable equipment, it should not be substituted automatically for every ISO VG 68 hydraulic oil.

Key Features and Benefits

Stable, Adhesive Lubricating Film

Polar, surface-active substances within the formulation help the oil attach to lubricated surfaces and maintain a stable film between moving slideway components. This adhesion is especially important during slow feed movements, intermittent operation and start-up conditions, when a conventional circulating oil may drain away or fail to provide sufficiently controlled friction.

A persistent lubricating film helps prevent direct contact between sliding components and supports smoother, more predictable machine movements.

Low Coefficient of Friction

FUCHS RENEP CGLP 68T is formulated to reduce friction at machine tool lubrication points. Its low-friction characteristics can decrease the resistance encountered by slideway drive systems during start-up and feed movements.

Lower sliding resistance can support reduced initial current demand from the machine’s drive motors. More importantly, it helps enable accurate positioning and controlled feed rates during precision machining.

Effective Stick-Slip Control

Stick-slip can occur at very low speeds or under heavy loads when the slideway initially resists movement and then moves suddenly. This inconsistent motion may affect dimensional accuracy, produce surface ripples and create chatter marks on machined components.

RENEP CGLP 68T helps minimise the difference between static and dynamic friction. The result is smoother slideway travel, more uniform feed and improved control during precision or micro-feed machining operations.

Extreme-Pressure and Anti-Wear Protection

The additive system provides good extreme-pressure and anti-wear performance under demanding boundary-lubrication conditions. Protective chemical layers can continue to defend metal surfaces when the oil film becomes exceptionally thin.

This protection helps reduce scoring, micro-welding, wear and seizure on heavily loaded slideways. It also provides an added level of operational reliability if lubricant delivery is briefly reduced or interrupted.

Protection for Steel and Non-Ferrous Metals

RENEP CGLP 68T provides corrosion protection for steel and non-ferrous metal components. This is particularly valuable in machine tool environments where slideways may be exposed to water-miscible cutting fluids, humidity and machining contamination.

The corrosion-control additives help protect exposed metal surfaces and reduce the possibility of staining or black discolouration associated with unsuitable combinations of slideway lubricant and metalworking fluid.

Strong Demulsifying Performance

Slideway oil inevitably comes into contact with cutting fluid in many machine tools. If the two products form a stable emulsion, the slideway oil may be washed away from the lubricating surface. The mixture may also increase friction, affect cutting-fluid stability and contribute to deposits or lacquer formation.

FUCHS RENEP CGLP 68T is designed to separate efficiently from compatible water-miscible cutting fluids. Its demulsifying characteristics support distinct oil and cutting-fluid phases, allowing unwanted slideway oil to be removed more readily from the cutting-fluid system.

Compatibility with FUCHS Cutting Fluids

FUCHS states that its RENEP CGLP slideway oils are compatible with FUCHS cutting fluids. This makes RENEP CGLP 68T a strong choice for facilities already using FUCHS water-miscible metalworking products.

Good chemical compatibility helps minimise adverse interactions that could otherwise affect cutting-fluid cleanliness, foaming, filtration, residue formation or lubricating performance. Compatibility with other cutting fluids should be assessed according to the operating concentration and machine conditions.

Oxidation Stability

Oxidation inhibitors help protect the oil against premature ageing during service. Resistance to oxidation can reduce the formation of acidic degradation products, sludge and deposits, supporting longer lubricant life and cleaner lubrication systems.

The product information reports an oxidation stability result of less than 2 mg KOH/g change after 1,000 hours under ASTM D943 test conditions.

Good Load-Carrying Capacity

RENEP CGLP 68T achieves FZG failure load stage 12 under the stated mechanical gear test and a 60 lb Timken OK load. These results demonstrate the lubricant’s capacity to protect loaded surfaces under demanding test conditions.

Although these results support the product’s anti-wear and extreme-pressure performance, the oil should still be used only in applications for which its viscosity and operating characteristics are appropriate.

Machine Tool Performance

Accurate feed and positioning are fundamental to machining quality. During start-up, the lubricant must allow the slideway to begin moving without an excessive breakaway force. During low-speed feed, it must maintain consistent movement without alternating between static and dynamic friction.

RENEP CGLP 68T was developed to address these conditions. In the SKC-Technik inclined tribometer test, the product recorded a coefficient of friction of 0.085. Its friction characteristics help support smooth movement even at low feeds and high loads.

The lubricant is suitable for traditional slideway material combinations, including cast iron-to-cast iron, steel-to-cast iron and steel-to-plastic arrangements. It is also recommended for appropriate linear-guide systems used in modern machine tools.

Lubrication frequency and delivery volume must be matched to the machine design and operating cycle. Excessive lubrication may increase oil carryover into the cutting-fluid system, while inadequate lubrication can contribute to wear, chatter, corrosion or seizure.

Cutting-Fluid Separation and Cleanliness

When slideway oil enters a water-miscible cutting-fluid system, rapid separation is desirable. A poorly separating oil may remain dispersed through the cutting fluid, increasing contamination and potentially affecting filtration, biological stability and machining performance.

FUCHS RENEP CGLP 68T has a stated demulsibility result of 10 minutes under DIN 51599. Its separation characteristics help the slideway lubricant release from the water-based fluid rather than forming a persistent emulsion.

This can assist operators in removing tramp oil using skimmers, separators or routine sump-maintenance equipment. Effective tramp-oil control can contribute to cleaner cutting fluid, improved workplace conditions and more reliable metalworking-fluid performance.

Typical Physical Properties

Handling & Storage Advice

Store FUCHS RENEP CGLP 68T in its original, correctly labelled container in a cool, dry and well-ventilated area. Keep it protected from direct sunlight, elevated temperatures, ignition sources, foodstuffs and incompatible materials such as strong oxidising agents.

Keep containers securely closed when not in use and store them upright. Check drums, pails and dispensing containers regularly for leakage, damage or contamination. Water, cutting fluid, dirt, metal swarf and other foreign materials should not be allowed to enter the new-oil container or the machine lubrication system.

Avoid eye contact, prolonged or repeated skin contact and inhalation of oil mist or aerosols. Suitable workplace personal protective equipment may include safety glasses, protective clothing, safety footwear and oil-resistant gloves. Nitrile rubber gloves may be suitable for intermittent contact, subject to the workplace risk assessment and glove manufacturer’s recommendations.

Clean spills immediately because the product can create a slippery surface. Prevent spilled oil from entering drains, sewers, soil or waterways. Small spills may be collected with suitable absorbent material. Larger spills should be contained, recovered and placed in correctly labelled containers for disposal through an authorised waste contractor.

Although the Australian Safety Data Sheet classifies RENEP CGLP 68T as non-hazardous and not Dangerous Goods for road and rail transport, it remains a combustible lubricating oil and must be handled responsibly. Consult the latest product label and Australian Safety Data Sheet before workplace use.

Typical property values are representative of normal production and are not intended to constitute guaranteed manufacturing specifications.

Directions for Use

Confirm that ISO VG 68 slideway oil is specified or accepted by the machine manufacturer. Before filling or topping up, clean the reservoir cap, filling point and surrounding area to prevent contamination from entering the lubrication system.

Where practical, drain unsuitable or badly contaminated lubricant and clean the system according to the equipment manufacturer’s maintenance procedure. Avoid mixing RENEP CGLP 68T with unknown products because lubricant mixtures may alter friction behaviour, demulsibility, corrosion protection and additive performance.

Fill the reservoir to the recommended level and check the operation of pumps, metering units, distribution lines and lubrication points. Confirm that oil is reaching each slideway or linear guide at the required rate.

Lubrication intervals should be selected according to the machine design, operating cycle, slideway geometry, feed speed, load and cutting-fluid exposure. Regularly inspect the slideways for chatter, staining, abnormal wear, poor positioning, excessive oil consumption or restricted lubricant delivery.

Where RENEP CGLP 68T is intended to serve both as a slideway lubricant and an HLP 68 hydraulic fluid, obtain confirmation from the machine manufacturer before conversion. Hydraulic compatibility depends on the pump design, seals, operating temperature, filtration requirements and other system-specific factors.

Suitable Industries

FUCHS RENEP CGLP 68T is suitable for professional industrial environments including:

• Metalworking and precision engineering
• CNC machining
• Automotive component manufacturing
• Tool and die production
• General manufacturing
• Machinery and equipment production
• Steel and non-ferrous metal processing
• Mining-equipment workshops
• Maintenance and repair facilities
• Machine tool servicing
• Production engineering
• Industrial fabrication