Castrol Alusol SL 51 XBB

Castrol Alusol SL 51 XBB is a high-performance soluble metalworking fluid formulated with Castrol’s advanced XBB technology to deliver exceptional machining precision, fluid stability, and environmental compliance.

This next-generation coolant is free from boron, chlorine, and formaldehyde-releasing agents, helping you meet modern waste treatment and safety regulations without compromising on quality or performance.
The result is a cleaner, longer-lasting fluid that helps reduce maintenance, extend tool life, and lower overall operating costs — ideal for modern, high-precision manufacturing environments.

Optimised Machining for Aluminium and Beyond

Designed especially for aluminium machining, Castrol Alusol SL 51 XBB provides outstanding lubrication and cooling, helping to enhance tool life and deliver superior surface finishes.
Its additive package is carefully balanced to reduce friction and wear while maintaining excellent cleanliness and fluid stability, even in demanding applications.

With low-foam performance under recommended water conditions, Alusol SL 51 XBB ensures smooth, reliable operation in both high-speed and high-pressure systems, making it ideal for precision machining operations across industries.

Why Choose Castrol Alusol SL 51 XBB?

Castrol Alusol SL 51 XBB combines performance, reliability, and environmental responsibility to meet the demands of today’s precision manufacturing.
Its boron- and chlorine-free formulation aligns with strict environmental standards, while its advanced additive technology ensures superior machining quality and reduced downtime.

With Castrol’s XBB technology, you can rely on long-lasting fluid stability, cleaner operation, and consistent performance — all while supporting sustainable, cost-efficient production.

Castrol Alusol SL 51 XBB is suitable for both large central systems and single sump machines, offering flexibility and performance consistency in a wide range of manufacturing environments.

While it is optimised for aluminium and aluminium alloys, it also performs effectively on ferrous and other non-ferrous materials, making it a versatile choice for aerospace, automotive, and general engineering applications.

Its excellent wetting and cleaning properties reduce coolant drag-out, keeping machine tools and components cleaner, and improving overall shop-floor efficiency.

XX suggested core application

X possible application, please consult a Castrol representative prior to use

Castrol Alusol SL 51 XBB Lubricant Advantages:

• Free from boron, chlorine, and formaldehyde-releasing agents – supports compliance with current environmental and waste treatment regulations.

• Extended fluid life – helps reduce maintenance frequency and minimise machine downtime.

• Low foam in recommended water conditions – ensures reliable, consistent operation in modern equipment.

• Advanced lubrication package – helps extend tool life and improve surface finish on aluminium machining.

• Excellent wetting and cleaning properties – reduce coolant drag-out and promote cleaner machines and components.

• Versatile performance – suitable for a wide range of materials and applications, supporting product consolidation and simplified fluid management.

Recommended Dilutions:

Grinding 6-7%
General Machining 6-8%
Drilling 7-9%
Reaming and tapping 8-10%
Broaching 8-10%
Water range 100-800 ppm CaCO3

Storage & Safety:

To avoid product deterioration, always keep the container/drum tightly sealed. For optimum product stability, store between 5°C/41°F and 45°C/113°F in a cool, dry place away from direct sunlight. Prevent exposure to frost and avoid water ingress. It is preferable to store Castrol Alusol SL 51 XBB indoors.
For more details, please refer the product safety data sheet.

Download Technical Data Sheet

Download Safety Data Sheet

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