Lubricants for the Rubik’s Cube and Other Puzzles

Lubricant reduces friction between the parts of a puzzle, makes the turning smoother and more controllable, and decreases plastic wear and noise during turning.
Modern lubricants for the Rubik’s Cube most often use:

• silicone oils of different types;
• fluorinated (PFPE) lubricants;
• their combinations with various additives.

Below is a short explanation of the main types.

Linear Silicone Oils

What they are

Linear silicone oils are clear liquids based on polydimethylsiloxane (PDMS).
The word “linear” means that the molecules of this oil are arranged in long flexible chains, similar to threads.

Thanks to this structure, the oil:

• provides good glide and spreads easily over the surface;
• is chemically inert toward plastic and metal;
• does not oxidize and almost does not dry out under normal conditions.

In practice, linear silicone oils are most often used as the base of cube lubricants.

Viscosity and feel while solving

The key parameter of such oils is their viscosity:

• Low viscosity
  Makes the cube faster and lighter to turn. The effect is strong but usually less long-lasting.
• Medium viscosity
  A compromise between speed and control. This option is often chosen as a “universal” lubricant for everyday training.
• High viscosity
  Slows the turning but adds smoothness and stability, reducing vibrations and looseness. It is often used in big cubes (4×4 and larger) or very light modern 3×3 cubes that you want to make more stable.

Cyclic Silicones

What they are

Cyclic silicones (for example, decamethylcyclopentasiloxane, D5) are also silicone liquids, but their molecules are closed into rings instead of being stretched into chains.

Because of this structure, they:

• have very low viscosity (they are very thin liquids);
• spread very well over the surface of the parts;
• are more volatile and evaporate relatively quickly.

Role in puzzle lubricants

In cube lubricants, cyclic silicones are used:

• as a very “fast” component that noticeably speeds up the puzzle immediately after application;
• as a carrier for other silicone oils in fast, light-feeling formulas and sprays.

Typical behaviour: right after application the cube feels much faster, then part of the effect decreases as the substance evaporates. For this reason, cyclic silicones are often applied in addition to a thicker, longer-lasting lubricant.

Grease-Type Lubricants

What they are

Grease-type lubricants are lubricants where a liquid oil (silicone or fluorinated) is thickened to the consistency of a cream or paste.
Usually a thickener (for example, silicon dioxide) is added to the oil, and as a result you get:

• a dense, viscous consistency;
• a lubricant that stays in place well and almost does not run off;
• a thicker and more stable layer between the parts.

Where they are used in cubes

In puzzles, grease-type lubricants are used where you need:

• a heavier and smoother feel;
• less play and reduced clicking noise of the parts;
• a long-term effect without frequent maintenance.

Most often such lubricants are applied in small amounts to the support surfaces and “feet” of the pieces, and a thinner oil is additionally used on the sliding surfaces to adjust the speed.

Fluorinated Lubricants (PFPE)

A separate group consists of fluorinated lubricants based on perfluoropolyether oils (PFPE). They are characterized by:

• high chemical inertness (they do not react with plastic or metals);
• resistance to oxidation and evaporation;
• a very long service life inside the mechanism.

In puzzles, such lubricants provide:

• a very smooth and predictable feel during turning;
• stable performance over a long period of time.

Because of the higher price and the noticeable “heavy” feel when applied in excess, fluorinated lubricants are often used locally or in combination with common silicone oils.

Summary

In short, modern lubricants for the Rubik’s Cube are various combinations of:

• linear silicone oils (the base that defines speed and control);
• cyclic silicones (very fast and light feel right after application);
• grease-type lubricants (smoothness, silence, reduced play);
• fluorinated lubricants (durability and stability).

Different products use these components in their own proportions, so each lubricant gives slightly different sensations when solving.