THK Original Grease AFA Grease

AFA Grease is a high-grade grease that possesses a long service life, excellent water resistance, and low sliding resistance through the use of high-grade synthetic oil as the base oil and a ureabased consistency enhancer.

Features

• Low sliding resistance

As the kinematic viscosity of the base oil is low, it is ideal for long-stroke, high-speed LM Guide operations.

• Water resistance

It is less vulnerable to moisture penetration than other types of grease because of its high water resistance.

Representative Physical Properties

Item	Description
Tested model	SHS25RUUC0
Speed	2.0m/s
Stroke	2300mm
Amount of lubricant injected	2.5 cm3 (initial lubrication only)

Sliding Resistance Comparison

Item		Representative value	Test method
Consistency enhancer		Urea-based
Base oil		High-grade synthetic oil
Base oil kinematic viscosity: mm²/s(40℃)		25	JIS K 2220 23
Worked penetration (25°C, 60 W)		285	JIS K 2220 7
Mixing stability (100,000 W)		329	JIS K 2220 15
Dropping point: °C		261	JIS K 2220 8
Evaporation amount: mass% (99°C, 22 h)		0.2	JIS K 2220 10
Oil separation rate: mass% (100°C, 24 h)		0.5	JIS K 2220 11
Copper plate corrosion (B method, 100°C, 24 h)		Accepted	JIS K 2220 9
Low-temperature torque: mN-m (‒20°C)	Starting	170	JIS K 2220 18
	Rotational	70
4-ball testing (welding load): N		3089	ASTM D2596
Service temperature range: °C		‒45 to 160
Color		Brown

Rotational Torque Testing with Ball Screw Grease

1 cm³ of grease was applied to the KR4620A + 640L LM Guide and 2 cm³ to the ball screw (initial injection only), and then the torque was measured at each motor rotation speed. The output values on the driver torque monitor were used for the torque measurements.
 

Grease used	Central value of dynamicviscosity mm²/s (cSt) (40°C)	Dynamic viscosity range mm²/s (cSt) (40°C)	Rotational speed
			100 min⁻¹	1000 min⁻¹	2000 min⁻¹	4000 min⁻¹
AFA Grease	25	22.5 to 27.5	11.3	11.3	12.3	14.6
Lubricating oil VG32	32	28.8 to 35.2	11.2	10.8	13.4	14.7