Challenge 540HT

Slurry Additive for Suspending Non-Treated Abrasives (Single Pass)

CHALLENGE 540-HT evenly disperses and suspends a variety of non-suspension-treated abrasives, including aluminum oxide, cerium oxide, zirconium oxide, along with silicon carbide, boron carbide, synthetic and natural diamond, and garnet. Because of its superior suspension characteristics, CHALLENGE 540-HT also reduces the amount of abrasive grain needed by up to 50%, while providing equal, and often greater, stock removal rates. A next-gen version of this product has been developed, see CHALLENGE 543-HT for more information. Benefits: • Flatter parts • No scratching • Less sub-surface damage • Easier post-lap cleaning • Increased removal rate • More consistent results • Reduced abrasive usage

Challenge 540HT Details

Base Material:


Shelf Life:

24 Months


Product is available in 5-gallon pails and 55-gallon drums.


Ceramic, Fused Silica, Glass, Poly Carbonate lens

Similar Products

Challenge 543-HTChallenge 550-HTChallenge 555-HT
Base Material WaterWaterWater
Specific Gravity11.01
Category - Lapping Additives

Handling Instructions

CHALLENGE 540-HT should be mixed with deionized water and abrasive using the following slurry formula: 77-80% water,16-18% abrasive, 4-6% CHALLENGE 540-HT. Use an agitator with a marine type propeller and a motor capable of 1750 RPM. Use a low shear dispense pump for feeding the mixed slurry onto the lap.

Disperse the abrasive with DI water at 1000 rpm for 3 minutes. Add 540-HT. Mix for approximately 30 minutes depending upon abrasive surface chemistry. A small vortex should form at the surface of the slurry. Turn the mixer off, or to a maximum of 50 rpm.


Product should be stored in a temperature controlled environment. Prolonged exposure to temperatures at or below 32° Fahrenheit (0°C) is discouraged. Prolonged exposure to temperatures at or above 100° Fahrenheit (38°C) is also discouraged. In addition, material should always be sealed when not in use to prevent evaporation.


Dispose of in accordance with all applicable local regulations.

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