CAI 70-West Cerchar abrasiveness index tester - ASTM D7625-10


The CAI 70 accurately determines the rock abrasivity index (CAI) employed for the classification of rock materials in terms of abrasivity. The CAI is a dimensionless unit obtained from measuring the wear on a HRC55 Rockwell Hardness steel stylus tip after it has been used to abrade a specimen with a 70N normal force. The apparatus comprises a stationary stylus, a deadweight (70N) placed on top of the stylus, a stiff load frame, a rigid vice to firmly clamp the rock sample and a cross table with 2 adjustable axes for specimen alignment along the two horizontal axes. The device comes with a graduated knob for 0.01 mm accurate scratch distance control. Options include an indenter visualization system, spare indenters and a sharpening tool. The former encompasses a digital camera with indenter support and inspection software to reveal the wear amount which is then correlated to the abrasiveness index (CAI). The sharpening tool rapidly sharpens a worn stylus for subsequent scratch tests.

For more information, please visit Floxlab's website:  floxlab


Standard : ASTM D7625-10.
Manufacturer : Floxlab
Load: 70 N
Maximum specimen height: 150 mm (6 inches)
Maximum specimen diameter: 76 mm (3.0 inches)
Scratch distance precision: 0.01 mm
Steel Stylus: Rockwell Hardness HRC 54/56
Weight: 25 kg
Dimensions (WxLxH): 330 x 500 x 500 mm


* ASTM-compliant, West model
* Easy manual handling
* Features precision slide for smooth movement of the rock specimen over the required scratch distance
* Easy adjustment of the daylight for different specimen heights