The original W.S. Tyler Ro-Tap® is the industry standard for consistent, repeatable particle size testing. With both mechanical and electronic options, W.S. Tyler offers multiple solutions to fit your laboratory needs.


The Ro-Tap is the required test sieve shaker in many industrial specifications. Currently, there are no industry standards governing the calibration of the unit itself. W.S. Tyler recommends the product users develop their own quality control program.

Today, the Ro-Tap is available in 6 models. The RX-29 for 8" test sieves, RX-30 for 12" test sieves, RX-94 Duo Shaker for two 8" test sieve stacks, RX-29 E (Electronic) for 8" sieves, RX-30 E (Electronic) for 12" sieves, and RX-812 Coarse Sieve Shaker.
Metric equivalents: 8" diameter = 200mm diameter and 12" diameter = 300mm.

The Ro-Tap Test Sieve Shaker series are available in 110v or 220v power options. The Ro-Tap E units are CE Approved. All test sieve shakers are supplied with an operations manual, including unit diagrams that feature parts schematics. The units are well built, durable, and require little, if any, maintenance.