Ground roughness is Ra0.4 Microns, plus overall fine polish. Our high-precision collet are distinguished from other low-precision collet, and we manufacture them in strict accordance with the precision written in the description. Each collet is manually tested after it has been processed and produced. It will be put into use after it has passed the test. Your satisfaction is our long term pursuit and up-most concern.Please kindly help to test the items again in order to eliminate improper use factor. We understand the concerns you might have and we will try our best to resolve the problem for you. We will try to answer most emails within 2 days. Certain images/photos are the copyrighted property of JupiterImages and are used with permission under license. The item "25Pcs ER32 Collet Set 1/16-3/4 by 16th and 32nd Industrial Grade Accurate USA" is in sale since Sunday, November 8, 2020. This item is in the category "Business & Industrial\CNC, Metalworking & Manufacturing\Workholding & Toolholding\Workholding\Collets\Spring Collets". The seller is "gura-1563" and is located in La Puente, California. This item can be shipped to United States.