ER40 Collets – RD40 Collets The ER40 Collet /RD40 system are standardized and manufactured as per DIN 6499 standard guidelines and are truly interchangeable. This becomes important to users that may have toolholding systems from different Toolholding System Manufacturers. Lexis RD 40 Collet / ER40 Collets are designed to collapse with 1mm or .039. Never try to install a cutting tool with a larger shank than the maximum or nominal diameter of the collet to expand the collet. For example: If the cutting tool shank is 4.2mm a 4-3mm is not suitable. A 4.5-3.5mm collet would be required. Sealed Collets for coolant through applications do not have a collapse range, and must be used at exact size. Maximum tightening torque for ER40 Collet is 90 ft/lbs. Lexis RD 40 Collet / ER40 Collets metric sizes starting from 4-3mm Dia to 26-25mm with 1mm incremental and RD 40 Collet / ER40 Collets Inch sizes available from 1/8 to 1Inch. Lexis ER 40 Collet RD40 Collet ER40 Collet ER Collets ER40 Collets ER40 Coolant Collet ER40 Sealed Collet ER40 Tap Collet ER40 Tap Sealed Collet