For that reason, we denote our collet grades with a TIR specified at the collet face (TIRF) AND at a point 1" down the calibration blank (TIR1") as shown in the image on the left. These values are listed in the table on the right.

ER 11Collet holder

The measurement reported is generally the one taken at the 4 X D point on the blank. No mention is made of the other measurement, or the phase angle between them. Without these 2 pieces of infomation, there is no way to determine what the TIR will be farther from the collet face. It may not souund like much of a problem but, if the two measurements are exactly 180° out of phase, a tool clamped in the collet will be skewed across the central axis with the TIR increasing the farther you get from the crossing point. For collets used with microtools (like ours), it is more important to know how the tool is "wobbling" at the length where it is actually cutting. For 1/8" shank bits with an overall length of 1-1/2", this is typically about 1" from the collet face.

ER 11COLLET dimensions

Er 11 colletsamazon

Orders received by noon on the day before the beginning of the holiday should ship the same day.Normal operating hours resume on the first business day following the last day of the holiday.

Generally speaking, collet manufactures specify a single value for the runout (TIR) of a collet. Often it is not clear where, relative to the collet face, the measurement was made. International standards for ER style spring collets (DIN6499 and ISO15488) specify that the TIR of a collet should be determined at the collet face and at a distance not less than 4 times the clamping diameter (D). For example, the TIR of a collet with a clamping diameter of 1/8" (3.18mm) should be measured as close to the face as possible and at a distance not less than 4 X 1/8" = 1/2" (12.7mm) along a certified precision calibration blank.