ER-Style Toolholding System
ER-style and R8 collet holders are now offered for use on knee mills. Holders are stocked in three sizes to hold ER-style toolholder collets to grip drills, taps, reamers, end mills, boring bars and special round shank endworking tools. One holder will accommodate a range of collets, the company says. The maximum round tool capacities are 3/8" (ER16), 25/32" (ER32), and 1" (ER40).
The collets are of a multi-slot design, which are said to provide maximum gripping force for efficient "push-back" control. This control helps prolong tool life, which in turn, reduces machine downtime to produce more parts per hour. The manufacturing process ensures each collet will have a total indicator reading of 0.0005" or less, the company says.
The standard R8 collets’ "one-piece" construction is said to eliminate breakage associated with other brands that have a two-piece design with a separate bushing. In the two-piece design, the bushing often breaks off in the spindle and results in the costly replacement of the spindle drawbar as well as the collet, according to the company.
Editor PickBroaching Toolholder Interchangeable with ER Collet Chucks
Eastec 2017: Somma Tool Co. offers a new style of broach toolholder designed to be interchangeable with any style of ER collet chuck.