R8 collets are obviously as common in the shop environment as the Bridgeport mill. However, not all R8 collets are the same. The most common R8 collet on the market is a 2 piece arrangement consisting of the R8 collet body and bushing. The bushing is first threaded into the body and then one of two common methods is used to secure it in the body; swaging or pinning. In the mid 50’s thru the early 70’s these manufacturing processes were used at Hardinge as well. The bushing however, was prone to failure and had to be repaired or replaced.
As a result, the Hardinge R8 collet was redesigned to eliminate the bushing. A swaging process was added to cold form the new R8 blanks into a one piece collet. The ID is then drilled and tapped to receive the draw bar. All Hardinge R8 collets are hardened and ground to provide the highest quality, accuracy and confidence. You will never have to repair or replace a bushing in this Hardinge R8 collet.
Posted by hardingegroup 
