Rego-Fix is a leading tool holder brand based in Switzerland since 1950.
The CAT system utilizes a proven 'fast taper' (7:24) self-releasing format and is common among American machine tools. Note that ISO, CAT, BT, and SK are NOT interchangeable even though they use the same basic taper!.
The ER tool holder system was invented by Fritz Weber, founder of Rego-Fix, and released in 1972. The ER-type system was originally used as a broom head to handle interface! The R in 'ER' stands for Rego-Fix, and represents the company's modification to common 'E' collet design of the early 20th century. Specifically, the modification was adding a groove to the collet which keeps it captive in the nut while installing/removing; eliminating the problem of collets getting stuck in the holders. Upon patent expiry the system was standardized in 1993 under DIN 6499 and is today the most recognizable and commonly used collet system worldwide.
The classic ER interface, tried and true.
Please note that the actual item may not be/look exactly the same as shown in the item picture, and check all available info/links for reference or contact us for clarification.