Machinists are often frustrated by the poor performance and limited life of their small carbide tools. If this happens in your shop, and you are using quality cutting tools, the problem may not be with the actual cutters, but with your tool collets. The collets aren’t holding your cutting tools securely in place, causing movement and inaccuracy.

Standard ER collets of ¼ in. and smaller have a tall counter bore and a shallow collet pocket. Typically 40% of the collet extends out of the collet pocket, which means that 40% of the jaws’ surface area cannot effectively close on the tool shank because they are unsupported by the pocket walls.

With so much of the collet exposed, friction is caused when the ER nut meets the collet shoulder. That friction twists the collet jaws as they are tightened, distorting the collet axis and causing variable TIR and inconsistent results. This is especially true for ER collets with diameters of 6mm or less; the tiny jaws cannot deliver the proper holding forces and rigidity needed for consistent TIR.

In addition to unpredictable results, unwanted flexing and slipping of the drill bit causes uneven wear and shortens the life of the tool. Tally the excess inventory costs and the time lost to replace worn cutters —that’s money and time wasted.

Techniks Solution: DNA Collets

The tool holding masters at Techniks have devised a solution to the small tool holding problem. Their DNA collet line provides more shank support deeper into the pocket and more rigidity than smaller-diameter ER collet nuts. DNA collets are designed with a shorter counter bore, allowing more of the tool shank to be clamped and held by the collet jaws. DNA collets feature six large jaws as opposed to the standard eight smaller jaws on an ER collet. DNA collets are designed for tool diameters of 6mm or less and work with all ER tool holders. They deliver TIR of .0002 — a consistency that provides accurate results and extends the life of your tools. ETS/DNA collets are coated for 75% more holding power. Available accessories include nuts, wrenches and adapters.

Always remember to:

• Clean your assembly before using: The chuck, collet and ER nut must be free of debris and dirt to ensure optimal results
• Likewise, tighten to specs. Never overtighten a collet.
• Use only the tool size appropriate for the collet; do not try to use a tool with a shank that exceeds the maximum collet diameter.

Our mission at BlackHawk Industrial is to provide innovative, value-added services and products that reduce our customer’s total cost. Our machine tool professionals are happy to help. You can contact us for more information about the Techniks DNA Collets by phone at 855-610-1001 or on our Contact Us web page.