Expanded Chuck Series Doubles Clamping Force

Big Kaiser has expanded its Unilock 138-series round chuck with the ESM 138 Turbo and Ergo 138 models. These new versions share the same fundamental body dimensions for diameter, bolt hole pattern, open port orientation and knob type as the original ESM 138 model. The ESM 138 Turbo and Ergo 138 also share features including quick setup and loading, self-guided top-side mounting, and zero-point clamping.

The ESM 138 Turbo chuck has a closed back for “turbo” capability, which more than doubles the spring-only clamping force to roughly 3,520 lbs by connecting an air source to either the 1/8G turbo port on the OD or the underside O-ring port. The sealed back also protects the chuck’s piston from contaminants, reducing maintenance while improving consistency. Slotted pin actuation uses a dual-angled slot for faster and stronger transfer of clamping force upon closing as well as a quicker, even release of the knob.

The Ergo 138 also has a sealed back, protecting the internal mechanics from contamination and making it “turbo” capable. The back cover has an air blast port which cleans the knob upon entry. By connecting an air source, operators can clean the chuck and knob before locking it, ensuring firm and consistent positioning during loading/unloading and preserving the equipment. This feature makes the chuck ideal for fine-particle materials like cast iron. While exchangeable with the standard ESM 138 model, the Ergo 138 is 11 mm shorter and includes an expanded inner contact ring for a larger contact surface area.