Accupro 785058 ER40 Collet 0.843 Inch

Product Description

The ACCUPRO 785058 is an ER40 series collet designed for use in CNC machining centers, manual mills, and other rotating spindle equipment that accepts ER40 toolholding systems. This collet clamps workholding or cutting tool shanks with a maximum capacity of 0.843 inches and a minimum collet capacity of 0.813 inches, giving it a 0.030-inch clamping range typical of ER-style collets. The body measures 1.75 inches wide, 1.75 inches in length at the base, and 2 inches in height. Weighing 0.6 pounds, it is machined to ER40 dimensional standards for accurate runout and secure tool retention in production and job-shop environments. Machinists and CNC operators are the primary installers.

This collet is suited for use in any spindle, collet chuck, or toolholder that is bored and threaded to the ER40 standard. Common applications include end mill holding, drill holding, reaming, and tapping operations in ferrous and non-ferrous materials. The 0.843-inch nominal size targets tool shanks in that specific diameter range, making it a direct replacement or additional collet for shops running ER40 toolholding systems on vertical machining centers, horizontal machining centers, or manual knee mills.

Key Features

• ER40 collet series for compatibility with ER40-standard chucks and toolholders
• 0.843-inch nominal collet size with a clamping range down to 0.813 inches
• Compact profile: 1.75 inches wide, 1.75 inches at base, 2 inches tall
• Lightweight at 0.6 pounds for minimal spindle imbalance contribution
• Sold individually, allowing single-collet replacement or incremental kit building

Compatibility

Designed for use with ER40-standard collet chucks and toolholders that accept the ER40 collet series. Specific machine or chuck model compatibility was not provided in the product data.

Installation Notes

Installation is performed by machinists or CNC setup technicians. Before inserting or removing a collet, ensure the spindle is fully stopped and the machine is powered down or placed in an e-stop state. Seat the collet fully into the ER40 nut before threading onto the chuck body to prevent cross-threading or collet damage. Tighten the nut using a proper ER spanner wrench to the chuck manufacturer's specified torque procedure — do not use pipe wrenches or improvised tools on precision collet nuts.