Seco 00018920 Differential Screw 1/4-28 Thread Turning

Product Description

The SECO 00018920 is a differential screw designed for indexable turning toolholders. Differential screws use opposing thread directions on a single fastener to produce precise, low-profile clamping force when securing indexable inserts. This screw features a 1/4-28 thread size, a right-hand thread length of 0.37 inches, a left-hand thread length of 0.37 inches, and an overall length of 1.00 inch. It is compatible with the CL-20 clamp style. Machinists, toolroom technicians, and CNC setup personnel install this type of fastener during insert changes and toolholder maintenance on turning centers and manual lathes.

This differential screw is intended for use in indexable turning applications where a CL-20 clamp secures the cutting insert to the toolholder body. It is sold individually per package with a minimum order quantity of 10 pieces. The screw corresponds to industry standard number 18920 and is a direct replacement or service fastener for toolholders requiring this specification. It is suited to production turning environments where insert indexing is performed at regular intervals.

Key Features

• 1/4-28 thread size for positive engagement with CL-20 clamp-style toolholders
• Dual opposing thread design — right-hand and left-hand — generates controlled clamping force with minimal torque input
• Right-hand thread length of 0.37 inches and left-hand thread length of 0.37 inches
• Overall length of 1.00 inch suits standard indexable turning toolholder pocket depths
• Compatible with CL-20 clamp hardware for indexable turning inserts
• Corresponds to industry standard number 18920 for cross-reference and procurement

Compatibility

Designed for use with CL-20 clamp-style indexable turning toolholders requiring a 1/4-28 thread differential screw. Compatible hardware type is the CL-20 clamp as stated in product specifications.

Installation Notes

Installation is performed by machinists or toolroom technicians during routine insert indexing or toolholder service. Ensure the toolholder is removed from the machine or the machine is in a safe, de-energized state before handling cutting inserts or fasteners. Use the correct hex key or Torx driver as specified by the toolholder manufacturer — do not substitute driver sizes, as differential screws are prone to head damage when driven with ill-fitting tools. Inspect the screw threads and clamp seat for chips or debris before reinstalling to ensure proper seating of the indexable insert.