Sumitomo 1655FEF Pcbn Turning Insert DA90 Diamond Neutral

Product Description

The SUMITOMO 1655FEF is a Polycrystalline Cubic Boron Nitride (PCBN) turning insert designed for precision metal cutting applications. Manufactured in the DA90 series, this uncoated, neutral-hand insert features a diamond insert shape (Shape Code C) with a 4.3 mm inscribed circle and a 0.2 mm corner radius. The PCBN substrate delivers the hardness and thermal stability required for hard-turning ferrous materials and interrupted cuts where conventional carbide falls short. Screw-type holding keeps the insert securely seated under high cutting forces. Licensed machinists and CNC tool setters are the primary users of this insert in production turning environments.

This insert is suited for finish and semi-finish turning operations on hardened steels, cast irons, and similar hard materials. The DA90 series geometry and uncoated PCBN construction make it appropriate for tight-tolerance internal and external turning passes where surface finish and dimensional accuracy are critical. It is used in CNC turning centers and manual lathes equipped for CCMA-style toolholders. Maximum depth of cut is 0.5 mm, making this a dedicated finishing insert rather than a roughing tool.

Key Features

• PCBN (Polycrystalline Cubic Boron Nitride) insert material for hard-turning capability
• Uncoated bright finish with diamond shape (CCMA insert style) for consistent edge geometry
• 0.2 mm corner radius for fine surface finish on tight-tolerance workpieces
• Neutral hand orientation for flexible toolholder setups
• Screw-type insert holding method for positive, repeatable seating
• 7-degree relief angle with no chip breaker, optimized for controlled finishing cuts

Compatibility

Designed as an OEM-style replacement or direct-fit insert for CCMA-style turning toolholders accepting a 4.3 mm inscribed circle, 1.80 mm insert thickness, and 2.30 mm hole diameter per the DA90 series specification.

Installation Notes

Installation of turning inserts should be performed by qualified machinists or CNC tooling technicians with the machine fully powered down and the spindle locked before indexing or replacing the insert. Use the appropriate Torx or hex key to seat the clamping screw to toolholder manufacturer specifications — do not overtighten, as PCBN inserts are brittle and susceptible to fracture under improper clamping loads. Inspect the toolholder pocket for chips or debris before seating the insert. Verify insert orientation and hand designation before resuming operation.