Cutting tools for miniature dental, medical parts

PHOTO: ISCAR METALS USA

Miniature dental and medical components present a formidable, yet dynamic, challenge to cutting tool manufacturers. Enterprising surgeons and dental professionals, collaborating with medical device implant companies, are advancing and revolutionizing medical procedures.

However, each new device requires correspondingly advanced tools and geometries to precisely create complex shapes while ensuring consistent surface finishes.

Most medical screws and implants are produced from titanium superalloys, although stainless-steel hard materials are used when a special ratio of depth-of-cut (DOC) to chip thickness is required. Titanium and stainless-steel materials are gummy and cause built-up edge (BUE), which wears down edge sharpness. High temperatures generated during chip breaking shorten tool life and damage surface quality.

Iscar’s custom tool assemblies built to the ISO 13399 standard provide cutting tools for these parts – specifically dental screws and four components for hip joint replacement implants: femoral head, acetabular shell, femoral stem, and bone plate.

Dental screws

SwissCut, used for turn threading, reduces setup time and eases indexing without removing the toolholder from the machine. Inserts are equipped with chip deflectors for machining small parts.

SwissTurn toolholders have a mechanism optimized for insert clamping and replacement on Swiss-type machines and JetCut high-pressure coolant tools.

For slot milling, chatter-free endmills maximize stock removal, eliminate vibration, and reduce cycle time.

PentaCut parting and grooving inserts perform cut-off operations. It’s a stronger insert for higher machining parameters on soft materials, parting of tubes, and small and thin-walled parts.

SwissCut tools are used in face and OD turning (screw head turning), while drilling is handled by SolidDrill with drilling depths of 3xD and 5xD.

Thread milling operations feature SolidThread, with short, three-tooth cutting zones with three flutes and released necks between the cutting zone and shank.

SolidMill solid carbide endmills with 2-flute, 30° helix medium length, perform key head milling operations.

Hip joint

Femoral head, acetabular shell, femoral stem, and bone plate machining.

ISOTurn turning tools support rough turning, performing most of the industry’s chip removal from finishing to roughing. For profile machining, intricate and precise V-Lock, V-shaped, special profile grooving inserts range from 10mm to 36mm. Precision ground and utility Cut-Grip full-radius inserts can perform semi-finish turning.

SumoCham drilling tools perform rough drilling, offering fast metal removal and economical indexing. A clamping system improves productivity and a shank with twisted nozzles delivers a stable body.

Chatter-free, 4-flute endmills perform semi-finish milling and feature 38° helix and variable pitch. ChamGroove internal grooving inserts, with 8mm, 11mm, and 15mm diameters, incorporate internal coolant for semi-finish grooving.

Semi-finish internal turning is handled by ISOTurn inserts with SwissTurn toolholders, while the cut-off operation uses Do-Grip twisted double-sided parting inserts that eliminate DOC limitations.

For rough turning, the SwissTurn ISO standard inserts small shank sizes support rough turning. Standard geometry inserts with precision ground cutting-edges and small radii are available.

Semi-finish turning can be performed with Cut-Grip inserts.

Heli-Grip double-ended inserts perform rough internal turning, as the twisted design allows them to groove deeper than the insert length. Internal finish milling is handled by 3-flute, 30° helix, SolidMill endmills. Endmills with four flutes, 38° helix, and variable pitch for chatter dampening perform finish shouldering. A special-shaped endmill for upper and bottom chamfering operations follows drilling.

SolidDrill solid carbide drills perform drilling. A right-hand cut is available with and without internal coolant nozzles.

Thread milling, performed by SolidMill endmills, integrate coolant holes for ISO thread profiles. ISO standard inserts with SwissTurn toolholders featuring JetCut high pressure coolant support rough turning while Cut-Grip precision inserts perform external grooving.

Four-flute, 38° helix, variable pitch SolidMill endmills with 3xD relieved necks perform final milling.

Multi-Master endmills perform slotting, featuring no setup time, quick-change carbide-thread connections, and conical and face contact for high precision.

Spot milling is performed by 4-flute, 38° helix and variable pitch for chatter dampening, and 3xD relieved necks SolidMill endmills.

Multi-Master endmills with indexable solid carbide heads support slotting. Precision ground ISO standard geometry inserts used with SwissTurn toolholders featuring JetCut high-pressure coolant perform turning.

SolidMill 3-flute, 30° helix endmills are employed for profile milling, and 4-flute SolidMill endmills with chatter-dampening 38° helix and variable pitch with 3xD relieved necks perform face milling.

For rough milling, finished endmill geometries allow simultaneous roughing and finishing. Multi-Master interchangeable solid carbide tapered heads allow finish milling, where curved surfaces can be machined by tilting the tool and applying a large corner radius at small cutting depths. Shouldering, with chatter-free endmills with high material removal rates, eliminates vibration and reduces cycle time.

For final milling, use Multi-Master 4-flute, 30° helix short solid carbide ball-nose endmills. SolidDrill with 4xD drilling and no coolant holes provide stable, accurate drilling. SolidThread 55° or 60° profile thread mills handle mill threading.

Iscar Metals USA
https://www.iscarmetals.com
SOUTHTEC 2019 Booth #2229