Iwaki, Japan – November 2026 – Tungaloy Corporation (President: Satoshi Kinoshita, Head Office: Iwaki City, Fukushima Prefecture) is adding the T500D series for ductile cast iron machining to its lineup of CVD-coated grade for cast iron.
Challenges and Trends
Cast iron materials, including ductile cast iron (FCD) and gray cast iron (FC), are widely used in automotive parts such as camshafts and brake discs, as well as in engine and hydraulic valve components for heavy equipment, with ductile cast iron is particularly common in parts that require high tensile strength, impact resistance, and flexibility under heavy or complex mechanical loads. For turning tools used on ductile cast iron parts, there is a strong demand for support of high-speed machining to improve productivity and greater reliability as interrupted cuts become more common on complex-shaped parts. To meet these requirements, tool materials must deliver both excellent wear resistance and excellent fracture resistance, two properties that are inherently difficult to balance.
Product Overview
The new T500D series for ductile cast iron machining comprises two grades, T505D and T515D, and both grades achieve an excellent balance of wear resistance and fracture resistance. T505D is designed primarily for wear resistance in high-speed machining, while T515D significantly improves reliability in interrupted cuts by enhancing fracture resistance. The addition of the new T500D series to the existing T500 series—which delivers outstanding performance in gray cast iron machining—completes Tungaloy’s lineup of CVD-coated grades for cast iron turning, delivering high reliability and exceptional tool life across a wide range of cast iron materials.
Benefits and Features
Feature 1: T500D series delivers excellent performance in ductile cast iron machining
– A fine columnar Al2O3 layer that is 1.4 times as thick as in the previous grade provides excellent resistance to built-up edge formation and edge chipping.
– The total coating thickness, including the continuous columnar TiCN layer, has been increased to 1.3 times that of the previous grade, providing excellent flank wear resistance.
– A thick, high-adhesion bonding layer, twice as thick as in the previous grade, ensures strong adhesion between the Al2O3 and TiCN layers.
– Tungaloy’s proprietary PremiumTec surface treatment smooths the tool surface, significantly reducing built-up edge formation.
– Advanced coating technology delivers an excellent balance of wear resistance and fracture resistance.
Feature 2: Two new grades, T505D and T515D, support a wide range of machining applications
– T505D: Excellent wear resistance for high-speed turning of ductile cast iron.
– T515D: The first-choice grade for ductile cast iron machining for an excellent balance of wear and fracture resistance across a wide range of applications.
Feature 3: Full lineup of cast iron turning grades with the T500D and T500 series
– The product range of the existing T500 series (T505 and T515) has also been significantly expanded.
– With the addition of the T500D series to the T500 lineup, users can now select the optimum grade for their application across a wide range of cast iron turning, including gray cast iron, ductile cast iron, and other cast iron materials, from continuous to interrupted cuts and from finishing to medium and heavy-duty cutting.
Cutting Performance
Tool Life Comparison
| Insert | CNMG120408 |
| Cutting speed | Vc = 200 m/min |
| Feed | f = 0.3 mm/rev |
| Depth of cut | ap = 1.5 mm |
| Machining | Continuous cutting |
| Coolant | Wet |
T505D achieves a tool life more than 1.4 times longer in ductile cast iron machining, thanks to its superior wear resistance!
| Insert | CNMG120408 |
| Cutting speed | Vc = 150 m/min |
| Feed | f = 0.35 mm/rev |
| Depth of cut | ap = 1.5 mm |
| Machining | Interrupted cutting |
| Coolant | Wet |
T515D delivers excellent fracture resistance in ductile cast iron machining!
Success Stories
Improved Tool life
T505D delivers excellent wear resistance at Vc = 300 m/min, achieving 2.5 times the tool life of the competitor.
| Industry | Automotive |
| Component | Automotive parts |
| Material ISO code |  Cast iron |
| Workpiece material | FCD400 / GGG40 |
| Machine(spindle type) | CNC Lathe |
| Tool family | Turning |
| Tool category | External & Face turning |
| Product name | T500Dseries |
| TSR No. | 5693T |
Improved Tool life
T515D delivers stable performance in finishing, achieving twice the tool life of the competitor.
| Industry | Automotive |
| Component | Clutch Parts |
| Material ISO code | Cast iron |
| Work material | FCD400 / GGG40 |
| Machine(spindle type) | CNC Lathe |
| Tool family | Turning |
| Tool category | Face turning |
| Product name | T500Dseries |
| TSR No. | 5694T |
