Tungaloy Grade Chart & ISO Equivalents

Tungaloy publishes the substrate numbers most makers keep internal. That makes its chart the most useful benchmark available for judging any alternative quote — here it is, with the trade-offs made explicit.

How a Tungaloy grade code is built

Tungaloy leans on a numerical ladder more than a letter prefix, which makes its grades unusually easy to rank once you know the pattern:

• T9xxx — the steel and cast iron CVD range. Published in matched pairs: T9205/T9105, T9215/T9115, T9225/T9125, T9235/T9135. The 92xx and 91xx members of each pair share an application class on slightly different substrates.
• T6xxx — CVD for stainless (T6120, T6130, T6225).
• T5xxx — CVD for cast iron (T5105, T5115, T515, T5125).
• AH — PVD, mainly stainless and heat-resistant alloys (AH6225, AH8015).
• TH — uncoated for non-ferrous (TH10).

Common Tungaloy grades and their ISO classes

Substrate hardness, transverse rupture strength and coating thickness are from Tungaloy’s published T9200-series specification sheet. The T92xx and T91xx members of each pair target the same application class on different substrates — do not treat them as interchangeable on an unstable setup.

Why the T9200 sheet is worth reading even if you don't buy Tungaloy

Tungaloy publishes the numbers most manufacturers keep internal, and they make a useful benchmark for judging any alternative quote:

• Hardness falls as toughness rises, and you can see exactly how much. From T9205 to T9235, substrate hardness drops from 91.5 to 89.0 HRA while transverse rupture strength rises from 2.4 to 2.7 GPa. That is the whole trade in two columns.
• Specific gravity tracks the cobalt content. It falls from about 14.2 to 13.6 across the same four grades. Tungsten carbide is dense and cobalt is not, so a lower specific gravity means more binder and less carbide. If a plant claims a P10-grade substrate but the part weighs like a P30, the substrate is not what the label says. We weigh and measure rather than assume.
• The coating is 18 µm across the family. One thickness, four substrates. If an equivalent quote specifies the same coating chemistry at 8 µm, you are not being offered the same tool.

Chipbreakers matter as much as the grade

A grade decides how long the insert lasts. The chipbreaker decides whether the operation runs at all. Tungaloy's range uses short codes: TF and TSF for finishing, TM for medium cutting, PM and SW for medium-to-heavy, FW for wiper finishing.

Two published examples show how the two halves combine in practice:

• WNMG060408E TM, grade T9215 — SCM415 steel, V_c 240 m/min, f 0.1–0.25 mm/rev, a_p 1 mm, wet, external face turning.
• DNMG110408E TSF, grade T9215 — S45C/C45 shaft, V_c 260 m/min, f 0.2 mm/rev, a_p 1 mm, wet, external turning.

Note both use the same grade with different chipbreakers. Specifying a grade without specifying the breaker is only half an order.