GGG-NiCr35.3 combines the highest nickel content in the chromium-bearing Ni-Resist family — roughly 34–36% — with 2.0–3.0% chromium. That pairing gives it a fully austenitic, non-magnetic matrix with the strong corrosion resistance and low-temperature toughness that high nickel content provides, plus the added oxidation resistance chromium brings for hotter, more oxidizing service than the chromium-free GGG-Ni35 can comfortably handle. It sits as something of a middle ground between the ultra-stable, low-expansion GGG-Ni35 and the more oxidation-hardy lower-nickel NiCr grades.
Because it carries so much nickel alongside meaningful chromium, GGG-NiCr35.3 is generally reserved for the more demanding corrosion and heat-cycling applications where the added alloy cost is worth it — think seawater-exposed pump and valve components, marine hardware, and process equipment that sees both aggressive chemical attack and repeated thermal cycling. It's a premium grade within the family, chosen when neither a chromium-free nor a lower-nickel option offers enough margin.
| Standard | Designation |
|---|---|
| DIN 1694 | GGG-NiCr35.3 |
| Wnr. (Werkstoffnummer) | 0.7685 |
| ASTM A439 | Type D-5B |
| BS | S-NiCr 35 3 |
| AFNOR | S-NC 35 3 |
Cross-standard matches are based on comparable nickel/chromium content and mechanical property requirements; always confirm against the specific standard revision your drawing calls out.
| Element | Content |
|---|---|
| Nickel (Ni) | 34.0 – 36.0% |
| Chromium (Cr) | 2.0 – 3.0% |
| Silicon (Si) | 1.5 – 2.8% |
| Manganese (Mn) | 0.5 – 1.5% |
| Carbon (C) | 2.4% max |
| Phosphorus (P) | 0.08% max |
Composition reflects the ASTM A439 Type D-5B specification window, the closest internationally recognized reference for this nickel/chromium content and structure. Confirm against your mill certificate for critical corrosion- or heat-service applications.
GGG-NiCr35.3 combines the toughness of a very high nickel austenitic matrix with the abrasive wear contribution of chromium carbides, making it one of the more demanding Ni-Resist grades to machine. Cutting forces run high, chip formation tends toward long and gummy rather than short and brittle, and the chromium carbides accelerate flank wear beyond what a chromium-free high-nickel grade like GGG-Ni35 would produce at the same speed.
Work hardening is a persistent concern with this matrix, so a consistent, adequate feed that keeps the tool cutting rather than rubbing is essential — dwelling or light finishing passes are where this alloy tends to bite back hardest. A sharp, positive-rake cutting edge that shears the material cleanly, combined with rigid, vibration-free tooling, does the most to control both tool wear and surface finish.
Plan on reduced speeds, a tough and heat-resistant coated carbide grade, and generous coolant to manage the heat this combination of high nickel toughness and chromium-carbide abrasiveness generates at the cutting edge.
| Operation | Vc (m/min) | Vc (SFM) |
|---|---|---|
| Turning | 75 – 110 | 245 – 360 |
| Milling | 50 – 75 | 165 – 245 |
| Parting | 30 – 52 | 100 – 170 |
| Grooving | 50 – 75 | 165 – 245 |
| Drilling | 35 – 62 | 115 – 205 |
Speeds are reduced relative to standard ferritic ductile iron, reflecting this grade's combination of high-nickel toughness and chromium-carbide abrasiveness. Values assume a well-matched insert grade, rigid clamping, good-quality raw material, and short tool overhang.
| Grade | Coating | ISO Application Range |
|---|---|---|
| FM2543 | CVD | K20 |
| FM2553 | CVD | K30 |
| Grade | Coating | ISO Application Range |
|---|---|---|
| FM2543 | CVD | K20 |
| FM2553 | CVD | K30 |
| Grade | Coating | ISO Application Range |
|---|---|---|
| FM125 | PVD | K15 – K35 |
Favor the tougher, higher-application-range end of the FM Carbide K-series for this alloy — its austenitic, chromium-carbide-bearing matrix demands more heat and wear resistance than the lighter K05–K15 grades suited to standard ferritic ductile iron.
Ready to cut GGG-NiCr35.3? Shop FM Carbide inserts matched to this alloy's turning, parting, grooving, and milling requirements.
Shop Turning & Grooving Inserts Shop Milling Inserts| Parameter | Value |
|---|---|
| Honing Size | 0.02 – 0.05 mm / 0.001 – 0.002" |
| Rake Angle | Positive (~5° – 11°) |
| Land Angle | Positive / neutral |
| Land Width | 0.10 – 0.20 mm / 0.004 – 0.008" |
A lighter hone and more positive edge than standard cast iron favors clean shearing over the crushing action suited to brittle, easy-to-machine irons — the same logic used for austenitic stainless steel.