Search and compare carbide insert grades across Sandvik, Kennametal, Kyocera, Iscar, Mitsubishi, Sumitomo, and Walter. Find equivalent grades for ISO P/M/K/S applications.
| ISO | Sandvik Coromant | Kennametal | Kyocera | Iscar | Mitsubishi | Sumitomo | Walter |
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Carbide insert grades are classified under ISO 513:2012 into color-coded application groups. This international standard defines six main groups β P (steel, blue), M (stainless steel, yellow), K (cast iron, red), N (non-ferrous, green), S (superalloys, brown), and H (hardened, gray). The grade cross-reference tool above focuses on the four most commonly sourced groups: P, M, K, and S β covering approximately 85% of all machining applications in general engineering, automotive, aerospace, and medical device manufacturing.
Each ISO group specifies not only the workpiece material but also the expected failure mode and wear mechanism. P-grade tools wear primarily by cratering and thermal deformation; M-grade tools fail by notching and built-up edge; K-grade tools by abrasive flank wear; S-grade tools by plastic deformation and edge chipping. A cross-reference search that ignores these fundamental differences can lead to catastrophic tool failure, which is why our grade matching prioritizes ISO group compatibility above brand equivalence.
ISO P covers unalloyed and alloyed steels, from mild 1018 to hardened 4140 and 8620. Steel machining generates long, ductile chips and high cutting temperatures (600-900Β°C at the tool-chip interface). Grades in this group require substrates with high thermal conductivity and coatings that resist crater wear. Sandvik's GC4325, Kennametal's KCU10, and Mitsubishi's UE6020 are all optimized for steel turning with medium to roughing conditions. The key parameter when cross-referencing P-grade tools is thermal stability β a grade rated for continuous cutting in steel may fail immediately in interrupted cuts.
Stainless steels (304, 316, 17-4 PH, duplex) are the most challenging group because they combine high work-hardening rates with low thermal conductivity. M-grade inserts must resist built-up edge formation at low cutting speeds and plastic deformation at high speeds. Grades like Iscar IC8300, Kyocera CA125M, and Walter WSM35S use specialized substrate grain structures (0.2-0.5 ΞΌm) with moderate coating thickness (8-12 ΞΌm) to balance edge sharpness with wear resistance. When cross-referencing M-grade tools, prioritize edge toughness β a harder grade that performs well in P applications may chip immediately in stainless due to notching at the depth-of-cut line.
Gray and ductile irons (GG25, GGG40, GGG70) produce short, segmented chips and generate abrasive wear on the tool flank. K-grade inserts need high hardness substrates with thick, abrasion-resistant coatings. Sandvik GC3215, Kennametal KCK20B, and Sumitomo AC300K are benchmark grades for gray iron turning at high speeds (400-700 SFM). Cast iron's graphite content acts as a natural lubricant, allowing higher cutting speeds than steel grades. The critical cross-reference parameter for K-group is coating adhesion β delamination under the abrasive wear mode is a common failure with low-quality substitute grades.
Nickel-based superalloys (Inconel 718, Waspaloy, Hastelloy) and titanium alloys (Ti-6Al-4V, Ti-5553) represent the extreme edge of machining difficulty. These materials retain high strength at elevated temperatures (up to 1000Β°C), generating extreme cutting forces and rapid flank wear. S-grade inserts require tough, fine-grain substrates with AlTiN or TiSiN coatings that maintain oxidation resistance above 800Β°C. Kennametal KCS10, Mitsubishi MP9120, and Sandvik GC1105 are specifically engineered for this application. When cross-referencing S-grade tools, hot hardness retention is the most critical parameter β a grade that performs well in titanium at low SFM may deform plastically in Inconel at the same cutting speed.
A grade cross-reference that ignores coating type is incomplete. CVD (Chemical Vapor Deposition) coatings β typically AlβOβ + TiCN multilayers β are 10-20 ΞΌm thick and provide superior crater wear resistance at high cutting speeds. They are preferred for steel and cast iron turning at speeds above 300 SFM. PVD (Physical Vapor Deposition) coatings β AlTiN, TiSiN, AlCrN β are 2-6 ΞΌm thick with compressive residual stress, offering better edge toughness and resistance to edge chipping. PVD-coated grades dominate in stainless steel, superalloys, and any interrupted cut application.
When substituting a grade from a different brand, matching the coating technology is often more important than matching the ISO group. A CVD-coated P-grade insert from one brand is NOT a direct substitute for a PVD-coated P-grade insert from another β they are designed for fundamentally different cutting conditions. Use this cross-reference tool as a starting point, then verify coating type and recommended cutting speed range before committing to a substitution.
An often-overlooked factor in grade selection is the cutting condition type. Continuous turning (uniform OD cuts on bar stock) allows the use of harder, more wear-resistant grades with higher AlβOβ content in the CVD coating. Interrupted cuts (face milling with entry/exit impacts, turning with keyways, scale on forged surfaces) require tougher substrates with higher cobalt content and PVD coatings that resist micro-cracking.
The same ISO P application group can require completely different grades depending on interruption frequency. For continuous steel turning, Sandvik GC4325 (CVD, medium-hard substrate) is ideal. For heavily interrupted steel cuts, Sandvik GC3330 (PVD, tougher substrate) would be preferred. A direct cross-reference without considering this distinction would recommend the wrong tool. This is why experienced buyers maintain dual-grade inventory β a harder grade for roughing and a tougher grade for interrupted or finishing operations.
How reliable are grade cross-references between brands? Cross-references provide a starting point, but grades from different manufacturers are never identical. Variations in substrate grain size (0.2 ΞΌm vs 0.8 ΞΌm), cobalt content (6% vs 12%), coating adhesion, and edge preparation (honing radius) mean two "equivalent" grades can perform very differently in the same operation. Always validate with a trial batch before committing to large-scale substitution.
Does coating thickness affect grade interchangeability? Yes. CVD coatings (10-20 ΞΌm) are ideal for high-speed continuous cutting but can cause edge chipping in interrupted operations. PVD coatings (2-6 ΞΌm) provide better edge toughness. When cross-referencing, match the original coating type first, then the substrate grade. A PVD grade cannot replace a CVD grade in high-speed steel turning without significant performance loss.
How can I test a substitute grade at low cost? Request 5-10 pieces of the proposed substitute grade and run a controlled comparison. Machine 50 parts with the current grade and 50 parts with the substitute, measuring tool wear at regular intervals. Compare tool life, surface finish (Ra), and power consumption. Most reputable suppliers offer sample programs β request free samples here.
What does the first letter in a grade name mean? Most manufacturers encode the ISO group in the grade name. Sandvik's "GC4325" β the G indicates a coated grade; Iscar's "IC8300" β IC stands for Iscar Carbide; Kennametal's "KCU10" β K is Kennametal, C is coated. The numbers typically indicate the hardness/wear resistance balance within the brand's own classification system. These internal codes cannot be cross-interpreted between brands β only the ISO application group and coating type provide valid comparison points.
Can I use a P-grade insert for stainless steel in an emergency? Not recommended. P-grade inserts lack the edge toughness and notching resistance required for stainless steel's work-hardening behavior. An M-grade insert used in steel will wear faster but may still function. A P-grade insert used in stainless risks immediate chipping and potential tool holder damage. Emergency substitutions should only be made at reduced cutting speeds (50-60% of normal) and reduced feed rates.
How do I know if a substitute grade is truly equivalent? Compare four parameters: ISO application group (must match), coating type (CVD vs PVD β ideally match), hardness/ wear resistance position within the brand's own range (a "roughing" grade should replace another "roughing" grade), and recommended cutting speed range (should overlap within 15%). The table above groups grades by ISO class and wear resistance level to facilitate this comparison.
What causes inconsistent performance between two supposedly equivalent grades? Most common causes: substrate grain size difference (affects edge sharpness and toughness), coating thickness variation (affects crater resistance and edge integrity), edge preparation radius difference (affects cutting forces and surface finish), and differences in the post-coating treatment (some brands apply surface finishing that improves chip flow). These parameters are rarely published in public datasheets, which is why trial testing is essential.
Is it worth paying more for branded grades vs. generic Chinese substitutes? Branded grades from Sandvik, Kennametal, and Mitsubishi offer verified consistency across batches, published technical data, and application engineering support. Generic Chinese manufacturers can produce acceptable quality at 40-60% lower cost, but batch-to-batch consistency varies significantly. For high-volume production where a tool failure stops a production line, branded grades offer lower total cost. For maintenance, repair, and operations (MRO) with less stringent quality requirements, cost-effective alternatives may be suitable. Carbide Tooling provides both options with full ISO quality documentation.