Proper Storage and Handling of Carbide Inserts

Indexable insert designations follow ISO 1832 (turning/milling inserts). The ISO code is intentionally compact: the first 4 characters describe the design group (outline, relief/clearance, tolerance class, configuration), and the next 3 pairs (or digits) describe dimensions (size, thickness, corner radius). 

ISO positions (simple)

• 1 — Shape (letter): e.g., C = 80° rhombic (diamond), T = 60° triangle, S = 90° square, R = round. 
• 2 — Clearance (relief) angle (letter): N = 0° (negative), C = 7°, P = 11°, etc. (Positive vs negative affects edge strength and ability to enter tight bores).
• 3 — Tolerance class (letter): e.g., M (molded/pressed, common) or G (ground, tighter). Tolerance affects repeatability when indexing and the height fit in the toolholder.
• 4 — Configuration / cross-section (letter): indicates clamping style, active/ground faces, or chipbreaker family — check the manufacturer’s datasheet for exact features.
• 5 — Size (two digits for ISO metric): cutting edge length or inscribed circle (value set by ISO tables). 
• 6 — Thickness (two digits): corresponds to a standard thickness code (e.g., “04” → 4.76 mm). 
• 7 — Corner radius (two digits): e.g., “08” → 0.8 mm. 

Example: CNMG 120408

• C = 80° rhombic (diamond).
• N = 0° clearance → negative insert (stronger edge; common for roughing).
• M = tolerance class M (press/looser tolerance).
• G = configuration/cross-section (see manufacturer).
• 12 = size (ISO table value; see manufacturer dims).
• 04 = thickness code (≈ 4.76 mm).
• 08 = corner radius (≈ 0.8 mm).
  This is the standard way manufacturers and tool engineers talk about turning and milling inserts — always cross-check the exact shape/feature in the manufacturer datasheet

A. Storage environment (room):

• Keep inserts in a clean, dry, temperature-stable area. Aim for standard indoor storage (room temperature) and relative humidity below ~60% to limit corrosion or packaging degradation. Use climate control/desiccants for long storage.

B. Use original packaging / compartmentalized boxes

• Keep inserts in their original manufacturer trays or compartmented boxes so edges don’t touch. If you transfer packs, use plastic trays with individual compartments or labeled drawer systems. This prevents chipping and makes pick-up faster. 

C. Anti-corrosion packaging when needed

• For long-term storage or humid environments, consider VCI packaging, moisture barrier film, or desiccant sachets. VCI (volatile corrosion inhibitor) film/paper provides an anti-rust atmosphere when sealed. 

D. Labeling & inventory

• Label by ISO code, manufacturer part number, grade/coating, and date received. Use simple bin labels or Tool-Vending systems (like Kennametal’s ToolBOSS) for high-volume shops to control usage and reordering.

E. Handling & PPE

• Avoid touching cutting edges with bare hands — skin oils can contaminate coatings. Use clean gloves or tweezers when handling precision edges. Put a small “do not touch” reminder at pick stations.

F. Organization tips

• Group by operation (turning, milling), by primary material (P = steel, M = stainless), and by grade/coating (PVD/CVD) to avoid picking the wrong insert. Keep a quick-reference sheet at the drawer. 

Coatings (PVD vs CVD):

• PVD (Physical Vapor Deposition): thin (often 1–8 µm), applied at lower temperatures; produces very sharp edges and is excellent for finishing and stainless steels. 
• CVD (Chemical Vapor Deposition): thicker coatings deposited at higher temperatures, often more wear-resistant in heavy cutting and at higher cutting speeds — but CVD layers are thicker and can require a honed edge in some cases. Choose by application (roughing vs finishing) and consult grade tables.
  Chipbreaker geometry (the small ribs/steps on the rake face) controls chip shape and evacuation. These features are often manufacturer-defined and appear as suffixes or chipbreaker codes in the full designation — ISO provides optional positions for chipbreaker descriptions but the exact shape and performance data come from the vendor data sheet. Always preserve the rake face and avoid scratching it; a nicked chipbreaker can produce poor chips or sudden tool wear. 

• Mistake: Storing loose packs where inserts rub together → Fix: compartment trays / original boxes.
• Mistake: Touching cutting edges with oily hands → Fix: gloves / tweezers and wipe edges before use. 
• Mistake: Not cleaning the insert seat → Fix: compressed air and cleaning at every changeover (reduces runout). 
• Mistake: Using wrong grade for material (e.g., CVD where PVD would be better for stainless finish) → Fix: consult grade charts from Sandvik/Kennametal/ISCAR for recommended grades/coatings. 

Good storage and careful handling are low-effort, high-return practices: they preserve geometry, protect coatings, reduce scrap, and keep your machining stable. Follow ISO 1832 to read and catalogue inserts, use manufacturer datasheets for grade/coating choices, store in original or compartmented packs, control humidity, and keep good handling discipline at changeover points. Ready to upgrade your insert management? Explore CNC Tools Depot’s full marketplace of genuine Korloy, Sandvik, Kennametal, Iscar, Widia and more — with OEM part numbers, datasheets, and organized packaging options to simplify storage. (Browse the marketplace to match ISO codes to exact part datasheets and grade recommendations.)

• ISO 1832 — Indexable inserts designation (ISO.org preview). 
• Walter Tools — Designation key in accordance with ISO 1832 (turning).
• MachiningDoctor — ISO inserts: nomenclature, dimensions & tolerances (practical charts). 
• Sandvik Coromant — Metal cutting knowledge & PVD/CVD info. 
• Kennametal — Tooling resources, ToolBOSS inventory solutions, application handbooks. 
• Practical storage & packaging guidance (compartment trays, desiccants, VCI): industry packaging resources and storage guides.