Overview
ISO 6987:2012 specifies the dimensions of indexable hard material inserts with rounded corners and a partly cylindrical fixing hole. These standardized inserts are primarily used on turning and boring tools and are intended to be mounted with a countersunk-head screw or alternative fixing elements (for example, pin locks). The standard ensures interchangeability, consistent marking, and defined measurement methods for a wide range of insert shapes and sizes.
Key topics and technical requirements
- Insert types covered: TC, TP (triangular); SC, SP (square); CC, CP, DC, VB, VC (rhombic with various included angles); RC, RP (round); WC (hexagonal/trigon). Variants with and without chip breakers are included.
- Fixing hole geometry: The fixing hole is partly cylindrical. The cylindrical diameter is denoted d and tabulated. Positioning dimensions t and c must satisfy:
- 0.05 d ≤ t ≤ 0.3 d
- 0.15 d ≤ c ≤ 0.3 d
These ranges cover inserts whose upper faces are below, level with, or above the cutting edges.
- Screw compatibility: Profiles must allow countersunk screws with head taper angles between 40° and 60°. The tangent theoretical taper at point P shall satisfy ϕ ≥ 65°.
- Interchangeability and tolerances: Inserts are supplied in tolerance class M, and VC-shape inserts may also be in class G, per ISO 1832. Annex A provides tolerance extracts; recommended dimensions and preferred size ranges are given in the main tables.
- Chip breakers: Inserts may have standardized face chip breakers (designated “T”) or be without chip breakers (“W”). Chip breaker shape and dimensions are not standardized and must be specified where necessary.
- Designation, marking and measurement:
- Designation follows ISO 1832.
- Marking should show at least the group-of-application symbol (ISO 513) or the commercial grade designation.
- Annex B specifies methods for measuring dimension m.
Applications and users
- Who uses ISO 6987:2012:
- Cutting-tool designers and manufacturers
- Toolroom engineers and suppliers of indexable inserts
- Machine shops and OEMs specifying compatible turning and boring inserts
- Quality and inspection teams verifying insert interchangeability
- Practical value:
- Ensures mechanical interchangeability of inserts across toolholders
- Reduces tooling design ambiguity when specifying fixing-hole geometry and tolerances
- Improves procurement consistency and reduces inventory complexity by using recommended standard sizes
Related standards
- ISO 1832 - Indexable inserts designation and tolerances (referenced for tolerance classes and designation rules)
- ISO 513 - Classification and application of hard cutting materials (group-of-application symbols)
- Prepared by ISO/TC 29/SC 9 (tools with cutting edges made of hard materials)
Keywords: ISO 6987:2012, indexable hard material inserts, fixing hole dimensions, rounded corners, turning and boring tools, countersunk head screw, insert tolerances, ISO 1832, ISO 513.
Open preview (PDF)Indexable hard material inserts with rounded corners, with partly cylindrical fixing hole — Dimensions
