ISO 6987:2012

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.