ISO 4205:2016

Overview

ISO 4205:2016 specifies the dimensions and tolerances (in millimetres) for 90° countersinks with parallel shanks and solid pilots for general use. This third edition (2016) is a minor revision of the earlier edition and adds an informative annex that maps the standard’s designations to the ISO 13399 cutting‑tool data model. The standard provides diagrammatic geometry (Figure 1) and a table of dimensional ranges and associated tolerances for commonly used cutting diameters.

Key topics and requirements

• Scope and intent: Defines the geometric parameters and tolerance classes for 90° countersinks intended for general machining applications.
• Dimensional data: Cutting diameter categories (e.g., 2 ≤ d ≤ 3.15 up to 12.5 < d ≤ 20) with specified pilot and shank diameters and relevant lengths; tolerances are given per the nominal size ranges.
• Tolerancing reference: Uses ISO 286-2 for tolerance classes and limit deviations on linear sizes (holes and shafts).
• Design notation and data exchange: Annex A provides a direct relationship between ISO 4205 designations (cutting diameter, guide pilot diameter, connection/shank diameter, overall length, etc.) and ISO 13399 property symbols (e.g., DC, GPD, DCONMS, OAL, LS, GPL, SIG).
• Illustrative figure: Figure 1 is provided as a diagrammatic guide to the dimensions (note: figure is illustrative and not a detailed design drawing).

Applications and who uses it

ISO 4205:2016 is applicable across machining, tooling and manufacturing sectors where standardized countersinks are required. Typical users include:

• Tool manufacturers producing 90° countersinks with parallel shanks and solid pilots
• CNC programming and tooling engineers who specify cutting tools and ensure interchangeability
• Procurement and quality teams validating delivered tooling to standard dimensions and tolerances
• CAD/CAM and tooling data specialists leveraging ISO 13399 for tool data representation and exchange
• Machine shops and metalworking professionals using countersinks for fastener seating, chamfering and hole preparation

Related standards

• ISO 286-2 - Tolerance classes and limit deviations for holes and shafts (referenced for tolerancing)
• ISO 4206 - Counterbores with parallel shanks and solid pilots (related tooling family)
• ISO 13399 (all parts) - Cutting tool data representation and exchange (Annex A maps ISO 4205 designations to ISO 13399 symbols)

ISO 4205:2016 ensures consistent dimensions and tolerances for 90° countersinks, enabling interchangeability, clearer procurement specifications, and seamless integration with tooling data systems.