Overview
ISO 3551-2:1992 - Rotary core diamond drilling equipment, System A (Inch units) - establishes the official nomenclature and leading dimensions to ensure interchangeability of System A diamond core-drilling components. The standard covers drill rods and couplings; casings and casing accessories (bits, shoes, drive shoes, ream shells); and core recovery gear (core barrels, core bits, core lifters, reaming shells). It specifies equipment characteristics for drilling holes from 1.18 in to 7.88 in and producing cores from 0.73 in to 6.5 in. Inch values in this part are the authoritative figures.
Key topics and technical requirements
- Nomenclature and identification: Standard identification symbols and a system of dimensional identification letters (A, B, C… X, Y) for outside/inside diameters, thread dimensions, lengths, etc.
- Dimensions and tolerances: Detailed dimensional tables (tables 4–57) define O.D./I.D., thread profiles, pitches and critical clearances to achieve interchangeability across manufacturers.
- Materials and mechanical properties: Materials must meet specified mechanical-property requirements (see Table 2) for rods, casings, couplings and related items; alternative materials allowed only by agreement between supplier and purchaser.
- Manufacturing tolerances: Includes eccentricity limits (eccentricity not to exceed 10% of nominal wall thickness), straightness limits (maximum deviation 1 in 1 200 when rolled over a straightedge), and thread conventions (right-hand threads unless otherwise noted).
- Lengths and compatibility: Typical rod and casing lengths in System A (e.g., 120 in, 60 in, 30 in) and guidance where metric lengths may be used in some industries.
Practical applications
- Standardizes component dimensions for manufacturers and suppliers to produce interchangeable diamond drilling equipment.
- Used by mining & exploration companies, geotechnical and civil drilling contractors for specifying and procuring drill strings, casings and core recovery systems.
- Guides design and quality control for OEMs of drill rods, couplings, casing components and core barrels.
- Supports inventory management and field maintenance by ensuring compatibility across brands when operating System A tool strings.
Who should use this standard
- Drill equipment manufacturers and designers
- Procurement and specification engineers in mining, exploration and geotechnical firms
- Drilling contractors, rig operators and maintenance teams
- Standards committees and testing laboratories involved in diamond core drilling equipment
Related standards
- ISO 3552:1992 - Rotary core diamond drilling equipment - System B (Part 2: Inch units) (published in parallel)
- ISO 8866:1991 - Rotary core diamond drilling equipment - System C
- Normative references cited in ISO 3551-2 include ISO 263, ISO 5864, BS 1580 and API 7 among others
Keywords: ISO 3551-2:1992, rotary core diamond drilling equipment, System A, inch units, drill rods, casings, core barrels, interchangeability, dimensions, nomenclature.
