Overview
ISO 10888:1999 specifies dimensional characteristics, mounting types and concentricity tolerance requirements for keyless three‑jaw drill chucks. It covers both self‑tightening and hand‑tightening keyless chucks with taper or internal thread (inch) mounts and defines three usage classes: Heavy (H), Medium (M) and Light (L). The standard also prescribes designation and marking rules to ensure clear product identification.
Key topics and technical requirements
- Scope and classes: Defines three classes (H, M, L) for machine‑tool, light industrial and DIY/portable tool applications.
- Mount types and dimensions: Includes detailed overall dimensions for taper mounts (Morse and Jacobs tapers) and internal inch‑thread mounts, with capacity ranges for each class.
- Concentricity tolerances (Full Indicator Movement, FIM): Specifies how to measure spindle runout using test mandrels at defined distances. Typical tolerance examples:
- Self‑tightening chucks: Class H (taper) FIM = 0.20 mm; Class M (taper) FIM = 0.25 mm; Class M (thread) FIM = 0.30 mm; Class L (thread) FIM = 0.35 mm.
- Hand‑tightening chucks (portable tools): Class H (thread) FIM = 0.30 mm; Class M (thread) FIM = 0.35 mm; Class L (thread) FIM = 0.40 mm.
- Designation rules: Standardized naming convention (e.g., “Self‑tightening keyless chuck ISO 10888 - T - B10 - 6,5H”) to indicate mount type, taper/thread size, capacity and class.
- Marking requirements: Chucks must be permanently marked with the manufacturer/model, capacity range and taper symbol or thread designation; packaging may also identify origin.
Applications and who uses it
ISO 10888 is used by:
- Chuck manufacturers for design, production and quality control of keyless three‑jaw chucks.
- Machine tool and portable power tool OEMs to specify compatible chucks (taper vs thread mount).
- Procurement and specification engineers selecting chucks by class (H/M/L), capacity and runout tolerance.
- Metrology and test laboratories performing concentricity (FIM) checks and compliance testing.
- Tooling distributors and maintenance teams ensuring interchangeability and safe use on drills, drill presses and portable drivers.
Practical benefits include consistent interchangeability, predictable runout performance, and clear product labelling-critical for precision drilling and repeatable manufacturing processes.
Related standards
Keywords: ISO 10888, keyless three‑jaw drill chucks, self‑tightening chuck, hand‑tightening chuck, concentricity tolerance, Full Indicator Movement, taper mount, internal thread mount, drill chuck specification.