ISO 5857:2008

Overview

ISO 5857:2008 - "Aerospace - Bolts, with MJ threads, made of alloy steel, strength class 1 250 MPa - Procurement specification" defines the procurement, inspection and quality requirements for aerospace bolts with MJ threads manufactured from alloy steel and rated to strength class 1 250 MPa. It is a procurement specification meant to be invoked whenever referenced in a definition document (e.g., drawing or contract). The standard focuses on characteristics, manufacturing controls and quality assurance to ensure safe, repeatable performance in aerospace applications.

Key topics and technical requirements

• Scope and applicability: Applies to MJ-thread bolts used in aerospace construction; applies when referenced in a definition document.
• Material and strength: Bolts of alloy steel, strength class 1250 MPa; material conformity is verified per the definition document and material standards.
• Dimensions and threads: Dimensional and thread limits follow the definition document and related MJ thread standards; threads must be formed by single rolling after full heat treatment.
• Manufacturing controls:
  • Forging (hot or cold) prior to heat treatment with uniform temperature control for hot forging.
  • Heat treatment rules (limited number of cycles) and stress-relieving after grinding but before thread/fillet rolling.
  • Fillet cold-rolling between head and shank to remove machining marks and produce specified cold work (visual and dimensional checks).
  • Surface roughness and coatings per the definition document and ISO surface texture methods.
• Mechanical tests: Tensile strength and double-shear strength requirements (referenced test methods such as ISO 7961 and ISO 6892); test temperature is ambient unless otherwise stated.
• Quality assurance and inspection:
  • Qualification inspection (e.g., 25 bolts by simple random sampling) and production acceptance inspections per lot.
  • Sampling plans and acceptance criteria (AQL, LQ) consistent with ISO 2859-1.
  • Option to use Statistical Process Control (SPC) in lieu of final sampling if validated and approved.
  • Quality records retention for a minimum of 10 years.

Practical applications and users

ISO 5857:2008 is used by:

• Aerospace fastener manufacturers for production and process control.
• OEMs, suppliers and procurement teams specifying bolt requirements on drawings and contracts.
• Quality, inspection and certification authorities responsible for qualification and lot acceptance.
• Design and structural engineers who require verified mechanical performance data for fastening systems.
• Maintenance/repair organizations sourcing replacement fasteners to meet aerospace traceability and safety requirements.

Keywords: ISO 5857:2008, aerospace bolts, MJ threads, alloy steel bolts, strength class 1250 MPa, procurement specification, quality assurance, sampling plan, heat treatment, tensile strength, statistical process control (SPC).

Related standards

Normative references include: ISO 2859-1, ISO 4288, ISO 5855-2 (MJ threads limits), ISO 6507-1, ISO 6508-1, ISO 6892, ISO 7961, ISO 7966, ISO 7870-1, ISO 8258 and ISO/TR 13425.