4.4Quality assurance

4.4.2.1 General

• a. The supplier shall establish and implement adequate quality control actions and inspections to provide evidence of conformity to the product requirements. NOTE Quality control actions and inspections may be performed by the supplier or by different companies (e.g. manufacturers, test houses and external laboratories) entirely under the supplier’s direct responsibility.
• b. The manufacturer shall have a quality assurance system in place (e.g. ISO 9001).
• c. The supplier shall not use fasteners manufactured more than 10 years before use in space hardware.

NOTE The reasons are possible time‐dependent degradation phenomena (e.g. corrosion, stress corrosion, design modifications, improvements in materials and manufacturing processes).

4.4.2.2 Quality control of materials

• a. Selection and control of suitable materials for fastener fabrication shall be based on the requirements defined in ECSS‐Q‐ST‐70‐71C.
• b. The supplier shall provide evidence that only materials in accordance with the customer specification document for threaded fasteners are used in the fabrication.
• c. The supplier shall issue a raw material certificate (RMC) specifying: material standard designation, heat treatment, form, manufacturer, batch number, batch chemical analysis, batch tensile test results (0,2 % proof stress, ultimate stress and elongation) and batch hardness value.
• d. In the case where NDI is requested in the customer specification document for threaded fasteners, the supplier shall include in the RMC the date of the NDI, name of inspector, NDI results with description of any nonconformance.

4.4.2.3 Sampling procedure

• a. The supplier in agreement with the customer shall determine a sampling procedure in accordance with:

1. ISO 2859‐1 for batch‐by‐batch inspections; or
2. ISO 2859‐2 for isolated batch inspections.

• b. The supplier shall specify the selected sampling procedure in the customer specification document for threaded fasteners by defining a sampling plan.
• c. The supplier shall define the batch acceptability criteria in terms of:

1. acceptance quality limit (AQL), if the batch‐by‐batch inspection method is selected, or
2. limiting quality (LQ), if the isolated batch inspection is selected.

• d. The supplier shall define sample size in terms of inspection levels. NOTE Table C‐ 1 gives the recommended inspection levels, LQ and AQL values to be used.
• e. The supplier shall draw the specified sample units at random from the batch. NOTE A batch of fasteners is a set of fasteners of the same type and diameter, obtained from the same batch of raw material, manufactured by the same process and heat treated as one batch.
• f. The supplier shall accept the batch only if the number of nonconforming units is less or equal to the acceptance level specified in the customer specification document for threaded fasteners.
• g. The supplier shall reject any nonconforming units found during batch inspection.

4.4.2.4 Nonconforming batches

• a. In the case where the number of nonconforming units is greater than the acceptance level specified in the customer specification document for threaded fasteners, the supplier shall reject the batch.
• b. The supplier shall subject re‐submission for inspection of rejected batches to the customer approval.
• c. The customer shall determine the method of acceptance to be applied to re‐submitted batches.
• d. In re‐submitted batches, the supplier shall re‐examine or re‐test all units in the batch.
• e. The supplier shall remove all nonconforming units or replace them by conforming units.
• f. On re‐submission, the supplier shall indicate the nonconforming batches as re‐submitted specifying the cause for previous nonconformance.
• g. The supplier shall subject batches of fasteners for safe‐life applications to NDI in all their units.

4.4.2.5 Product conformance report

• a. The supplier shall issue a product conformance report (PCR), in conformance with the DRD in Annex B, for each delivered batch of fasteners.
• b. The supplier shall deliver the PCR to the customer together with the batch of fasteners.

4.4.2.6 Incoming inspection

• a. On delivery the customer shall carry out an incoming inspection of the batch.
• b. The customer shall establish if the information given in the PCR is complete, clear and satisfactory.
• c. The customer shall verify that the fastener identification marks are consistent with the information given in the PCR.
• d. For structural fasteners with nominal diameters larger than 4 mm (M4) which are not directly procured from a fastener manufacturer (i.e. procured through a distributor or vendor), the customer shall carry out: dimensional check, tensile test, chemical analysis, hardness test and non‐destructive inspections in accordance with 4.2.4.

NOTE A structural fastener is a fastener used in either the primary or secondary load path of a structure.

• e. Sampling procedure shall be in accordance with 4.4.2.3.
• f. Only qualified test laboratories shall carry out the tests.
• g. The supplier shall provide evidence that the batch conforms to the customer specifications.

A (normative)

Customer specification document for threaded fasteners – DRD

A.1 DRD identification A.1.1 Requirement identification and source document

This DRD is called from ECSS‐Q‐ST‐70‐46, requirement 4.1.1a.

A.1.2 Purpose and objective

Within the contractual relation between the customer and the supplier, the customer specification document for threaded fasteners specifies the technical and quality requirements, and the criteria and procedures to be used to assess the fulfilment of such requirements. The customer specification document for threaded fasteners is prepared by the customer, who sets the technical and quality requirements, in collaboration with the supplier, who agrees to the requirements and procedures.

This DRD does not define format, presentation or delivery requirements of the customer specification document for threaded fasteners.

A.2 Expected response A.2.1 Scope and contents <1> Specifications

• a. The document shall specify the following items:

1. The selected raw material in terms of: standard designation, heat treatment, form, minimum mechanical properties (hardness, 0,2 % proof stress, UTS, elongation and toughness).

2. The complete fastener manufacturing process in terms of all the single operations required from the raw material to obtain the finished product.

3. The nominal dimension, tolerance and geometry of the finished fastener.

4. Indication of fastener designation and thread type.

5. Technical drawings enclosed to the customer specification document for threaded fasteners.

6. Surface treatment of finished fasteners.

7. Minimum hardness values of finished fasteners.

8. Tensile mechanical properties of finished fasteners in terms of: load to yield, ultimate load and elongation to failure.

9. Minimum shear load to failure of finished fasteners.

10. Minimum and mean required fatigue strength of finished fasteners in terms of stress range versus fatigue cycles (S‐N curves) at specified constant stress ratios.

11. Minimum creep properties of finished fasteners in terms of elongation, reduction of area and time to failure.

12. Corrosion requirements in terms of exposure time and acceptability criteria (maximum number and density of corrosion pits).

13. Stress-corrosion testing if requested.

14. Definition of mechanical test methods and conditions for e. f. g. h. i. j. and k. in accordance with the relevant clauses of this Standard and other applicable standards.

15. Quality control plan in terms of: identification marking, sampling procedure, sampling plan and non‐destructive inspection (NDI) plan.

16. Definition of procedures and time schedule for handling, storage, transportation and delivery.

A.2.2 Special remarks

None.

B (normative)

Product conformance report (PCR) – DRD

B.1 DRD identification B.1.1 Requirement identification and source document

This DRD is called from ECSS‐Q‐ST‐70‐46, requirement 4.4.2.5a.

B.1.2 Purpose and objective

This DRD defines the contents of the PCR.

B.2 Expected response B.2.1 Scope and contents <1> Contents

• a. The PCR shall indicate:

1. batch supplier name/code;

2. date of batch manufacturing;

3. purchase order form;

4. raw or semi‐finished material supplier name/code;

5. date of raw or semi‐finished material production;

6. batch identification number and fastener identification marks;

7. reference to fastener specifications;

8. the raw material certificate (RMC) including a report of quality the inspections (destructive and non‐destructive) carried out on the raw or semi‐finished material as specified in this document;

9. report of the fasteners quality control inspections (destructive and non‐destructive) as specified in this document;

10. report of conformance/nonconformance and corrective actions;

11. any other relevant documentation.

B.2.2 Special remarks

None.

C (informative)

Inspection levels, acceptance quality limits (AQL) and limiting quality levels (LQ) for inspection of fasteners

Table C- 1: Inspection levels, acceptance quality limits (AQL) and limiting quality levels (LQ) for inspection of fasteners

Figure description:

Text: E CSS Font: Italicized serif Design: Parallelogram-shaped frame divided into two sections. The letter "E" is in purple on a white background. The letters "CSS" are in white on a purple background.

(*) Test carried out on customer request.

Bibliography

ECSS system – Description, implementation and general requirements