Specification NDBC-5101 Rev.docx

Procedure:

NDBC-5101, REV. -

NDBC Procurement Specification of Stainless Steel Shackles

CHAIR, ENGINEERING REVIEW BOARD DATE

NATIONAL DATA BUOY CENTER

JOHN C. STENNIS SPACE CENTER

STENNIS SPACE CENTER, MISSISSIPPI 39529-6000

ii

REVISION HISTORY

NDBC-5101, REV. -

NDBC-5101, REV. -

i i ii

ACRONYMS AND ABBREVIATIONS

PURPOSE

This procedure establishes requirements for the procurement of forged, to form by heating and hammering or by a mechanical or hydraulic press, stainless steel shackles of commercial quality for use in NDBC mooring applications.

APPLICATION

This procedure assures forged stainless steel shackles commercially procured conform to NDBC specifications, and specifies the quality assurance provisions unless otherwise specified in the contract or purchase order.

PREREQUISITES

There are no prerequisites associated with this procedure.

DISCUSSION

The procedure establishes requirements and tolerances necessary to ensure stainless steel shackles procured meet the NDBC’s safety, durability and dimensional requirements, and applies to shackles of the following type: safety anchor bolt-type shackle, type 316 stainless steel meeting the requirements of Federal Specification RR-C-271D “Chains and Attachments, Welded and Weldless”, Type IV A.

MATERIALS REQUIRED

None.

SAFETY

None.

INSTRUCTIONS

Materials The chain material shall be AISI type No. 316 austenitic stainless steel meeting the composition properties shown below in Table 1 .

Table 1 - Composition Properties

Form and Dimension The form of the shackle bodies and pins will be similar to that shown in Figure 1 and conform dimensionally to Federal Specification RR-C-271D (Table 2).

Figure 1 – Safety Anchor Bolt-Type Shackle Table 2 – Federal Specification RR-C-271-D Size (D) minimum Diameter Pin (P) minimum Diameter Inside Eye (E) maximum Width between eyes (W) Length inside (L) Nominal tolerance (±) Width Bow (B) Minimum Diameter Outside Eye (R) maximum

Strength

Proof Load Shackles will be capable of withstanding the proof load specified in Table 2 when tested as specified in Section 8.5.1, without developing any surface rupture or defects that would interfere with the serviceability or disassembly of the shackle. After proof loading, shackles will be capable of disassembly by hand.

Breaking Load The minimum breaking load of a shackle assembly when tested as specified in Section 8.5.2 will be as specified in Table 3.

Table 3 – Shackle Assembly Minimum Breaking Load Shackle Size (inches)

Minimum Pounds Minimum Recommended Working Load Limit Pounds

Working Load Limit The recommended working load limit for the shackles covered by this specification is included in Table 3 for information purposes only.

Quality

Surface Shackles shall be free from burrs, flaws, and defects, including rough surfaces. Any surface crack or declivity in excess of ¼ inches any one dimension created during the forging of the shackle is cause for rejection of that shackle.

Remove imperfections less than ¼ inches by grinding with a small diameter stone so sufficient grooming of the affected area matches the surrounding contours. Inability to remove imperfections in this way is cause for rejection of that shackle.

Overall Shackles shall be free from harmful defects such as cracks, seams, pipes, etc. as these may lead to premature failure or otherwise impair or restrict the intended use of the shackle assembly.

Marking Permanently and legibly mark each shackle body with an identifying manufacturer's name or trademark, the recommended safe working load, the shackle body size, and "316” either with raised letters or embossed characters and figures of the maximum practical height permitted by the size of the shackle component being marked, not to exceed 3/4 inches height or 1/8 inches relief. Impression-mark the shackle pin on the head with "316". Ensure marking locations do not interfere with the serviceability of the shackle assembly.

Finish Unless otherwise specified, each shackle shall be passivated using electropolishing in accordance with ASTM A967 “Standard Specification for Chemical Passivation Treatments for Stainless Steel Parts” to produce a bright, clean surface.

Quality Assurance Provisions

Responsibility for Inspection Unless otherwise specified in the contract or purchase order, the supplier is responsible for the performance of all inspection requirements as specified herein. Except as otherwise specified, the supplier may use his/her own facilities or any commercial laboratory acceptable to the Government. The Government reserves the right to perform any of the inspections set forth in the specification to assure supplies and services conform to prescribed requirements.

Material Certification The contractor will furnish a mill physical test either from the manufacturer or a reputable engineering laboratory indicating the composition of the material used in the construction of the shackles.

Sampling

Lot For inspection and testing of shackles, a lot will consist of not less than two and not more than 10,000 shackles made from the same material of the same type and size offered for delivery at one time.

Sampling for Quality Conformance Inspection Select a random sample of shackles from each lot in accordance with Table 4 for the inspection specified in Section 8.4. The Acceptance Number column is the maximum number of defective shackles allowable in a sample size in order for acceptance of the lot. The Rejection Number column is the minimum number of defective shackles in a sample size allowable before rejected.

Table 4 – Sampling for Inspection Number of Shackles in Lot

Sampling for Tests Select a random sample of shackles from each lot in accordance with Table 4 for proof in Section 8.5.

Table 5 – Sampling for Inspection

Quality Conformance Inspection

Examination Exam a random sample of shackles, taken in accordance with Section 5.3.2., to determine form and dimensions, marking, surface, and finish conformance with this specification.

Rejections Reject any lot where the number of defective shackles in the sample is equal to or greater than the rejection number specified in Table 4.

Test

Proof Test Table 5 specifies the number of samples to subject the proof load specified in Table 3 either singly or in series. The diameter of the attachments used in proofing will not be larger than the pin diameter of the shackle under test. Application of the proof load will be at the center of the pin. Maintain the proof load for a minimum of fifteen (15) seconds, release the proof load, disassemble, and examine each shackle to determine conformance as specified in Section 7.3.1.

Rejections If any sample shackle fails to pass the proof test, proof test all shackles in the lot and reject those failing to pass the test. Additionally reject any lot having a material composition varying from that specified in Section 5.0.

Delivery Preparation

Preservation and Packaging Preservation and packaging, which may be the supplier's commercial practice, shall be sufficient to afford adequate protection against corrosion, deterioration, and physical damage during shipment from the supply source to the using activity. Pack in a manner to ensure acceptance by a common carrier, at lowest rate, and protect against corrosion or other damage during direct shipment from the supply source to the using activity.

Marking Provide shipment-marking information, in accordance with the supplier's commercial practice and including nomenclature, contract or order number, contractor’s name, and destination, on each assembled shackle and on shipping containers.

Ordering Data Procurement documents are to specify the following:

Title, number, and date of this specification.

Description of the shackles required (2.0).

Number of assembled shackles for delivery.

Deliverables Deliverables under this specification are to include the following:

Three copies each of the Certified Results of Quality Assurance Provisions as specified in Section 8.0 and delivered to the address on the following page.

National Data Buoy Center ATTN: Contracting Officer Stennis Space Center, MS 39529-6000 The number of assembled shackles as ordered.

image2.wmf image3.png image1.jpeg