Specification NDBC-5103 Rev.docx

PROCEDURE: NDBC-5103, Rev. -

DATE:

Procurement Specifications for Stainless Steel Chain

NATIONAL DATA BUOY CENTER

JOHN C. STENNIS SPACE CENTER

STENNIS SPACE CENTER, MISSISSIPPI 39529-6000

REVISION HISTORY

ECP P10-0083 New Specification.

ACRONYMS AND ABBREVIATIONS

TERM DEFINITION

NDBC-5103, Rev. -

1.0 PURPOSE

This procedure establishes requirements for the procurement of welded stainless steel chain for use in NDBC mooring applications.

2.0 OBJECTIVE

This procedure assures that the welded stainless steel chain procured commercially conforms to NDBC specifications.

3.0 SCOPE

This procedure applies to chain of the following type: Open link welded, type 316 stainless steel that meets the minimum requirements of NACM “Welded Steel Chain Specifications” and is only of USA origin.

All material in this specification shall be manufactured in the USA unless a wavier is granted by the NDBC Safety, Reliability & Quality Assurance Office. Vendors may request a waiver of this clause prior to the award of the contract but may require additional documentation and or samples prior to granting a waiver.

4.2 Material

The chain material shall be AISI type No. 316 austenitic stainless steel meeting the following composition properties:

4.3 Dimensions

The dimensional requirements for stainless steel open link chain are shown of Table 1. The inside length dimension can be measured either by individual link or by measuring the span of 100 links and dividing by 100. The diameter of the material from which the chain is manufactured shall be the diameter as specified in Table 1 within the following tolerance: -7%, Oversized material is acceptable.

Table 1

4.4 Testing

4.4.1 Proof Load

Each link of chain shall be proof tested to at least the proof test load specified in Table 1. When tested, the chain shall withstand this load without loss of chain integrity. Links or chain segments not withstanding the load shall be removed.

4.4.2 Sampling

For acceptance testing of chain, a lot shall consist of 3000 ft. (1000m) or a fraction thereof of the same grade and size chain. At least one sample for each lot shall be tensile tested. If the original test specimen fails to conform to the breaking force requirements as prescribed in Table 1 for their respective sizes, two additional test specimens from the same lot may be tested. If both additional test specimens conform to the requirements specified, the lot of chain will be considered acceptable.

4.4.3 Tensile Tests

Tensile test to determine breaking force and elongation shall be performed in the following manner and may be performed on the same test specimen. The breaking force test specimen shall consist of a length of chain from any stage of manufacture after hardening and tempering, if applicable, and shall contain at least the number of links in Table 2.

Table 2

4.4.4 Elongation

a. All chain which is heat treated must be in the quenched and tempered condition before elongation is measured.

b. The elongation test specimen shall consist of a length from the lot containing at least the number of links in Table 2 of Section 4.4.3.

c. A positive load not exceeding 10% of the proof test shall be applied for determining the original gauge length (Lo).

d. The elongation shall be based on the total extension at fracture. This is expressed as a percentage of the change in length (L) divided by the original gauge length (Lo). The elongation may be determined by the equation below or by autographic recorder or side scale.

e. Elongation shall not be less than 15% on 316 stainless steel chain.

4.5 Quality

4.5.1 Surface

Chain links shall be free from burrs, flaws, and defects, including rough surfaces.

4.5.2 Marking

Stainless steel chain may be embossed at the option of the manufacturer. Markings shall be embossed using raised characters. Chain links shall not be marked with indented characters.

4.5.3 Finish

Stainless steel chain shall be polished by a suitable chemical or electro-chemical method to produce a bright, clean surface. As an option, the chain may be mechanical polished on equipment with a process that does not allow non-stainless steel particles to be imbedded on the surface of the chain.

5.0 QUALITY ASSURANCE PROVISIONS

5.1 Responsibility For Inspection

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 where such inspections are deemed necessary to assure supplies and services conform to prescribed requirements.

5.2 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 fabrication of the chain.

6.0 PREPARATION FOR DELIVERY

6.1 Preservation and Packaging

Preservation and packaging, which may be the supplier's commercial practice, will be sufficient to afford adequate protection against corrosion, deterioration, and physical damage during shipment from the supply source to the using activity.

6.2 Packing

Packing will be accomplished in a manner that will ensure acceptance by common carrier, at lowest rate, and will afford protection against corrosion or other damage during direct shipment from the supply source to the using activity.

6.3 Shipment Marking

Shipment marking information will be provided on each assembled chain lot and on shipping containers in accordance with the supplier's commercial practice. The information will include nomenclature, contract or order number, contractor's name, and destination.

6.4 Ordering Data

Procurement documents should specify the following:

· Title, number, and date of this specification.

· Chain size and quantity required for delivery.

6.5 DELIVERABLES

Deliverables under this specification will include the following:

· Three copies each of the Certificate of Proof Test, Tensile Test and Elongation Test issued by the chain manufacturer (Section 4.4).

· Verification of Origin. (Section 3.0)

· Three copies of the Material Certification (Section 5.2)

· The chain size and quantity of chain required for delivery.

· Deliver to:

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Microsoft_Excel_97-2003_Worksheet.xls Sheet1

WELDED STAINLESS STEEL CHAIN SPECIFICATIONS

SIZE DIAMETER "A" WORKING LOAD LIMIT (Max.) Proof Test (Min.) Minimum Breaking Force INSIDE LENGTH (Max.) "B" INSIDE WIDTH (Min) "C" APPROX. WEIGHT in mm in mm lbs kg lbs kN lbs kN in mm in mm lbs/ft kg/m

1/2 13 0.512 13.0 5,400 2,449 13,000 58.0 21,600 116.0 1.50 38.1 0.78 19.8 2.00 2.98

5/8 16 0.630 16.0 9,800 4,450 19,600 87.0 39,200 174.0 1.91 48.5 0.90 22.9 3.31 4.92

3/4 20 0.750 20.0 15,000 6,820 30,000 134.0 60,000 268.0 2.75 69.9 1.17 29.7 5.00 7.44

1 26 1.000 26.0 23,250 10,570 46,500 207.0 73,000 414.0 3.53 89.7 1.61 40.9 9.00 13.39

Sheet2

Sheet3 image1.emf image2.png