8075B854-01426-Supplemental_ordering_data_to_MIL-DTL-1222J.pdf

Supplemental ordering data to MIL-DTL-1222J for Cobalt alloy MP98T fasteners.

Applicable Document:

MIL-DTL-1222J, General Specification for Studs, Bolts, Screws and Nuts for Applications where a “High Degree of Reliability is required”.

Requirements:

1. COBALT ALLOY COMMERCIAL SPECIFICATION, GRADE, MATERIAL SYMBOL, AND ADDITIONAL

REQUIREMENTS TO CERTIFY ITEMS MEETING COMMERCIAL STANDARDS TO THIS SPECIFICATION:

GRADE FORM MILITARY

CONDITION

STANDARD MATERIAL FASTENER

CONDITION

MATERIAL

SYMBOL

APPLICABLE

PARAGRAPHS

IN MIL-DTL-

1222J

MP98T STUD SOLUTION

ANNEALED

COLD

DRAWN

AND AGED.

AMS 5920 MP98T SOLUTION

ANNEALED

COLD

DRAWN

AND AGED

MP98T 3.1, 3.2.1.1

NOTE: FASTENER MANUFACTURERS MAY PROCURE THIS MATERIAL TO SAE AMS 5919A-13 AND AGE

HARDEN TO MEET THE REQUIREMENTS OF SAE AMS 5920A-13.

2. COBALT ALLOY EXTERNALLY THREADED FASTENERS- Cobalt alloy fasteners shall be fabricated with the following additional requirements:

a. All external threads shall be formed by rolling. External threads shall not be machined or cut or ground.

b. Under head fillet shall be fabricated by cold rolling.

c. Headed fasteners shall be aged after heading.

3. MECHANICAL PROPERTY VALUES FOR COBALT ALLOY BOLTS, STUDS, AND HEX CAP SCREWS

MACHINED SPECIMEN

MATERIAL HEAT

TREATMENT/

CONDITION

NOM. DIA

(INCHES)

TENSILE

STRENGTH,

KSI

YIELD

STRENGTH,

KSI MIN

TENSILE

STRENGT

H, KSI,

MIN

YIELD

STRENGTH,

KSI MIN

ELONGATION IN

4D PERCENT,

MIN

REDUCTION OF AREA,

PERCENT, MIN

MP98T SOLUTION,

ANNEALED,

COLD

DRAWN AND

AGED

ALL SIZES 180-220 150 180 150 15 40

4. For cobalt alloy fasteners, the material symbol, manufacturer’s symbol and the lot number shall be marked on the fasteners ½ inch in diameter or larger. For fasteners less than ½ inch in diameter, only the material symbol shall be marked.

5. For Cobalt alloy materials, MIL-DTL-1222J para 4.2.1 applies.

6. All cobalt alloy (MP98T) fasteners shall be 100% PT inspected per MIL-DTL-1222J para 4.3.3.

7. Wedge tensile test of cobalt alloys. Headed cobalt alloy fasteners shall be wedge tensile tested in accordance with MIL-DTL-1222J para 4.5.2.3. Except that failure is allowed to originate anywhere on the fastener (threaded area, body, head to shank fillet or head), and no fracture may be intergranular in nature.

8. Cobalt alloy bolts, screws and studs shall be inspected IAW ASTM F788-13 DTD 04/01/2013, including supplementary Requirement S1, except that the acid etch required before the inspection for laps shall not be done and the maximum surface discontinuities permitted in S1 shall be 0.25 percent of the nominal diameter.

9. The raw material used for all MP98T fasteners shall be produced by vendors approved by NAVSEA and applicable quality assurance provisions of MIL-DTL-1222J. All MP98T fasteners shall be procured from vendors approved by NAVSEA. Currently SPS Technologies , Jenkintown PA with Timken Latrobe Steel , Latrobe PA as the material supplier are approved.