MS27039 : Mil-Spec Hardware
MS27039 : Mil-Spec Hardware Specification
SCREW, MACHINE - PAN HEAD, STRUCTURAL,
CROSS RECESSED
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REQUIREMENTS:
NOTES:
- 1. All dimensions are in inches.
- 2. Screws shall be free from burrs and sharp edges.
- 3. Dimensions are to be met after plating.
- 4. Shank diameter may be .001 oversize for a maximum distance of .031 adjacent to the head.
- 5. In the event a conflict between the text of this document and the references cited herein, the text of
- this document will take precedence.
- 6. Unless otherwise specified, issues of referenced documents are those in effect at the time of solicitation.
- 7. Caution should be taken during plating process. The contractor shall be responsible for the safe
- reutilization and disposal of all materials generated by this process in accordance with ASTM A380,
- section 8.2 and 8.7.
- 8. Items manufactured to Rev. C and Rev. D may be delivered from suppliers stock until depletion.
REQUIREMENTS:
1. MATERIAL:
- Aluminum Alloy 2024 (UNS A92024) in accordance with QQ-A-430, Temper 2024-D, or
QQ-A-225/6, Temper T4.
- Manganese Bronze (UNS C67000) in accordance with ASTM B138.
- Alloy Steel 8630 (UNS G86300) in accordance with MIL-S-7839, 26-32 HRC or 8740
(UNS G87400), 4130 (UNS G41300) in accordance with MIL-S-6049.
- Heat and Corrosion-Resistant Steel, A286 Iron Base Super Alloy (UNS S66286) in
accordance with AMS 5731 or AMS 5732.
2. PROTECTIVE COATING AND SURFACE TREATMENT:
- Aluminum Alloy: Anodize, in accordance with MIL-A-8625, Type I or II.
- Manganese Bronze: Cadmium Plate, in accordance with QQ-P-416, Type II, Class 3.
- Manganese Bronze: uncoated.
- Alloy Steel: Cadmium Plate, in accordance with QQ-P-416, Type II, Class 2.
- Heat and Corrosion-Resistant Steel: Passivate in accordance with QQ-P-35 after removal
of all oil and grease. Passivation verification test per Method 102 of MIL-STD-753.
3. TENSILE STRENGTH:
- Aluminum Alloy: 62,000 psi min ultimate tensile strength.
- Manganese Bronze: 85,000 psi min ultimate tensile strength.
- Alloy Steel: 125,000 to 145,000 psi ultimate tensile strength.
- Heat and Corrosion-Resistant Steel: 130,000 psi min ultimate tensile strength.
4. THREADS:
Threads shall be accordance with FED-STD-H28/2. Acceptability of screw threads shall
be in accordance with FED-STD-H28/20, system 21.
5. RECESS:
The recess shall be in accordance with MS9006.
6. MATERIAL AND FINISH CODE:
- Add DD before dash number for Anodized Aluminum Alloy Screw.
- Add BP before dash number for Cadmium Plated Manganese Screw.
- Add B before dash number for uncoated Manganese Bronze Screw.
- Add - before dash number for Cadmium Plated Alloy Steel Screw.
- Add C before dash number for Heat and Corrosion-Resistant Steel Screw.
7. PART NUMBER:
The part number shall consist of the basic MS number followed by the material and finish code
followed by the dash number.
- Example: MS27039DD0809 indicates - Screw, Machine - Pan Head Structural, Cross Recessed;
.164-32 UNC-3A, .594 length, Anodized Aluminum
Alloy Screw.
- MS27039BP 0809 indicates - Screw, Machine - Pan Head Structural, Cross Recessed;
.164-32 UNC-3A, .594 length, Cadmium Plated
Manganese Screw.
- MS27039B0809 indicates - Screw, Machine - Pan Head Structural, Cross Recessed;
.164-32 UNC-3A, .594 length, uncoated Manganese
Bronze Screw.
- MS27039 - 0809 indicates - Screw, Machine - Pan Head Structural, Cross Recessed;
.164-32 UNC-3A, .594 length, Cadmium Plated Alloy
Steel Screw.
- MS27039C0809 indicates - Screw, Machine - Pan Head Structural, Cross Recessed;
.164-32 UNC-3A, .594 length, Heat and Corrosion-
Resistant Steel Screw.
8. HEAD MARKING:
- a. Basic part no. and applicable dash no. (Basic part optional for .164-32 screw sizes).
- b. Material as follows: Aluminum Alloy - none, Bronze - “B”, Alloy Steel - “-”, Heat and Corrosion - Resistant Steel -”C”.
- c. Manufacturer’s trade-mark shall be added, location optional.
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