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MS51957 screw — pan

Screw, Machine, Pan Head, Cross-Recessed, Corrosion Resistant Steel, UNC-2A, from MS51957 Rev. D w/ Amendment 1. Every row below is transcribed from the standard and has its own link.

MS51957 at a glance

MS51957, screw, machine, pan head, cross-recessed, corrosion resistant steel, unc-2a
MS51957
MS51957 engineering drawing with dimensions
Engineering drawing · dimensions in inches

Specification

ItemValue
Headpan
Drivecross-recess (NASM9006)
Thread seriescoarse (UNC-2A)
MaterialAustenitic corrosion resistant steel Type 302, 304, 304L, 305, 316, 316L, 384 or XM-7 per SAE-AMS-QQ-S-763 (UNS S30200, S30400, S30403, S30500, S31600, S31603, S38400, S30430).
Heat treatmentMinimum tensile strength 80,000 psi (load per Table I); yield strength (0.2 percent offset) 30,000 psi minimum.
ItemValue
FinishPassivate per SAE-AMS2700, or black oxide MIL-DTL-13924 Class 4 (not for Type 316 or 316L).
ProcurementFF-S-92
Thread specificationFED-STD-H28/2
StatusRev. D (20 Apr 2011) with Amendment 1. Notice 1 (24 Oct 2016): validated for use in acquisition. Supersedes MS51957C (25 Apr 1997); screws made before 25 Apr 1997 may be used until stock is depleted.

Dimensions by size

Dimension, in.0860-56 UNC-2A.1120-40 UNC-2A.1380-32 UNC-2A.1640-32 UNC-2A.1900-24 UNC-2A.2500-20 UNC-2A.3125-18 UNC-2A.3750-16 UNC-2A
D1 body dia.0717 – .0860.0925 – .1120.1141 – .1380.1399 – .1640.1586 – .1900.2127 – .2500.2712 – .3125.3287 – .3750
A head dia.1550 – .1670.2050 – .2190.2560 – .2700.3060 – .3220.3570 – .3730.4730 – .4920.5940 – .6150.7160 – .7400
H head height.0530 – .0620.0700 – .0800.0870 – .0970.1050 – .1150.1220 – .1330.1620 – .1750.2030 – .2180.2440 – .2610
P head radius ref.0100.0100.0150.0150.0200.0350.0400.0400
R fillet max.0130.0170.0210.0250.0290.0380.0470.0560
driver size11222344
min tensile lbf30048073011201400254041906200

Minimum – maximum as tabulated in MS51957 Rev. D w/ Amendment 1; letters as on the standard's drawing.

Part numbers and lengths

Every part number of MS51957 Rev. D w/ Amendment 1, by thread size, each with its own link.

.0860-56 UNC-2A12 part numbers · tolerance +0/-.031

Part no.Length, in
MS51957-1.125
MS51957-2.188
MS51957-3.250
MS51957-4.312
MS51957-5.375
MS51957-6.438
MS51957-7.500
MS51957-8.625
MS51957-9.750
MS51957-10.875
MS51957-141.562
MS51957-1421.000

.1120-40 UNC-2A16 part numbers

Part no.Length, inTol.
MS51957-11.125+0/-.031
MS51957-12.188+0/-.031
MS51957-13.250+0/-.031
MS51957-14.312+0/-.031
MS51957-15.375+0/-.031
MS51957-16.438+0/-.031
MS51957-17.500+0/-.031
MS51957-18.625+0/-.031
MS51957-19.750+0/-.031
MS51957-20.875+0/-.031
MS51957-211.000+0/-.031
MS51957-221.250+0/-.062
MS51957-231.500+0/-.062
MS51957-120.562+0/-.031
MS51957-1211.125+0/-.062
MS51957-1221.375+0/-.062

.1380-32 UNC-2A18 part numbers

Part no.Length, inTol.
MS51957-24.125+0/-.031
MS51957-25.188+0/-.031
MS51957-26.250+0/-.031
MS51957-27.312+0/-.031
MS51957-28.375+0/-.031
MS51957-29.438+0/-.031
MS51957-30.500+0/-.031
MS51957-31.625+0/-.031
MS51957-32.750+0/-.031
MS51957-33.875+0/-.031
MS51957-341.000+0/-.031
MS51957-351.250+0/-.062
MS51957-361.500+0/-.062
MS51957-371.750+0/-.062
MS51957-382.000+0/-.062
MS51957-123.562+0/-.031
MS51957-1241.125+0/-.062
MS51957-1251.375+0/-.062

.1640-32 UNC-2A22 part numbers

Part no.Length, inTol.
MS51957-39.125+0/-.031
MS51957-40.188+0/-.031
MS51957-41.250+0/-.031
MS51957-42.312+0/-.031
MS51957-43.375+0/-.031
MS51957-44.438+0/-.031
MS51957-45.500+0/-.031
MS51957-46.625+0/-.031
MS51957-47.750+0/-.031
MS51957-48.875+0/-.031
MS51957-491.000+0/-.031
MS51957-501.250+0/-.062
MS51957-511.500+0/-.062
MS51957-521.750+0/-.062
MS51957-532.000+0/-.062
MS51957-542.250+0/-.094
MS51957-552.500+0/-.094
MS51957-562.750+0/-.094
MS51957-573.000+0/-.094
MS51957-126.562+0/-.031
MS51957-1271.125+0/-.062
MS51957-1281.375+0/-.062

.1900-24 UNC-2A21 part numbers

Part no.Length, inTol.
MS51957-58.188+0/-.031
MS51957-59.250+0/-.031
MS51957-60.312+0/-.031
MS51957-61.375+0/-.031
MS51957-62.438+0/-.031
MS51957-63.500+0/-.031
MS51957-64.625+0/-.031
MS51957-65.750+0/-.031
MS51957-66.875+0/-.031
MS51957-671.000+0/-.031
MS51957-681.250+0/-.062
MS51957-691.500+0/-.062
MS51957-701.750+0/-.062
MS51957-712.000+0/-.062
MS51957-722.250+0/-.094
MS51957-732.500+0/-.094
MS51957-742.750+0/-.094
MS51957-753.000+0/-.094
MS51957-129.562+0/-.031
MS51957-1301.125+0/-.062
MS51957-1311.375+0/-.062

.2500-20 UNC-2A19 part numbers

Part no.Length, inTol.
MS51957-76.312+0/-.031
MS51957-77.375+0/-.031
MS51957-78.438+0/-.031
MS51957-79.500+0/-.031
MS51957-80.625+0/-.031
MS51957-81.750+0/-.031
MS51957-82.875+0/-.031
MS51957-831.000+0/-.031
MS51957-841.250+0/-.062
MS51957-851.500+0/-.062
MS51957-861.750+0/-.062
MS51957-872.000+0/-.062
MS51957-882.250+0/-.094
MS51957-892.500+0/-.094
MS51957-902.750+0/-.094
MS51957-913.000+0/-.094
MS51957-132.562+0/-.031
MS51957-1331.125+0/-.062
MS51957-1341.375+0/-.062

.3125-18 UNC-2A18 part numbers

Part no.Length, inTol.
MS51957-92.375+0/-.031
MS51957-93.438+0/-.031
MS51957-94.500+0/-.031
MS51957-95.625+0/-.031
MS51957-96.750+0/-.031
MS51957-97.875+0/-.031
MS51957-981.000+0/-.031
MS51957-991.250+0/-.062
MS51957-1001.500+0/-.062
MS51957-1011.750+0/-.062
MS51957-1022.000+0/-.062
MS51957-1032.250+0/-.094
MS51957-1042.500+0/-.094
MS51957-1052.750+0/-.094
MS51957-1063.000+0/-.094
MS51957-135.562+0/-.031
MS51957-1361.125+0/-.062
MS51957-1371.375+0/-.062

.3750-16 UNC-2A16 part numbers

Part no.Length, inTol.
MS51957-107.500+0/-.031
MS51957-108.625+0/-.031
MS51957-109.750+0/-.031
MS51957-110.875+0/-.031
MS51957-1111.000+0/-.031
MS51957-1121.250+0/-.062
MS51957-1131.500+0/-.062
MS51957-1141.750+0/-.062
MS51957-1152.000+0/-.062
MS51957-1162.250+0/-.094
MS51957-1172.500+0/-.094
MS51957-1182.750+0/-.094
MS51957-1193.000+0/-.094
MS51957-138.562+0/-.031
MS51957-1391.125+0/-.062
MS51957-1401.375+0/-.062

Part number

How a MS51957 part number is built, segment by segment

What each code means

PartMeaning
FormatMS51957-<dash number>[S316][B]
ExampleMS51957-1 = .0860-56 UNC-2A, .125 long, passivated; MS51957-1B = black oxide; MS51957-1S316 = Type 316/316L, passivated
Length tolerance, .125 to 1.000+0/-.031
Length tolerance, 1.125 to 2.000+0/-.062
Length tolerance, 2.250 to 3.000+0/-.094
DashDash number from Table I selects thread size and length (1 to 142)
(none)Material: any 300 series austenitic CRES listed in the material requirement
S316Material: Type 316 or 316L (marked "316" on head, sizes #10 and larger)
(none)Finish: passivated
BFinish: black oxide coated (not available for Type 316/316L)

Notes from the standard

  • Thread: Unified external class 2A UNC, FED-STD-H28/2; threads extend to within two threads of the head bearing surface; lengths over 2.000 have 1.750 minimum complete thread.
  • Recess per NASM9006. Magnetic permeability when specified: below 2.0 (air = 1.0) at H = 200 oersteds.
  • Dash numbers 120 to 142 (lengths .562, 1.125, 1.375 and 1.000 for .0860) are inactive for new design after 18 July 1986. Dash numbers 22, 58, 74, 75, 90, 91, 105 and 106 are manufacturer non-stock production items.
  • The length tolerance bands (+0/-.031, -.062, -.094) are placed by position of the printed labels in the table.
  • Sheet 5 (Table II) cross-references the canceled MS16200, MS35233, MS35216, AN515 (in part) and AN526 (in part) dash numbers; not transcribed.

Related

CalculatorPart number cross-referenceType any MS51957 number and land on its row.GuideScrewsThe family side by side.Data sheetMS27039Screw, Machine, Pan Head, Structural, Cross RecessedData sheetMS35206Screw, Machine, Pan Head, Cross-Recessed, Carbon Steel, Cadmium Plated, UNC-2A

Sources

Educational reference only. not approved data. Always consult the applicable SRM, AMM, or AC 43.13-1B and your certifying authority.
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