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LA4–440–1MD

ALA Floating Self-Clinching Fasteners · Unified · PDF page 13 · PEM Fastener Catalogue

ALA Floating Self-Clinching Fasteners · Unified · thread .112-40 (#4-40)

Self-locking, 400 series stainless, Passivated retainer · black dry-film lubricant nut.

Also written as LA4-440-1MD.

Part number breakdown

SegmentCodeMeaning
TypeLASelf-locking
Retainer Material Code4400 series stainless
Thread440Thread size .112-40 (#4-40)
Shank1—
Finish CodeMDPassivated retainer · black dry-film lubricant nut

Dimensions

Defines A, C, D, T2. Technical cross-section diagram of a clinching fastener with the following dimensional labels: A: Thickness of the clinching base/flange. C: Outer diameter of the base. D: Outer diameter of the body/housing. T₂: Length/depth of the threaded internal component. Key Features: Internal threads, multi-piece assembly, and cross-hatched sections indicating a metal component.Defines E. Subject: Technical engineering diagram of a circular component, likely a tube or pipe end. Key Features: Dimension E: Represents the total outer diameter of the assembly. Concentric/Eccentric Rings: Shows multiple circular layers, with an arrow pointing to an internal feature or "Formed" area. Centerlines: Horizontal and vertical dashed lines indicate symmetry and axial center. Line Styles: Uses solid lines for visible edges and dashed lines for hidden features or internal diameters.Defines float. Technical diagram showing a top-down view of a mechanical component: Central feature: A circular opening housed within a square element. Housing: Outer concentric circles with a serrated or threaded ring detail. Float specification: An orange arrow points to the internal square, corresponding to text indicating a float of .015”/0.38 mm minimum in all directions from the center (.030”/0.76 mm total. Alignment: Horizontal and vertical centerlines intersect at the midpoint of the component.
DimensionValue
Thread Size.112-40 (#4-40)
Type – Self-Locking (Fastener Material) › 400 Series StainlessLA4
Thread Code440
Shank Code1
A (Shank) Max..038
Min. Sheet Thickness.038
Hole Size in Sheet +.003 −.000.290
C Max..289
D Max..290
E ±.015.360
T1 Max..130
T2 Max..190
Min. Dist. Hole ℄ To Edge.30

Material and finish

PropertyValue
TypeLA4
Fastener MaterialsThreads › Self-locking › Internal, UNJ Class 3B per ASME B1.15 / MJ Class 4H6H per ASME B1.21M (M6 thread 4H5H); Retainer › Hardened 400 Series Stainless Steel; Nut › 300 Series Stainless Steel
Standard FinishesSelf-locking › Retainer › Passivated and/or tested per ASTM A380; Self-locking › Nut › Black Dry-film Lubricant
For Use In Sheet HardnessHRB 88 / HB 183 or Less

Source: Material and Finish Specifications · PDF page 13

Performance data

PropertyValue
Thread Code440
Test Sheet Material › 300 Series Stainless Steel › Installation (lbs.)9000
Test Sheet Material › 300 Series Stainless Steel › Retainer Pushout (lbs.)200
Test Sheet Material › 300 Series Stainless Steel › Retainer Torque-out (in. lbs.)85

Source: A4/LA4 Nuts (3) · PDF page 14

Installation tooling

PropertyValue
Thread Code440/M3
Counterbore A › ±.001 (in.).054
Counterbore A › ±0.03 (mm)1.37
Hole Depth Below Counterbore B › ±.005 (in.).258
Hole Depth Below Counterbore B › ±0.13 (mm)6.55
Anvil Part Number8013889
Punch Part Number975200048

Source: PEMSERTER® Installation Tooling – AC/AS/LAC/LAS/A4/LA4 Nuts · PDF page 14

Axial strength and tightening torque

PropertyValue
Thread Code440
Locknut Min. Axial Strength (lbs.)1085
Mating Screw Strength Level (ksi)180
Mating Screw Tightening Torque (in. lbs.)15.8

Source: Axial Strength and Tightening Torque – Types LAC/LAS/LA4 · PDF page 12

Single groove identifies A4/LA4 for stainless sheets. PEM® Double Squares: Registered trademark feature located on the top inner rim of the fastener. PEM® Single groove: Registered trademark feature on the outer side wall; identifies products for installation into stainless steel sheets (A4 and LA4 types. Fastener Type: Circular threaded insert with a knurled base and specialized identifying marks.The image displays four types of circular aerospace fasteners: AC/AS: Standard non-locking fastener. LAC/LAS: Locking fastener with a dark-colored insert. LA4: Locking thread version with a dark insert. A4: Non-locking thread version.

Source

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Part number breakdownDimensionsMaterial and finishPerformance dataInstallation toolingAxial strength and tightening torqueRelated drawingsSource