An Aerospace Manufacturing Perspective Aerospace Fastener Applications Part 2 1.

An Aerospace An Aerospace Manufacturing Manufacturing

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Aerospace Fastener ApplicationsAerospace Fastener Applications

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Aerospace Rivets

Primarily used to fasten aerospace skins to the sub-structure

Concerned mainly with shear and tension loads. Two types of rivets:

– Solid Rivet– Blind Rivet

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Aerospace Rivets

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• Rivets on the skin of a Boeing 737

Aerospace Solid Rivets

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• Universal solid rivets on the skin of a Boeing 737

•Note that they are not flush with the skin


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• Countersunk solid rivets on the engine pylon of a Boeing 737

• Note that these rivets are flush with the surface


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Aerospace Solid Rivets - Identification

Rivets manufactured in accordance with the AN/MS standards are identified by a four part code:

1. AN or MS specification and head type

2. one or two letters that indicate the material

3. shank diameter in 1/32nd inch increments

4. a dash followed by a number that indicates rivet length in 1/16th inch increments.

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• Aircraft rivets are made of many materials, and come in a wide variety of shapes and sizes

• How do you select the right size?

• How do you select the right material?

•We must know what the part number tells us…


Example: rivet identification standard universal head solid rivet Material: 2117-T4 aluminium 1/8 inch diameter 5/16 inch in length Rivet ID = either AN470AD4-5 or MS20470AD4-5

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Same rivet, different material:1100 aluminium – AN470A4-5 or MS20470A4-5.

AN470 or MS20470 denote the specification for universal head types AD is the material code for 2117-T4

– (A=1100, B=5056, C=copper, D=2017, DD=2024, F=stainless and M=Monel)

4 = 4/32 or 1/8 inch diameter -5 = 5/16 inch length

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Aerospace Solid Rivet Installation

Rivet installation summary– Drill appropriately sized holes– Deburr holes– Secure pieces together with Clecos– Install rivet, buck with rivet gun or use a rivet

squeezer

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• .032” 2024-T6 sheet aluminum to be joined with rivets•Rivet gun•Bucking bar•Drill•Drill bit and chuck key•Center punch•Cleco•Cleco pliers


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• Drilling holes with a #30 drill bit

• Use 1/8” rivets with a #30 (.1285”) drill bit


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• Deburr the holes by rotating (by hand) a much larger drill bit in the holes

• This removes any metal shavings caused by drilling


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• Position the pieces together and secure using Clecos

•Clecos maintain proper alignment of the pieces while rivets are being installed


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• Place the rivet in the hole

• Make sure you are using the correct size, material, and type of rivet


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• Align the rivet gun on the rivet head

• Hold the bucking bar on the opposite end of the rivet

• Pull the trigger on the rivet gun to hammer the rivet in place


Solid rivets can be installed using a rivet squeezer instead of a pneumatic rivet gun

The squeezer is hand operated

The squeezer uses various inserts depending on the type and size of rivet being installed

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Aerospace Blind Rivets

Used when you cannot physically access one side of the work

Blind rivets are hollow, and thus weaker than solid rivets To retain strength of the joint:

– stronger material, larger diameter rivets, or more are necessary and of course

20–50% heavier than a solid rivet because of steel stem

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Aerospace Blind Rivets

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Aerospace Rivets – Fuselage Repair

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•Note that solid fasteners are used except in the middle of the patch

• Why would you use blind fasteners in this application?

• Exterior of a riveted patch fuselage skin patch

Aerospace Rivets – Fuselage Repair

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•Because the stringer on the interior of the fuselage prevents the bucking a solid rivet requires

• Blind rivets are the only option when access is restricted

• Interior of a riveted fuselage skin patch

Quality Assurance of Aerospace Fasteners

Aerospace Fasteners Material Selection

Aerospace Fasteners Testing

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Background Some factors to be considered before material selection

are: The max. and min. operating temperaturesThe corrosiveness of the environmentFatigue and impact loading

Always try to use standard fasteners, such as AN, MS, MIL, NAS, SAE

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Alloy Steels Aluminum Titanium Stainless Steel Superalloys

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Aluminum is the predominant material used in the manufacture of commercial aircraft.

Table 3 lists the typical aluminum alloys used in commercial aircraft.

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Basic Aerospace Fasteners Application

The basic applications (or needs) for aerospace fasteners are:– Shear – Tension– Fatigue– Fuel tightness– High temperature– Corrosion control

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Aerospace Fasteners Testing

Analyzing a Joint– Calculate all the load required for each type of

joint failure: Rivet Shear Sheet Tensile Bearing Sheet Shear

– Failure will occur in the mode that corresponds with the lowest load carrying capability.

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Aerospace Fastener Standardization

Most aerospace hardware is manufactured per government standards

The three most common aircraft fastener standards used are:– AN = Air Force/Navy– NAS = National Aerospace Standards– MS = Military Standards

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Common Standardized Fasteners

– Bolts– Nuts– Washers– Turnbuckles– Cotter pins– Screws– Rivets– Plumbing fittings (pipes and tubes)

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An Aerospace Manufacturing Perspective Aerospace Fastener Applications Part 2 1.

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