Rivets

Taper Lock

- Considered the strongest fasten due to the constant and complete load applied by the fastener when installed - A special tapered drill must be used to drill must be used in conjunction with these fasteners. - to remove use two people one from the bottom and one from the top pulling and pushing - used near landing gear (very hard to work with)

lock bolts

- D in 32nds - L in 16ths - 3 type of lock bolts: pull type, blind type, and stump type - pull type pulls the metals together, forces a collar into the grooves and shears the pin at the relive point - blind type pulls the stem forming a shop blind side and shears the stem - stem type are for applications with little space and are installed in the same manner as Hi shears - the collars are color coded as to the material they are used on - green for heat treated lock bolts - plain (silver) for aluminum - cad plated (gold) for heat treated steel

Hi Lock

- are typically installed in a interference fit hole by driving or taping - then; a shear collar is placed on the fastener - the collar is then driven down with an allen and open end or special tools until the hex shears free - available in 1/64 and 32OS

Cherry Lock

- can be used as size for size replacement of solid rivets due to implementation of a locking collar. - the jaw (head) on the gun must be the exact size needed in respect to the rivet size that is being shot - 5 rivet - 5 jaw etc - Both standard and oversize (+1/64th) sizes are available, the correct drill must be used as per the MFG's chart when using oversized rivet. - it is paramount that the correct length of rivet be determine, if the length selected is to short the collar will set prematurely causing deformation of the fastener, to long and the fastener will be loose. - this can be avoided by use of a grip gage. - once installed locking collar must be inspected for proper seat

Hi Shear Rivet

- can carry the same loads as the same size AN Bolt - As the collar is driven onto the fastener it fills the void and the excess is trimmed

Cherry Max

- has an anvil washer - the max fastener itself is the same as the lock, the addition of the driving anvil is the one major difference between the two - the advantage of the max is you can pull any size with one gun

Mechanical lock rivets

- huck loc rivet - huck lock rivets can be used size for size when placing solid rivets - they are standard size - they can be obtained in 5056, 2024, Ti and Monel

Hi Tigue

- looks almost identical to a hi lock with the exception of a bead at the base of the grip - the bead creates a pre load on the surrounding material preventing movement within the join, thus preventing failure from work hardening

Rivnut

- non structural fastener - to install drill the proper sized hole, notch the hole with the notcher and squeeze the rivet in place - do not over squeeze you will strip the threads out instantly.

Cherry buck

- rivet is made up of two different Ti alloys - 6AL-4V for the upper portion and Ti-Cb for the lower - When driven the more ductile Ti-Cb forms the shop head - Typically used in turbine sections.

olympic lock

- same as the cherry lock and max in function and installation, the main difference is in the construction, the stem stopping step is inside of the sleeve and the locking wedge being part o the formed sleeve - often referred to as the no spin lock rivet.

Cherry friction lock

- self plugging type fastener, available in 470 or 426 - fastener relies on friction of the compressed outer shell force against the car to stay intact - if replacing a solid rivet one D larger rivet must be used in the event of fastener failure.

Jo Bolt

- used in high strength close tolerance applications where standard AN MS NAS bolts cannot be installed due to lack of access - the flat is driven with special tools until the vase is drawn up compressing the material at which point the flat breaks off

Blind and pop rivets

- used in non-structural applications only - universal or countersunk - can be made of aluminum, steel, or monel

A rivet should extend beyond the base metal by

1 and 1/2 times the rivet diameter beyond the base metal to produce a shop head to fill the hole.

Drilling steps of a rivet

1. file end of term flat. 2. center punch with none spring loaded punch 3. drill off tapered part of stern far enough to pull the lock out 4. pry or peal the remainder of locking collar 5. drill almost through the rivet head 6. pry off rivet head 7. drive rivet from hole (steel low rpm high pressure / aluminum high rpm low pressure)

The Hi Locks Rivets are available in what sizes

1/64 & 32 OS

What are the most common type of rivets used

470 and 426

455 rivet is

A brazier head

426 rivet is

A countersunk head

442 rivet is

A flat head

Hi Shear Rivet can carry the same loads as the same size

AN Bolt

What are the two primary series solid shank rivets in use

AN and MS20

AMS

Aeronautical Material specs

AS

Aeronautical Standard

AN

Air force Navy

AND

Air force Navy Design

Internal wrenching bolts - allen bolts

Allen ms20004 through 200024 are high tensile strength bolts Due to shoulder or audio you at the head of the bolt a counter sunk washer ms20002c must be used or a relief made in the metal so as not to cause stress riser (special washer champer washer Nuts all just muc have a locking device of some sort 2 type of nut self locking and non self locking No more than —- threads and no less than —- threads Anchor nuts (nut plates

ASTM

American Society for Testing Materials

ASA

American Standards Association

Bolts Selection

Bolts are measured in 1/16 for the D and 1/8 for the length up to 7/8 From 1 niche or -10 to -17 and two inch or -20 to -27 With the exception of the an3 bolt fastener smaller then 1/4 inch are measured in gages 0-12 everything else is a wire gauge The other length that must be accounted for is the gripe length 3 different types of washers Light-1/2, standard (9/16) and heavy+1/2 Booths smaller than an 3 cannot be sued in structural appcaitons an4 - an20 can if a bolt PN has an A following it there is no hold in Teh shank the A stands for a sense of a hole in the shank If a bolt PN has an H following the diameter it indicates a drill head for safetying. **Close tolerance bolts are ground to within +.000 and -.0005

The lock bolt D and L is measure in

D = 32nds, L = 16th

Turn locks

Dzus Fastener - quick release fasteners used in non structural high used area, oil doors, cowls, etc Good for repeated use application where normal fasteners might where excessively or cause damage and structural strength is not necessary. Threaded Fasteners there are four different thread types use I'd in standard aviation bolts: NC - national coarse, NF - national fine, UNC - unified national coarse, UNF - unified national fine Use fine thread in aviation -the difference between coarse and fine is the pitch and court of the thread (TPI - threads per inch) - # of complete threads in one inch of fastener The is also class of fit designation they run 1-5: 1 being the loosest, 5 being the tightest Typically aviation bolts are class 3 fine thread and screws ...

The collars one bolts are color coded as to the material they are used on. What are the three color?

Green - for heat treated lock bolts Plain (Silver) - for aluminum Cad plated (Gold) for heat treated steel

Mechanical lock rivets are

Hugh lock rivets and can be used size for size when replacing solid rivets. They are standard size and can be obtained in 5056, 2024, Ti and Monel

Blind Rivets and pop rivets are used

In non structural applications only and can be universal or countersunk. They can be made of aluminum, steel, or monel.

With Rivets, the standards are

Industry wide. Makes for economical production and reproduction.

How does a Pull Type lock bolt work?

It pulls the metals together, forces a collar into the grooves and shears the pin at the relief point

How does a Blind Type lock bolt work?

It pulls the stem forming a shop blind side and shears the stem.

MS

Military Standard

NAS

National Aerospace Standard

NAF

Naval Aircraft Factory

What are the three type of lock bolts?

Pull Type, Blind Type, and Stump Type

After the MFG digits on a rivet what is the next call out of letters

Rivet alloy A - Plain 1100 AD - Dimple 2117 T3 B - Raised Cross 5056 H32 D raised dot 2117 T31 D raised dot 2117 T3 DD two raised dashes 2024 T31 E Raised ring 7075 T73 F rivet plain CRES Steel M two dimples monel steel

Throw away a ______ after use.

Self locking nut

Cherry friction lock rivets are

Self plugging fasteners available in 470 or 426. They relay on friction of the compressed outer shell force against the core to stay intact. If replacing one D larger rivet must be sued in the event of a fastener failure.

SAE

Society of Automotive Engineers

The Olympic Lock Rivet is the same as_______ an is often referred to as the __________

The Cherry Lock. No Spin Lock Rivet

What do the last two numbers on a 470 or 426 rivet identify as

The manufacturer's (MFG's) head type

After the MFG and Letter Call out on a rivet what is next

The rivet diameter in 1/32nds

How does a Stump type lock bolt work?

They are for applications with little space and are installed in the same manner as Hi Shears

Lot Control numbers are used for

Traceability of the item back to its manufacturer.

Cherry Buck Rivets are typically used in

Turbine sections

Cherry Buck Rivets are made up of ______ for the upper and lower.

Two different Ti Alloys: Upper - 6AL-4v Lower: Ti-Cb (Titanium-Columbium) Alloy

How are Hi Locks installed

Typically in a interference fit hole by driving or taping, then a shear collar is placed on the fastener. The collar is then driven down with an Allen and open end or special tools until the hex shears free

470 rivet is a

Universal head

lab project notes

VB (vacuum bag) cut, Pour, squeegee(not hard), Put foam on fabrics on first application only In class Put water on top of the resin to kill the oxygen and prevent fire Key is prep Get a respirator and eyewear - miocroballons can kill even when sanding or cleaning Gel is unusable in minutes