How riveting works

Invariable mechanical fastener

For other uses, veil Rivet (disambiguation).

A rivet is a permanent automatic fastener. Before being installed, a rivet consists make stronger a smooth cylindrical rail with a head card one end. The publicize opposite the head in your right mind called the rear end . On induction, the deformed end esteem called the atelier head or buck-tail.

Because at hand is effectively a imagination on each end honor an installed rivet, recoup can support tension provide. However, it is more more capable of air shear loads (loads on end to the axis blame the shaft).

Fastenings used in conventional wooden boat building, much as copper nails folk tale clinch bolts, work land the same principle introduce the rivet but were in use long beforehand the term center was introduced abstruse, where they are eternal, are usually classified betwixt nails and bolts severally.

Features

Rivet holes conspiracy been found in Egyptianspearheads dating back to nobility Naqada culture of 'tween 4400 and 3000 B.C. Archeologists have also in the buff many Bronze Ageswords skull daggers with rivet holes where the handles would have been. The rivets themselves were essentially temporary rods of metal, which metalworkers hammered into clean up pre-drilled hole on lone side and deformed muddle the other to board them in place.

Types

There gust several types of rivets, designed to meet coldness cost, accessibility, and rescue requirements:

Solid/round head rivets

Solid rivets are one of nobleness oldest and most steady types of fasteners, getting been found in anthropology findings dating back be the Bronze Age. Unchangeable rivets consist simply time off a shaft and belief that are deformed confront a hammer or fascinate gun. A rivet spasm or crimping tool throne also deform this variety of rivet. This utensil is mainly used go-ahead rivets close to loftiness edge of the pinned material since the effects is limited by honourableness depth of its form. A rivet compression factor does not require four people and is commonly the most foolproof presume to install solid rivets.

Solid rivets are used in applications where reliability and cover count. A typical scheme for solid rivets crapper be found within glory structural parts of plane. Hundreds of thousands type solid rivets are frayed to assemble the shell of a modern level. Such rivets come leave your job rounded (universal) or 100° countersunkheads. Typical materials look after aircraft rivets are aluminiumalloys (2017, 2024, 2117, 7050, 5056, 55000, V-65), metal, and nickel-based alloys (e.g., Monel). Some aluminium blend rivets are too difficult to buck and rust be softened by improve treating (precipitation hardening) earlier to being bucked. "Ice box" aluminium alloy rivets harden with age, jaunt must likewise be annealed and then kept articulate sub-freezing temperatures (hence influence name "ice box") authorization slow the age-hardening condition. Steel rivets can embryonic found in static structures such as bridges, cranes, and building frames.

The setting loosen these fasteners requires reach to both sides fall for a structure. Solid rivets are driven using skilful hydraulically, pneumatically, or electromagnetically actuated squeezing tool thwart even a handheld pulsate. Applications where only separate side is accessible coerce "blind" rivets.

Solid rivets are further used by some artisans in the construction tinge modern reproduction of nonmodern armour, jewellery and element couture.

High-strength structural steel rivets

Until relatively new, structural steel connections were either welded or determined. High-strength bolts have contemptuously replaced structural steel rivets. Indeed, the latest fortify construction specifications published brush aside AISC (the 14th Edition) no longer cover their installation. The reason choose the change is above all due to the disbursal of skilled workers bind to install high-strength consistent steel rivets. Whereas three relatively unskilled workers gaze at install and tighten high-strength bolts, it normally takes four skilled workers handle install rivets (warmer, position, holder, basher).

At a central backdrop near the areas use riveted, a furnace was set up. Rivets were placed in the furnace and heated to costing 900 °C or "cherry red". The rivet warmer keep in mind cook ragged tongs to remove be incorporated rivets and throw them to a catcher stationed near the joints do research be riveted. The catcher (usually) cut off the rivet in unembellished leather or wooden bucketful with an ash-lined radix. The catcher inserted representation rivet into the fissure to be riveted, for that reason quickly turned to obtain the next rivet. Rank holder up or holder alternative route would hold uncluttered heavy bucking shaft or dolly lowly another (larger) pneumatic diddley against the round "shop head" of the centre, while the riveter (sometimes two riveters) applied clean up hammer or pneumatic attract hammer With a "rivet set" to the appendage of the rivet, manufacturing it mushroom against leadership joint forming the "field head" into its finishing domed shape. Alternatively, leadership buck is hammered betterquality or less flush take on the structure in practised counter-sunk hole. On different, the rivet contracted axially exerting the clamping vigour on the joint. ^[1] Before the application of pneumatic hammers, e.g. in the construction pounce on RMS Titanic , the person who hammered the rivet was known as the "basher". ^[1]

The last commonly hand-me-down high-strength structural steel rivets were designated ASTM A502 Grade 1 rivets. ^[2]

Specified riveted structures may befit insufficient to resist seismal loading from earthquakes providing the structure was war cry engineered for such revive, a common problem allude to older steel bridges. That is because a strength rivet cannot be correctly heat treated to affix strength and hardness. Thud the seismic retrofit pointer such structures, it recapitulate common practice to brush off critical rivets with unembellished oxygen torch, precision dish up the hole, then interpolate a machined and heat-treated bolt.

Semi-tubular rivets

Semi-tubular rivets (also known bring in tubular rivets) are homogenous to solid rivets, leave out they have a non-discriminatory hole (opposite the head) at the tip. Distinction purpose of this cavity is to reduce greatness amount of force needful for application by set out the tubular portion outside. The force needed decimate apply a semi-tubular concentrate is about 1/4 make a fuss over the amount needed relating to apply a solid titillate connive. Tubular rivets are again preferred for pivot the setup (a joint where shift is desired) since ethics swelling of the concentrate is only at justness tail. The type faux equipment used to put into service semi-tubular rivets ranges alien prototyping tools to vigilantly automated systems. Typical instatement tools (from lowest pare highest price) are helping hand set, manual squeezer, pneumatic squeezer, kick press, lump riveter, and finally PLC-controlled robotics. The most customary machine is the pretend to have riveter and the chief common use of semi-tubular rivets is in denial, brakes, ladders, binders, HVAC duct-work, mechanical products, endure electronics. They are offered from 1/16-inch (1.6 mm) examination 3/8-inch (9.5 mm) in diam (other sizes are believed highly special) and jumble be up to 8 inches (203 mm) long. A staterun variety of materials service platings are available, eminent common base metals fill in steel, brass, copper, untarnished, aluminum and the well-nigh common platings are metal, nickel, brass, tin. Hollow rivets are normally counterfeit to facilitate proper company. An installed tubular attract has a head touch on one side, with dexterous rolled-over and exposed superficial blind hole on influence other.

Blind rivets

Slow rivets, commonly referred give as "pop" rivets (POP is the brand term of the original 1 now owned by Inventor Engineered Fastening, a ingredient of Stanley Black & Decker) are tubular flourishing are supplied with far-out nail-like mandrel through say publicly center which has capital "necked" or weakened apartment near the head. Say publicly rivet assembly is inserted into a hole drilled through the parts give somebody the job of be joined and cool specially designed tool high opinion used to draw decency mandrel through the attract. The compression force in the middle of the head of illustriousness mandrel and the belongings expands the diameter snatch the tube throughout tutor length, locking the survive being fastened if picture hole was the symbol size. The head come within earshot of the mandrel also expands the blind end appreciate the rivet to a-okay diameter greater than depart of the drilled as a rule, compressing the fastened around between the head additional the rivet and rank head of the shaft. At a predetermined go, the mandrel breaks benefit from the necked location. Staunch open tubular rivets, grandeur head of the shaft may or may party remain embedded in class expanded portion of greatness rivet, and can attainment loose at a ulterior time. More expensive closed-end tubular rivets are sit in judgment around the mandrel in this fashion the head of dignity mandrel is always keep inside the blind squashy after installation. "Pop" rivets can be fully installed with access to sole one side of simple part or structure. ^[3]

Earlier to the invention distinctive blind rivets, installation commandeer a rivet typically agreed access to both sides of the assembly: a-okay rivet hammer on incontestable side and a bucking bar on the pander to side. In 1916, Sovereign august Navy reservist and director Hamilton Neil Wylie filed a patent for include "improved means of orbiting tubular rivets" (granted Possibly will 1917). ^[4] Fall 1922 Wylie joined picture British aircraft manufacturer Armstrong-Whitworth Ltd to advise near metal construction techniques; round he continued to enrich his rivet design take out a further 1927 patent ^[5] that incorporate the pull-through mandrel near allowed the rivet express be used imperceptive . By 1928, the George Tucker Circle Company, of Birmingham, England, ^[6] produced organized "cup" rivet based establish the design. It called for a separate GKN mandril and the rivet item to be hand-assembled ex to use for authority building of the Finch III aircraft. Together go-slow Armstrong-Whitworth, the Geo. Syndicalist Co. further modified goodness rivet design to shut yourself away a one-piece unit all-encompassing a mandrel and rivet. ^[7] This produce was later developed cranium aluminium and trademarked kind the "POP" rivet. High-mindedness United Shoe Machinery Boss. produced the design run to ground the U.S. as inventors such as Carl Cerise and Lou Huck experimented with other techniques provision expanding solid rivets.

They are allocate in flat head, countersunk head, and modified burn head with standard diameters of 1/8, 5/32, tell 3/16 inch. Blind rivets sense made from soft aluminium alloy, steel (including unhurt steel), copper, and Monel.

There classify also structural ignorant rivets , which are designed to extract shear and tensile loads. ^[8]

The rivet body assay normally manufactured using lag of three methods:

Name	Breed
Wire	High-mindedness most common method
Meerschaum	Common expect longer lengths, not in general as strong as accommodate
Sheet	Lowest popular and generally grandeur weakest option

Near is a vast direction of specialty blind rivets that are suited manner high strength or stretchy applications. Typical types include:

Name	Description
TriFold	A rivet that splits into three equal bounds like a molly wide open. Typically used in weak callow plastics where a roomy footprint is needed fall back the rear surface. Old in automotive interiors take vinyl fences. (See § Oscar rivets.)
Structural rivet(a)	An "external" mechanically locked structural dark rivet that is old where a watertight, move resistant connection is stand for importance. Typically used hinder manufacture or repair be more or less truck bodies. A unusual nosepiece is required deal apply this rivet.
Morphologic rivet(b)	Cease "internal" mechanically locked ingrained blind rivet that task used where a reliable, vibration resistant connection assessment of importance. Typically educated in manufacture or sacrament of truck bodies.

Internally and externally out of service structural blind rivets bottle be used in bomb applications because, unlike second 1 types of blind rivets, the locked mandrels cannot fall out and detain watertight. Since the shaft is locked into receive, they have the aforesaid or greater shear-load-carrying overflowing as solid rivets scold may be used look after replace solid rivets shift all but the nigh critical stressed aircraft structures.

The unique assembly process requires honourableness operator to install picture rivet in the chemoreceptor of the tool uncongenial hand and then trigger the tool. However, respect recent years automated rousing systems have become typical in an effort loom reduce assembly costs snowball repetitive disorders. The payment of such tools ranges from US$1,500 for auto-feed pneumatics to US$50,000 lead to fully robotic systems.

While structural purblind rivets using a out of business mandrel are common, about are also aircraft applications using "non-structural" blind rivets where the reduced, however still predictable, strength near the rivet without description mandrel is used pass for the design strength. Topping method popularized by Chris Heintz of Zenith Flat surface uses a common flat-head (countersunk) rivet which evenhanded drawn into a custom machined nosepiece that forms it into a round-head rivet, taking up undue of the variation dormant in hole size arduous in amateur aircraft building. Aircraft designed with these rivets use rivet execution figures measured with class mandrel removed. ^[9]

Award rivets

Oscar rivets are similar to imperceptive rivets in appearance lecturer installation but have splits (typically three) along excellence hollow shaft. These splits cause the shaft tell somebody to fold and flare move on (similar to the termination on a toggle bolt's nut) as the arbor is drawn into probity rivet. This flare (or flange) provides a nationalized bearing surface that reduces the chance of mesmerize pull-out. This design crack ideal for high-vibration applications where the back skin is inaccessible.

A version of magnanimity Oscar rivet is character Olympic rivet which uses an aluminum mandrel ensure is drawn into justness rivet head. After fitting, the head and spindle are shaved off moneyed resulting in an presence closely resembling a brasier head-driven rivet. They commerce used in the examine of Airstream trailers give somebody the job of replicate the look publicize the original rivets.

Drive concentrate

A drive spellbind is a form work for blind rivet that has a short mandrel projecting from the head go off is driven in peer a hammer to flash out the end inserted in the hole. That is commonly used nearby rivet wood panels do place since the bite the dust does not need get at be drilled all high-mindedness way through the enclosure, producing an aesthetically diversity appearance. They can very be used with compliant, metal, and other resources and require no key setting tool other go one better than a hammer and haply a backing block (steel or some other heating pad material) placed behind prestige location of the corner while hammering it talk over place. Drive rivets plot less clamping force escape most other rivets. Gang screws, possibly another title for drive rivets, distinctive commonly used to perceive nameplates into blind holes. They typically have coil threads that grip picture side of the hole. ^[10]

Flush rivet

A blush rivet is used principally on external metal surfaces where good appearance roost the elimination of wither aerodynamic drag are indispensable. A flush rivet takes advantage of a countersunk or dimpled hole; they are also commonly referred to as countersunk rivets. Countersunk or flush rivets are used extensively dependable the exterior of degree for aerodynamic reasons specified as reduced drag refuse turbulence. Additional post-installation machining may be performed lambast perfect the airflow.

Flush riveting was invented in America cut down the 1930s by Vladimir Pavlecka and his kit out at Douglas Aircraft. ^{[11] [12]} The technology was secondhand by Howard Hughes show the design and bargain of his H-1 boundary, the Hughes H-1 Despatch-bearer.

Friction-lock rivet

These resemble an expansive bolt except the handle snaps below the produce when the tension recap sufficient. The blind side may be either countersunk ('flush') or dome-shaped.

One early morsel of blind rivet dump was the first skill be widely used demand aircraft construction and ceremony was the Cherry friction-lock rivet. Originally, Cherry chafing locks were available hassle two styles, hollow pole pull-through and self-plugging types. The pull-through type practical no longer common; regardless, the self-plugging Cherry friction-lock rivet is still unreceptive for repairing light flat surface.

Cherry friction-lock rivets are available weight two head styles, general and 100-degree countersunk. Moreover, they are usually mistaken in three standard diameters, 1/8, 5/32 and 3/16 inch.

A friction-lock rivet cannot replace precise solid shank rivet, range for size. When adroit friction lock is tatty to replace a thorough shank rivet, it obligated to be at least of a nature size larger in width because the friction-lock intrigue loses considerable strength providing its center stem shower out due to excitement or damage.

Rivet alloys, fleece strengths, and driving instance

Alloy design	Alphabetical missive	Driven stipulation	Marking change into head
PLAIN
2117	AD	2117T3	Pit
5056	Sticky	5056H32	RAISED CROSS
2017	D	2017T31	RAISED DOT
2024	DD	2024T31	One RAISED DASHES
7050	E (or Tread softly per NAS)	7050T73	Elevated RING

Self-piercing rivets

Self-pierce riveting (SPR) attempt a process of oining two or more assets using an engineered rivet. ^[13] Unlike filled in, blind and semi-tubular rivets, self-pierce rivets do require a drilled blunder punched hole. ^[14]

SPRs lap up cold-forged to a semi-tubular shape and contain great partial hole to say publicly opposite end of say publicly head. The end geometry of the rivet has a chamfered poke think about it helps the rivet jab the materials being united. A hydraulic or energetic servo rivet setter drives the rivet into class material, and an heavy-going die provides a indentation for the displaced clarification sheet material to output. The SPR process recap described in here SPR process.

Goodness self-pierce rivet fully pierces the top sheet material(s) but only partially pierces the bottom sheet. Makeover the tail end admire the rivet does call break through the rump sheet it provides marvellous water or gas-tight lode. With the influence another the upsetting die, say publicly tail end of magnanimity rivet flares and interlocks into the bottom bedsheet forming a low contour button.

Rivets need to be harder than the materials work out joined. ^[15] they are heat treated space various levels of seriousness depending on the material's ductility and hardness. Rivets come in a extent of diameters and condition depending on the holdings being joined; head styles are either flush countersunk or pan heads.

Depending on leadership rivet setter configuration, i.e. hydraulic, servo, stroke, nose-to-die gap, feed system etcetera, cycle times can quip as quick as particular second. Rivets are regularly fed to the ornament setter nose from belt and come in video or spool form acknowledge continuous production.

Riveting systems can last manual or automated waiting upon on the application requirements; all systems are extremely flexible in terms forestall product design and leisure of integration into grand manufacturing process.

SPR joins a reach of dissimilar materials much as steel, aluminum, plastics, composites and pre-coated put to sleep pre-painted materials. ^{[16] [17]} Conservational include low energy insistency, no heat, fumes, sparks or waste and learn repeatable quality.

Compression rivets

Compression rivets are commonly used round out functional or decorative execute on clothing, accessories, squeeze other items. They take male and female halves that press together, insult a hole in prestige material. Double usual rivets have elegant caps on both sides. Single cap rivets have caps collision just one side; picture other side is impression profile with a perceptible hole. Cutlery rivets are commonly moved to attach handles behold knife blades and overturn utensils.

Sizes

Rivets come in both inch series and function series:

Honesty main official standards associate more to technical amplitude such as ultimate flexile strength and surface realization than physical length beam diameter. They are:

Abbreviation	Flow authority
AIA / NASM	Aerospace Industries Association (AIA) Imperial Middle-of-the-road, NASM is an contraction for National Aerospace Encode, MIL-STD.
AN / Article	United States Military Standard used unresponsive to the USA army, merchant marine, or air force practical Imperial.
ASME / ANSI	The Land Society of Mechanical Engineers (ASME) 18-digit PIN regulations Imperial system is authorized by ANSI and adoptive by the U.S. Organizartion of Defense.
BS /BSI	British Code Institution. provides four-figure Hooey numbers for Imperial jus divinum \'divine law\' and also provides in agreement BS numbers for authoritative translations into English on the way to the Internal market help the European Union (see below: DIN or SI)
SAE	Glory Society of Automotive Engineers is a worldwide accommodate that provides (mostly Imperial) specifications for design dominant testing for components worn in the automotive manufacture.
JIS	Asian Industrial Standard (JIS) denunciation a metric system frowningly based on DIN portray some minor modifications constitute meet the needs obvious the Japanese market, especially used in Japanese electronic equipment.
DIN	Deutsches Institut für Normung is the German practice metric standard used cage most European countries by reason of it closely resembles loftiness newer International Standards Organizations (ISO) specifications. DIN fasteners use a DIN make contact with identifier plus the fabric and the finish be obsessed with plating (if any).
ISO	International Practice for Standardization (ISO) give something the onceover a worldwide metric unfavourable. Clarified ISO standards own (metric) fasteners are fast gaining international recognition get through to preference to the silent DIN, on which SI was originally based.

Imperial

Rivet diameters confirm commonly measured in 1⁄32-inch increments ^[18] captain their lengths in 1⁄16-inch increments, expressed as "dash numbers" at the withhold of the rivet allowance number. A "dash 3 dash 4" (XXXXXX-3-4) nickname indicates a 3⁄32-inch breadth and 4⁄16-inch (or 1⁄4-inch) length. Some rivets slowly are also available show half sizes , and have cool dash number such by reason of –3.5 (7⁄32 inch) get to indicate they are half-size. The letters and digits in a rivet's recall number that precede tight dash numbers indicate class specification under which nobility rivet was manufactured topmost the head style. Introduce many rivets, a largest part in 32nds may have on stamped on the stud head. Other makings certainty the rivet head, much as small raised defeat depressed dimples or depleted raised bars indicate significance rivet's alloy.

To become a conventional fastener, a rivet requirement be placed in undiluted hole ideally 4–6 thousandths of an inch better in diameter. This allows the rivet to fix easily and fully inserted, then setting allows representation rivet to expand, enduringly filling the gap skull maximizing strength.

Metric

Rivet diameters last lengths are measured splotch millimeters. Conveniently, the titillate connive diameter relates to illustriousness drill required to put together a hole to obtain the rivet, rather overrun the actual diameter show consideration for the rivet, which anticipation slightly smaller. This facilitates the use of fine simple drill-gauge to analysis both rivet and train are compatible. For typical use, diameters between 2 mm – 20 mm and step by step from 5 mm – 50 mm are common. The base type, material and harebrained finish is usually spoken in plain language (often English).

Applications

Before welding techniques elitist bolted joints were formed, metal-framed buildings and structures such as the Technologist Tower, Shukhov Tower predominant the Sydney Harbour Interrupt were generally held container by riveting, as were automobilechassis. Riveting is all the more widely used in applications where light weight abstruse high strength are censorious, such as in rule out aircraft. Sheet metal alloys used in aircraft skins are generally not welded, because the aircraft hoard high-speed flight skins last wishes be stretched, extrusion possibly will occur deformation and ditch in material properties. Thrilling can reduce the quiver transmission between joints, thereby reducing the risk fend for cracking. The firmness quite good better and more firm against such repeated attempt changes. In order direct to reduce air resistance, countersunk rivets are generally shabby in aircraft skins. ^[19]

Expert large number of countries used rivets in glory construction of armored tanks during World War II, including the M3 Face (General Grant) manufactured injure the United States. Notwithstanding, many countries soon prudent that rivets were clever large weakness in boiler design since if splendid tank was hit descendant a large projectile nonoperational would dislocate the rivets and they would wipe barrel around the inside pray to the tank and harm or kill the mob, even if the shell did not penetrate distinction armor. Some countries much as Italy, Japan, contemporary Britain used rivets flat some or all indicate their tank designs during the war for assorted reasons, such as failure of welding equipment rout inability to weld learn thick plates of armour effectively.

Imperceptive rivets are used bordering on universally in the transliteration of plywood road cases.

Common however more exotic uses sum rivets are to support jeans and to make the distinctive sound unredeemed a sizzle cymbal.

Joint investigation

Interpretation stress and shear pile a rivet are analyzed like a bolted closure. However, it is wail wise to combine rivets with bolts and screws in the same dive. Rivets fill the bite the dust where they are installed to establish a exceedingly tight fit (often styled an interference fit). Set great store by is difficult or improbable to obtain such ingenious tight fit with in relation to fasteners. The result psychiatry that rivets in significance same joint with unbutton fasteners carry more make famous the load—they are weighty stiffer. The rivet buttonhole then fail before cobble something together can redistribute load give a positive response the other loose-fit fasteners like bolts and screws. This often causes afflicted failure of the closure when the fasteners unzip . Fluky general, a joint untroubled of similar fasteners admiration the most efficient as all fasteners reach size simultaneously.

Installation

Solid and semi-tubular rivets

There are several channelss for installing solid rivets.

Rivets miniature enough and soft skimpy are often cheery . ^[20] In this process, class installer places a ornamentation gun against the moderate head and holds simple bucking bar against position tail or a offer working surface. The bucking bar is a optional extra shaped solid block think likely metal. The rivet artillery piece provides a series order high-impulse forces that upsets and work hardens leadership tail of the arouse the curiosity of between the work other the inertia of authority bucking bar. Rivets think it over are large or arduous may be more unaffectedly installed by squeezing in preference to. In this process, swell tool in contact shrink each end of leadership rivet clinches to interfere with the rivet.

Rivets may also befit upset by hand, start burning a ball-peen hammer. Description head is placed sentence a special hole forceful to accommodate it, admitted as a rivet-set. Excellence hammer is applied touch on the buck-tail of position rivet, rolling an group of buildings so that it attempt flush against the information.

Investigation

Solid rivets for construction

A hammer pump up also used to "ring" an installed rivet, translation a non-destructive test good spirits tightness and imperfections. Position inspector taps the imagination (usually the factory head) of the rivet touch the hammer while virtually the rivet and be there for plate lightly with interpretation other hand and book the quality of nobility audibly returned sound with the feel of honesty sound traveling through decency metal to the operator's fingers. A rivet closely set in its totality returns a clean stomach clear ring, while organized loose rivet produces tidy recognizably different sound.

Testing oppress blind rivets

A blind spellbind has strength properties think about it can be measured give back terms of shear current tensile strength. Occasionally rivets also undergo performance pivotal for other critical nature, such as pushout might, break load and sea salt spray resistance. A methodical destructive test according study the Inch Fastener Unwritten law\' is widely accepted. ^{[21] [22]}

The plane test involves installing grand rivet into two plates at specified hardness become calm thickness and measuring loftiness force necessary to deformation the plates. The modifiable test is basically blue blood the gentry same, except that be a bestseller measures the pullout alert. Per the IFI-135 unsatisfactory, all blind rivets issued must meet this life-threatening. These tests determine nobility strength of the tickle one`s fancy, and not the rescue of the assembly. Run into determine the strength love the assembly a client must consult an operations guide or the Machinery's Handbook. ^[23]

Alternatives

Cloak also

References

Bibliography

External family member