PEM Self Clinching Fasteners

8/22/2019 PEM Self Clinching Fasteners

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THE

SELF-CLINCHING

FASTENER

HANDBOOK


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r e astener story . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2ow and why self-clinching works . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3natomy o se -c nc ng . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4ypes of self-clinching fasteners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5mportance o qua ty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6eliability in service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

nsta at on proce ure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8nstallation problems and solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Other considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Questions and Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Glossary of terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12dentification Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

contents

Copyright 2002


4/16

the deathatrevolutionized

productionfastening

hen K.A. Swanstromounded Penn Engineering &

anufacturing Corp. in 1942, he

so w t a revo ut onary new

pro uct: an easy-to- nsta , se -

clinching fastener that provides load-carrying threads in

metal sheets too thin to be tapped.

At first, Mr. Swanstrom produced his innovative design

with four machines in a Doylestown, Pennsylvania

garage. s s mp e operat on soon gave way to

a modern facility in Danboro, Pennsylvania as

manu acturers an eng neers a e recogn ze t e

benefits of self-clinching fasteners. They not only reduced

time, labor, weight and inventory on many assembly jobs,

but they also opened

engineers and design

assortment of thin-met

possible for the first ti

Industry-wide acceptance led to earnest production ofself-clinching fasteners shortly after World War II. As

n ustry s nee to o toget er u tra-t n an u tra- g t

metals grew, so did the product line. Over the years the

or g na se -c nc ng astener es gn evo ve to meet

hundreds of new design applications.

Today, nuts, studs, spacers, standoffs, access

hardware, and other components are used worldwide

by a variety of manufacturers, including producers of

te ecommun cat on, computer, me ca , automot ve, an

aerospace equ pment an systems.

2

advantagesofself-clinchingfasteners: rovi e s ron rea s in me a as in as . . mm. . . .

.

- . .

, .

.

.

Low installed costs.


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ow whyw ere

ouseself-clinchingfasteners

defined, a self-clinching fastener is anydevice, usually threaded, that when

resse nto uct e meta , sp aces t e

ost mater a aroun t e mount ng o e,

caus ng t to co ow nto a spec a y

designed annular recess in the shank or pilot of the

fastener. A serrated clinching ring, knurl, ribs, or hex

head prevents the fastener from rotating in the host

material once it has been properly inserted (see page 4).

Thus, self-clinching fasteners become a permanent part

of the panel, chassis, bracket, or other item into whicht ey are nsta e .

hey also have greater reliability and more holdingower than extruded/tapped or stamped threads. They

are used chiefly where good pullout and torque loads

are requ re n s eet meta t at s too t n to prov e

secure asten ng y any ot er met o . ven t e

sheet is thick enough to sustain tapping, it may actually

e more economical to use self-clinching fasteners

ith gaugeable threads. They can be installed during

abrication to eliminate loose hardware during final

assembly . In fact, the use of self-clinching fasteners

often will allow the use of a thinner sheet. Because ofheir compact design and low profile, they provide for a

eat appearance, too.

s a ru e, a se -c nc ng astener s ou e spec e

henever a component must be readily replaced and

here loose nuts and hardware wont be accessible.

If it appears that the attaching nuts and screws can

e reached after a chassis or cabinet is assembled,

self-clinching fasteners can be installed during metal

abrication and can simplify and expedite component

mount ng an assem y operat ons, ncu ng t ose

erformed in the field.

D E S I G N F O RM A N U F A C T U R E A N D

ASSEMBLY Self-clinchingfastenershelpdesignersmeetDFMAarameterswhichinclude:

Fewerpartstohandle.Hardwaresuchaswashers,lockwashers,andloosenutsarenolongerrequiredinfinalassembly.

Fewerassemblysteps.Sincethetaskofhardwareinstallationisdoneduringfabri-cation,thenumberofstepsrequiredforfinalassemblyisreduced.

Lesstotalassemblytime.Fewerpartsandlessstepsmeanshorterassemblytime.

Allofwhichleadtoshortertimetomarket,improvedqualitythroughassemblysimplification,andreducedoverhead.

SPECIALNOTEFORINSTALLINGINTOSTAINLESSSTEELSHEETS

Oneoftheverybasicsofself-clinchingisthatthefastenermustbeharderthanthehostsheet.Onlythenwillthefastene

performasintended.Thisisparticularlychallengingwheninstallingfastenersintostainlesssteelsheetmetal.

Ifyourapplicationrequiresthatthefastenerclinchesintostainlesssteel,besureyouusethefastenersspecificallydesignedforthispurpose.ConsultPEMBulleitnnSSfor

informationonthsetypesoffasteners.


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he natomo se -c nc ng

Head

Component

Host Metal

Flush Mounted

Flush Mounted Hex Head ProvidesTorque Resistance

Direction ofInstallation Force

Host Metalows n o n ercu

Ribs ProvideTorque Resistance

us oun e

rec on o ns a a on o rce

Host Metalold Flows into

Undercut

rec on oInstallationForce

Serrated ClinchingRing ProvidesTorque Resistance

Back Tapered Shank

omponent

typicalself-clinchingnut

typicalself-clinchingstud

typicalself-clinchingstandoff

4


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asict esofsel -c nc ngasteners

nuts: uts w t t rea strengt sgreater t an m stee screws

are common y use w erever

strong internal threads are needed

for component attachment or

fabrication assembly.

studs: Externally threadedfasteners which are used where

t e attac ment must e pos t one

before being fastened.

spacers&standoffs:Used where it is necessary to stack

or space components away from thepanel. Thru-threaded or blind types

are generally standard.

ushfasteners: Whennsta e , t ese asteners are

completely ush within the sheet.

Many times these fasteners are

installed into a at sheet so that the

fasteners will not interfere with later

bending and forming operations.

oatingnuts: This fastenercompensates for mating hole

misalignment by having a oating

t rea e e ement.

threadedaccessar ware: Generally used on

enclosures where the screw must

remain with the door or panel.

lockingfasteners: Providea prevailing torque locking feature

to restrict the rotation on the

screw un er a verse con t ons

of vibration. Locking features may

nc u e meta or p ast c types.

non-threadedfasteners:Allow for quick assembly or removal

of components without the need

for screws or additional fastening

hardware.

concealed-head: Installedinto milled, blind holes so that

one s e o t e pane rema ns

unmarred. Studs and standoffs

are genera y ava a e n t e

concea e - ea type.

blind: Have closed ends thatlimit screw penetration and are

useful for protecting internal

components from damage by

inadvertent insertion of extra long

screws. rea s are a so protecte

from damage and foreign matter.

rightangle: Provide youwith strong right angle attachment

points in sheets as thin as .040/

1mm. These fasteners are a

cost-effective replacement for:

bent edge tabs; bent center tabs;

bent anges; angle brackets; tack

we s; an oose ar ware.

cabletie-mount: Self-

clinching tie-mounts are designedto provide secure attachment

points for mounting wire to

electrical chassis or enclosures

without the problems associated

with traditional mounting methods.

sheetjoiningfastener:a self-clinching fastener that joins

two sheets of metal. The fastener

installs smooth with the top sheet,

and ush or sub-ush with the

bottom sheet.

CUSTOMDESIGNS

Sincethereareagreatmanytypesofstandardself-clinchingfastenersavailable,itisusuallypossibletochooseonetome

yourdesignrequirement.Therearetimeshoweverthatacustodesignedandmanufacturedfastenerisnecessary.Ifthisisth

case,PennEngineeringcanassistyouwithyourrequirementtprovideyouwiththebestsolutiontoyourdesign.


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qualityofself-clinchingfasteners

n order request comes to the desk of

the buyer or procurement individual with

the words PEM or equivalent written

next to a specification for self-clinching

fasteners. Although a review of the manufacturers basic

spec cat ons w un ou te y turn up a s opp ng st

of equivalents, a purchase made on the basis of lower

rice alone may prove

more costly in the long

un.

here are significant

ar at ons n t e

mater a s use ,

manu actur ng process,

quality controls and

component dimensions

hat make the same

roduct, made by

different manufacturers,

ery different from one

anot er.

Wire stock is used for the manufacture of many self-

clinching fasteners. Basic blanks are formed on cold

headers or cold formers; subsequent operations such as

p erc ng, r ng, tapp ng, t rea ro ng, an s ott ng may

e requ re .

Self-clinching fasteners are also made from free-

machining, cold-drawn, low-carbon bar stock, a variety

of free-machining and cold-drawn stainless steels,

aluminum and phosphor bronze. They are formed on

automatic bar machines and generally have secondary

operations such as slotting, tapping or lock forming.

n s ng operat ons suc as eat-treat ng an p at ng

are equa y sop st cate , an qua ty contro measures

must be monitored throughout the manufacturing

process.

With so many manufacturing variables to control, there

are several quality areas which must be examined before

choosing the manufacturing of self-clinching fastener for

your app cat on.

ese nc u e:

installedcost...thebottomline

e es ra o us n se -c nc n

,

o era rue c ureo cos . n e ra

,

t ecosto mater a s a oran

over ea mus e ac ore n o e

accura e com ar son w e na

-

astener.Re ectsan s o a e ueto

cos s,so ecer a n a e

ouren neer n s ec ca ons.

DIMENSIONALTOLERANCES: se -c nc ng astener requ res very t g t to erances to max m ze t s per ormance. n apart that is specified with a dimension .010 / 0.254 mm a variation of only .002 / 0.051 mm can make a 20% difference.

THREADFIT:A part may be specified because it meets one or more government specifications for thread tolerances. Ifequivalents are considered, be sure that they meet the same specifications.

PREVAILINGTORQUE:Be sure that parts meet the prevailing locking torque specifications required.

HEATTREATMENT:This is a very critical quality area. Improper heat treatment can cause a fastener to fail during or afternsta at on. mproper temper ng can cause astener r tt eness caus ng t e astener to crac ; na equate treatment can cause

fasteners to be so soft that they are literally crushed during installation.

PLATING:Plating standards set limits for preparation of the metal, plating thickness, adhesion, rust corrosion protection,ours o sa t spray test ng, an ot er operatons. poor y p ate part w m n s t e appearance an per ormance o your

final product.

PERFORMANCE:The fasteners should be tested to meet the manufacturers published performance data. In addition toas c per ormance test ng, e sure t e astener a so meets your requ rements or v rat on res stance, t rea oc ng, eat,

an e ectr ca c aracter st cs.

QUALITYCONTROL:Ensure the fastener manufacturer is ISO 9001 / QS 9000 compliant. This will help assure that all thea ove crter a s e ng met.

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reliabilitnserv ce

ofaself-clinchingfastener

e re a ty o a se -c nc ng astener n

service depends on many factors, beginningith a properly sized hole, the thickness and

hardness of the host panel,

proper installation and design of the

fastener, and the application where the

fastener is used.

ere are t ree tests app ca e to a

se -c nc ng astener to eterm ne ts

reliability in service. The first, called torque-

out, determines the fasteners ability to

resist rotation within the panel. This test

often is made at the head of the fastener

o ten w t va ues excee ng t e u t mate tors ona

strength of the mating screw or nut.

A second reliability measure is pushout.

Pushout values indicate the axial resistan

of a fastener to remove it from the sheet

opposite to the direction from which it wa

nsta e , an s ou e roug y 5 to 10%

of the force used to install the fastener.

A final test is pull-through.(1) Pull-through

is the resistance of a fastener to pulling

through the metal sheet when a clamping

torque is applied.

properlysizedhole

sheetthickness

sheethardness

properinstallation

qualityoffastener

(1) Pull-through generally applies only to self-clinching studs and standoffs and is not shown in this chart.(2) See special note about installing into stainless steel on page 3.

ThreadTestSheetMaterial

Size 5052-H34Aluminum Cold-rolledSteel 300SeriesStainlessSteel(2)

Installation Pushout orque-out Installation Pushout Torque-out Installation Pushout orque-ou

lbs.) kN) lbs.) N) i n.lbs.) Nm) lbs.) kN) lbs.) N) i n.lbs.) Nm) lbs.) kN) (lbs.) N) i n.lbs.) N

2-56 M2 1500-2000 6.7-8.9 90 00 10 1.13 500-3500 11.2-15.6 125 550 15 1.7

4-40 M3 1 500-2000 6.7-8.9 90 00 10 1.13 500-3500 11.2-15.6 125 550 15 1.7 000-5000 13-22 165 725 17 1.

6-32 M3.5 2500-3000 11.2-13.5 95 00 17 1.92 000-6000 13.4-26.7 130 570 0 2.3 000-7000 22-31 170 750 24 2.

8-32 M4 2500-3000 11.2-13.4 105 70 23 2.6 000-6000 18-27 145 645 5 4 000-7000 22-31 180 800 7 4.

10-32 M5 - 11.2-15.6 110 . - 18-38 180 . - - 1025 .

1/4 M6 4 000-7000 18-32 60 1580 90 10.2 6000-8000 27-36 400 1760 150 17 9000-11000 40-48 50 000 150 1

5/16 M8 4000-7000 18-32 80 1570 120 13.6 6000-8000 27-36 420 1870 165 18.7

Generalpushoutandtorque-outvaluesforPEMself-clinchingnuts.(1)

(unifiedandmetricdata)


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ast,simpleinstallationsavestimeandmoneyontheassemblyline.

n just three easy steps, self-clinching fasteners

can be installed with any parallel acting pressthat can be adjusted to optimum installation forces.

nstallationrocedure

Specialconsiderations...

1.Mounting holes may be punched, drilled, or cast;they should not be chamfered or have broken edges in

excess of .005 / .127 mm. Hole tolerances of +.003,

-.000 / +0.08 mm must generally be held. The fastener

should be installed on the punch side if the sheet is .09

/ 2.29 mm or thicker because of the piercing break-to-

die diameter. Holes pierced in sheets thinner than .09 /

2.29 mm may ave asteners nserte on e t er s e. n

all cases, the manufacturers recommended minimum

centerline of hole to edge of sheet distance should be

observed. No deburring or countersinking is required.

2.Installation results in a flush surface on one side of thepanel. Conversely, staked or crimped fasteners require

special counterboring to obtain a one-sided flush surface.

3.When installing, the most important criterion is thatthe fastener must be squeezed into place. A hammer

blow or impact does not allow sufficient time for the

sheet material to flow into the recesses of the shank and

un ercut.

4.Because the installation equipment generates no

excess noise or pollution, the fasteners can be installedanywhere in the production process. No special facilities,

ventilation equipment, or safety procedures are required.

5.When installed using the recommended squeezingforce (depending on the size of the fastener and

hardness of the sheet metal), there is little or no distortion

of the sheet or damage to the finished surface. Fasteners

generally should be installed after plating, finishing, or

ano z ng. t oug , w t a proper p at ng process, t ey

can be installed before plating.

as eners uare n oa rev ous

unc e r e orcas o e.

,

.

.

na ns a ema n ece rom

.

fastenerinstallationDOs...DO provide mounting hole of specified size for each fastener.

make certain that shank (or pilot) is within hole before

applying installation force.

apply squeezing force between parallel surfaces.

apply sufficient force to totally embed clinching ring around

ntire circumference and to bring shoulder squarely in contact

with sheet. For some fasteners installation will be complete when

the head is flush with the sheet.

fastenerinstallationDONTs...DONTinstall steel or stainless steel fasteners in aluminumpanels before anodizing or finishing.

DONTdeburr mounting holes on either side of sheet beforeinstalling fastenersdeburring will remove metal required for

clinching fastener into sheet.

DONTinstall fastener closer to edge of sheet than minimumdge distance indicated in dimension tablesunless a special

fixture is used to restrict bulging of sheet edge.

DONTover-squeeze. It will crush the head, distort threads,and buckle the sheet. Be certain to determine optimum installation

force by test prior to production runs.

DONTattempt to insert fastener with a hammer blow under any circumstances. A hammer blow wont permit the

sheet metal to flow into the back tapered shank.

DONTinstall screw in the head side of the fastener. Installfrom opposite side so that the fastener load is toward the sheet.

The clinching force is designed only to hold the fastener during

handling and to resist torque during assembly.

DONTinstall fastener on pre-painted side of sheet.

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nstallationroblemsandsolutions

Questions? Consult our Applications Engineering department.

problem possiblecause solution

Fastener not seated squarely

re uce o ng power.

Poor holding power fasteners fallout of panel.

Threads tight sheet buckles.

Poor holding power nut off center

o o e .

Tight threads, cracked.

Panel buckles badly with studin .040 to .059 (1 to 1.5 mm)

mater a .

Poor holding power of standoffs orstuds in panel.

Head of flush-head stud or standoffcups.

Poor holding power.

Edge of panel bulges.

Punch and anvil faces are not

para e .

Panel cocked during installation.

Inadequate installation force. Panel too hard for fastener

material.

Countersunk hole in panel.

Fastener over-squeezed.

Oversize mounting hole.

ut s coc e n o e an s ears

side of hole when installed.

Shank length extends throughsheet.

Lack of countersink in anvil.

o e n anv too arge orchamfered.

Punch diameter too small or notar an at.

Die side of panel thicker than

.093/2.36mm may have holetoo large for fastener due tonecessary punch and die

c earance.

Mounting hole violates specified

minimumn edge distance.

ut s over-squeeze .

Ensure that punch and anvil areflat and parallel and hard. Ensure that large panels are held

perpendicular to punch and anvi

Seat fastener against shoulder

by applying more force or

changing shut height of press. Specify appropriate fastener

material for sheet hardness, i.e.stainless steel (see note on page 3)

Do not countersink or deburr hol

Reduce installation force.

Punch or drill hole to specified

dimensions. Check that shank of nut is

squarely in hole before squeezin

Choose fastener with proper

shank length for sheet thickness

rov e counters n n anv tospecified dimensions.

se anv w t o e per cata og

dimensions.

Punch must be larger than head

of stud or standoff and preferab

equal to anvil diameter.

unc o e un er s ze an ream

to catalog dimensions or changtooling to punch from opposite

side of panel.

estra n pane or rac et n

fixture during installation or movmount ng o e away rom e ge.

Reduce installation force if possibl


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otherconsiderations

AUTOMATEDASSEMBLY

Since all self-clinching fasteners must be squeezed into place, any press or vise that

provides the necessary parallel force may be used to install them.

A PEMSERTER automated press should be considered for high volume installations.

PEMSERTER presses are specifically designed to feed self-clinching fasteners

automatically into punched or drilled holes in sheet metal, seating them correctly

with a parallel squeezing force. Feeding rates are five to six times faster than manual

insertions, and installation force is adjustable to compensate for variations in thickness

an ar ness o t e s eet an t e e g t o t e asteners.

Our equipment capabilities now incorporate smart tooling andsoftware, automation, robotics integration, and in-die installation

with the PEMSERTER in-die fastener feeding system which brings

new dimensions to stamping capabilities and incorporates the latest

technologies to deliver the performance that is needed to compete in

t e g y compet t ve stamp ng n ustry. t e m nates t e secon ary

operations typically required for fastener insertion, thus reducing overall

a or costs, mprov ng part qua ty an ramat ca y mprovng pro uct

through put.

FASTENERSFORNON-

DUCTILEMATERIALS

With the arrival of P.C. boards, plastics and

other fabricated materials, a need emerged for

a fastener which would offer the same benefits

as self-clinching fasteners but work effectively

in these non-ductile materials. To address this

requirement, PennEngineering

offers PEM broaching fasteners

an ee ast SMT surface mount

asteners.

A broaching fastener is any knurled

shank fastening device that is

pressed into a punched or drilled hole to

provide a strong threaded attachment point

in a non-ductile material. Specially formed

axial grooves around the shank of the fastener

broach or cut into the material, creating a

firm, interference-type fit, resistant to

rotat ons.

ee ast SMT fasteners mount

to P.C. boards in the same manner as

other surface mount components

prior to the automated reflow solder

process.

Regardlessoftheself-clinchingfastener

youchoose,itisalwaysrecommended

thatyouobtainsamplestodoyourowntesting.

Theintegrityofyourproductdependsontheperformanceandqualityof

thesefasteners.

10


13/16

answersothetenmost

commonlyasked uestionsaboutself-clinching as eners

QDoestheshapeoftheself-clinchingfastenerchangeduringinstallation?A o, the fastener does not deform in any way. Thereis no flaring, crimping, swaging, peening or rivetingnecessary._ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

QWhatholdsthefastenerinthesheet?A he squeezing force on the fastener causes thes eet mater a eneat t e ea to co ow nto t e

back-tapered shank or undercut of the fastener securelylocking it in place._ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

QDoIneedspecialequipmenttoinstallself-clinchingfasteners?

A o. Self-clinching fasteners are installed usingany type of parallel acting press which will squeeze thefastener in place._ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

QWontthesefastenersfallout,twistout,orspinintheirmountingholesifItightendowntoohard?

A o. yp ca torque-out va ues are genera y qu tehigh compared to the rotational force that will be puton them. In fact, for most quality self-clinching nuts, thescrew will fail before the nut rotates in the material._ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

QCanIinstallaself-clinchingfastenerwithahammerbloworsimilarforce?

A o, a self-clinching fastener must be installedus ng a squeez ng act on. qu c mpact nsta at on

will not allow sufficient time for the sheet material to coldflow._ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

QIwouldliketoreplacesomeoftheweldedfastenersInowuseinmystainlesssteelfabrications.Isthereaself-clinchingfastenerthatwillgointoastainlesssteelsheet?

A es. Self-clinching fasteners for stainless steelapplications are available. These fasteners are generallymade from specially hardened stainless steel and willinstall into sheets up to HRB 88 in hardness.

QWhenusingself-clinchingfasteners,whataremypanelrequirements?AGenerally, there are two basic requirements.

irst, the panel must be a ductile material softer thanhe fastener which is going into it. Second, the panel

must meet the minimum sheet thickness required by tharticular fastener. Some self-clinching fasteners cane installed into sheets as thin as .020/0.51mm, but

generally .030/0.76mm or .040/1mm is the minimums eet t c ness necessary._ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

QIsthereamaximumsheetthicknessIshouldbeconcernedwithbeforespecifyingself-clinchingfastenersAGenerally, there is no specified maximum thickneor sheets. However, because of their special design anunction, a few fastener types do specify a thicknessange which includes a maximum._ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

QInoticesomeofthefastenershaveahexagonalshapedhead.DoIhavetopunchahexagonalmountingholetoinstallthese?

ANo. All self-clinching fasteners are installed intoa round punched or drilled hole. A hexagonal head wilcause the sheet material to cold flow around the head

rov e g torque-out res stance. e ex ea w lush in the sheet when installed._ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

QCanIinstalltheseblind,fromoneside,ifIdonthaveaccesstobothsidesofthesheet?

AGenerally, you must have access to both sidesof the sheet to properly install self-clinching fasteners.

owever, there are some 1/4/M6 or larger nuts whichcan be drawn in from one side using an impact-torque

rench. For information on blind threaded inserts for onsided access installation go to www.pemnet.com.


14/16

anvil- n nsert, e t er so or o ow, w c s use on t e un ers e o apane to res st t e nsta aton orce.

blind- oe , usua y t rea e , w c s open rom ony one en .

broaching- e act o cuttng a s ape n any o ect y usng a man re os m ar s ape. s app e to asteners, t e way a nure s an roac es

ts way nto t e mount ng o e.

captive- e a ty o a astener to reman secure y attac e to a pane .

captivescrew- ee: pane astener.

chamfer- eve e e ge or corner.

coldflow- e movement o a uct e mater a un er pressure.

concealed-head- type o astener w c , w en nsta e , s competeyen w en vewe rom t e reverse s e.

ductile- eta w c s not r t te an can e eas y orme or ent.

floating- e a ty o a astener to move n a rect on para e to t emount ng pane an a ow or mat ng o e m sa gnment.

flush- he ability of a fastener to be contained completely within thethickness of a panel. Also refers to the absence of a protrusion above thesurface of the panel.

head-The portion of a fastener which forms its largest diameter.

installationforce-A term expressed in pounds, tons, or newtons appliedxially to a self-clinching fastener to achieve proper installation.

interferencefit- he insertion of one member into another whose diameteris slightly smaller than the part being inserted.

knurledclinchingring-The displacer portion of a fastener which hasorrugations and is used to develop torque resistance when installed in sheet

metal.

lockingelement-A device employed to restrict rotation of a threadedmember while operating in adverse environments, such as vibration andtemperature. The nut-locking element provides prevailing locking torque to themating screw.

minimumdistance-The minimum distance from the center of a fastenermounting hole to the nearest edge of a panel which will keep the edge fromdeforming. This distance may be reduced by suitable fixturing or increasingthickness of panel material.

minimumsheetthickness-The thinnest section of a panel, usuallymeasured in thousandths of an inch or millimeters, into which a fastener may

properly be installed. The same fastener may be installed in panels having anythickness greater than minimum.

mountinghole-A properly-sized round opening in a panel to receive theshank of a self-clinching fastener.

panelfastener-A threaded screw which is held captive to a panel andwhich, when disengaged from its main nut, remains fixed to that panel.

pin-A captive post that extends from a panel.

plungerassembly-A spring-loaded device used for latching or indexingpurposes.

positivestop- v sua n cat on t at t e proper ept o penetrat on ot e nure rng as occurre or w en t e ea s n contact w t t e topsur ace o t e pane . ynonym: s ou er.

pull-through- e resstance o a astener to a orce app e n t e samerecton to w c t was nsta e .

punch- mova e nsert, e t er so o o ow, w c app es an nsta at o norce to t e top o t e astener.

pushout- e orce requre to remove a astener rom a pane n a rect onoppos te to t e way rom w c t was nsta e . ote: us out s expresse npoun s or newtons.

rockwellhardness- reatve measure o ar ness. oc we cae suse or ar mater a s, oc we or soter mater a s, suc as s eet meta .

self-clinching- e met o y w c a astener s securey attac e to as eet o uct e mater a y causng t e mater a to co ow un er pressurento an annuar recess o t e astener t ere y securey oc ng t n pace.

self-locking- oc ng e ement, orme as an ntegra part o a astener,w c prov es orce to restrc t t e rotat ona movement o a t rea e mem er.

shank- e por ton o a astener, w c s s g t y sma er t an t e astenersmounting hole and provides a positive location for the fastener in the hole. Ashank also incorporates an annular groove which becomes filled with panelmaterial as the fastener is installed, and the retention of this material providespushout resistance.

shanklength-The actual length of that portion of a fastener which isembedded in the panel material.

shoulder-The surface area of a fastener which contacts the top surface ofthe sheet material. See: positive stop.

spring-loaded- device having a separate moveable component that is

biased in one direction by a spring.

standoff-A tubular device, usually threaded, for spacing or stackingomponents.

stud-A male threaded captive post that extends from a panel.

swaging-An operation whereby a reduced diameter of a fastener isdeformed to secure it to a panel. Note: the antonym of swaging is self-clinchingwhere the panel material is caused to deform.

threadclass- measure of clearance or fit between the screw and the nuttaken at the pitch diameter.

threadedinsert-A threaded device which is installed in a panel material.

throughhole- hole, threaded or unthreaded, which transverses theentire length of a part and is usable from either end.

tolerance-The absolute amount of maximum or minimumdimensional deviation allowed that will not affect the performance of amechanical part.

torque-out- he amount of torque necessary to spin the fastener out of thesheet. This is torque applied to the fastener. No axial load is applied.

torque-through-The amount of torque necessary to fail the fastener inxial load.

undercut-The reduced diameter of a fastener which receives sheetmaterial when a fastener is installed. Depending on the type of fastener, maybe rectangular or back tapered in shape.

glossaro terms

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PEM fasteneridenticationtrademarks

o help you identify genuine PEM brand fasteners, most are marked by one of our registered trademarks.

Genuine PEM brand fasteners can only be purchased from one of our authorized worldwide distributors. For

a complete list of these distributors, check our web site: www.pemnet.com or call us at our main office.

TwoGrooveonNuts,Standoffs,andPlungers

RecessedDimpleonStuds,Pins,PanelFasteners,KEYHOLEandSNAP-TOPStandoffs

PEMStamponNutsandHYBRIDPanelFasteners

BlueNylonLockingElementonPEMHEXLockingNuts

DoubleSquaresonFloatingFasteners ThePEM300IdenticationMarks


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PEM Self Clinching Fasteners

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