CE V S PHG 250 0910 Cop yright 2010 b y Wur th 12 0007 A C ORN NUT A nut socalled because of its shape that has a domed t op that so it pr e v ents contact with the e x ternal thr ead ALL O Y STEEL A mixtur e or allo y of or dinar y s t eel added t o o t her metals besides carbon with the speci c purpose of attaining cer tain char acteris tics such as higher s t r ength A fe w e x ceptions t o this de nition e xis t ho w e v e r so that a chr omium content abo v e 4 is no t consider ed allo y s t eel and abo v e 12 is consider ed s t ainless s t eel ANAER OBIC ADHESIVE An adhesiv e which har dens in the absence of air such adhesiv es ar e of ten used as a thr ead locking medium ANSI Stands for American N ational Standar ds Ins titute ANTISEIZE C OMPOUND An antiseize compound is used on the thr eads of fas teners in some applications The purpose of the compound depends upon the application It can pr e v ent galling of mating sur faces such compounds ar e fr equently used with s t ainless s t eel fas teners t o pr e v ent this e ect fr om occurring In some applications it is used t o impr o v e corr osion r esis tance t o allo w the par ts t o be subsequently disassembled Thir dly it can pr o vide a barrier t o w a ter penetr ation since the thr eads ar e sealed b y use of the compound ASME Stands for American Society of Mechanical Engineers ASTM Stands for American Society for T e s ting and Materials BEARIN G SURF A CE The par t of a fas tener such as the w asher face of a nut or under the head of a machine scr e w that actually comes in contact with the par t it fas tens C HAMFER A slight r ounding on the end of a fas tener or the edges of a he x nut for ease of assembly or smoo ther appear ance G ALLIN G also called SEIZIN G When tw o metals or fas teners s tick t o gether and canno t be easily loosened In tightening fas teners for e x ample pr essur e builds on thr eads as metals rub agains t each o t her and the passiv e lm pr e v enting corr osion on s t ainless may no t for due t o lack of o x y g en G A L V ANIC C ORR OSION An acceler ated degr ee of corr osion occurring when tw o di er ent metals ar e in contact with mois tur e par ticularly sea w a ter GIMLET POINT A thr eaded cone point usually having a point angle of 4550 degr ees HARDENED W ASHERS The for ce under the head of a bolt or nut can e x ceed at high pr eloads the compr essiv e yield s t r ength of the clamped material If this occurs e x cessiv e embedding and deformation can r esult in bolt pr eload loss T o o v er come this har dened w ashers under the bolt head can be used t o dis tribute the for ce o v er a wider ar ea int o the clamped material A mor e modern alternativ e is t o use a ange headed nuts and bolts HEA T TREA TMENT Heating of ten combined with cooling at contr olled temper atur es in or der t o s t r engthen and har den a fas tener HYDR OGEN EMBRITTLEMENT Hydr ogen tr apped under the sur face of a fas tener can later cause ruptur es It is gener ally associated with carbon and allo y s t eels no t s t ainless Ther e may be no e x ternal signs of corr osion befor e a br eak occurs IFI Stands for Indus trial F a s t eners Ins titute ISO Stands for International Or ganization for Standar dization J AM NUT A thinner nut that is jammed agains t ano ther nut t o pr e v ent loosening KEPS A pr eassembled nut and w asher assembly the w asher is attached t o the nut so that it w o n t fall o L O C K NUT A nut which pr o vides e xtr a r esis tance t o vibr ation loosening b y either pr o viding some form of pr e v ailing t o r q ue or in fr ee spinning nuts b y deforming andor biting int o mating par ts when fully tightened NONFERR OUS Metals without ir on Br ass and silicon br onze ar e nonferr ous s t ainless is of ten char acterized as nonferr ous but it is no t nonferr ous NYL OC NUT A t o r q ue pr e v ailing nut that uses a n y lon patented inser t t o pr o vide a locking featur e PIT C H The dis tance betw een tw o adjacent thr eads measur ed at the outside diameter of the thr eads GLOS SAR Y OF TE R M S