! j I I - National Roofing Contractors Association

IntroductionThe Roof Fastener Section of the Roofing Materials Guide pro- Head Shapevides information on a variety of types of fas~en~r~ use~ for Head shapes are described variously, and manufacturers doattaching roofing materials to the deck. It IS divided Into not always agree as to nomenclature. Common terms are ~o.four separate parts depending ~n the type of deck that the 3 PhilliPs head or No.2 philliPs head, which refer to the. sizefastener is intended to be used With: (1) Steel Decks; (2) Wood of the phillips grooves; however, these terms can be combmedDecks; (3) Concrete Decks; and (4) Lightweight Concrete, with such terms as pan head, truss head, and the like, whichGypsum, or Cementitiou~ Wood ~iber Decks. No attempt describe the shape of the head. Among the more commonhas been made to categorIze the listed fastene~ b.y fastener shapes are hex-head, which has a hexagonal shape; fla.t h~ad,type (e.g., screws, staples); the name and description of t~e which is flat at the top and is designed for countersInkIng;product .should be inform~tive in this regard. Th~ data ..n pan head, which is rounded at the top; t~~s head, whichthis section has been provided the Roofing Materzals Guz.de is basically a flattened pan head. Many addlt.lonal terms areby the manufacturer and/or company that markets ItS used by manufacturers; if in doubt the Guzde user shouldfastener product. (Only companies that make and/or sell refer to their literature to determine the exact head shape.their name-brand product are listed; distributors of othercompanies' products are not included.) . Average Pullout ResistanceFollowing are explanatory notes on some of the categories £;of re q uested information in the fastener section.In 's made the sections to FM fo: Tmlus s.teel, Olsen concrete, pullout and wo?d resistance decks, tests. re erence Read-M . I "I:atena .ype ers should bear in mind . that Factory Mutual does not reportf .on fastener pullout resistance tests as a part 0 ItS approvalIn some instances, a number will be added to car~on s~eel, requirements for Standard 4470 Class I Roof Covers or Stanhardenedcarbon steel, and stainless steel. Such designations dard 4450 Class I Insulated Steel Deck Roofs. Manufacturersas 1022 for car~on steel and 3.°4 fo~ stainless steel refe~ to may request that FM conduct such tes~s or may use eithercertain properties of the steel InvolvIng strength, corrosion their own resources or other laboratories to conduct them.resistance, and alloys used. The descriptive standards for The inference should not be made that the test results pubthesedesignations are promulgated by the American Iron lished in this section were necessarily conducted by Factory& Steel Institute (AISI) and are available from AISI. Mutual.Shank'TypeMeets FM Approval Requirements as Component ofThere is a variety of terms used to describe the shanks in Class Ithreaded fasteners. Some listers simply indicate that the It should be stressed that Factory Mutual issues approvalsshank is threaded (or sPiral threaded or annular threaded) others based on an evaluation of total roof ~ystems, not for in~ividuthatthe shank has a standard thread, a buttress thread, or a al components, such as fasteners. This category only re9uestsmodified buttress thread, and still others that the threads ~re that the manufacturer indicate whether the fastener IS apsinglelead or twin lead. There are basically three types of Spl~ proved by FM as a compone.n t of a ~ystem. Readers shouldthreaded shanks: standard thread, buttress thre~d, and modl- refer to the FM Approval Guzde and Its supplef!1ents!or defiedbuttress thread. The standard thread projects top .and tails concerning the applicable roof systems m which thebottom at a 30-degree angle. The buttress thread projects fasteners are used.at the top at a 3-degree angle and at the bottom. at a30-degree angle; it is, in effect, more nearly perpendicular Warranty Available from the Manufacturerto the shank at the top. The modified buttress thread projects £;at an an Ie an here between the angles of the standard The warranty available from!he manufacturer may r~ er tothread ~d th!;uttress thread. Twin-lead threads are two a roof system warranty ~fwhlch the fastener p;oduct IS onlyseparate threads that wind around the shank, in contrast to a component. For details, contact the manu acturer.the single-lead threaded screw. Annular-threaded ~hanks consistof a series of ringed grooves rather than a spiral. Flutedshanks have wider spirals and flutes, or vertical parallelgrooves.Point TypeThe terms self-drilling and self-piercing are commonly used,sometimes in combination with other descriptions, such asPinch and gimlet. Often, the latter te~m~ are used ~ndependently.There are a variety of descriptions of pOInt types(pinch, x) that are self-drilling, that is, the point drills.a p~lothole for the screw. The term gimlet refers to a self-piercIngpoint, which, unlike the self-~rilli?g point,. punches .a holefor the threaded fastener. Nazi poznt and dzamond pornt fastenersare varieties of non-self-drilling fasteners.405