ISO INTERNATIONAL STANDARD 4026 Third edition 2003-12-01 Hexagon socket set screws with flat point Vis sans tete a six pans creux, a bout plat Reference number ISO 4026:2003(E) @ ISO 2003 ISO 4026:2003(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies technical committees. Each member body interested in a subject for which a technical committee has been non-governmental, in liaison with IsO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. isO shall not be held responsible for identifying any or all such patent rights. ISO 4026 was prepared by Technical Committee ISO/TC 2, Fasteners. This third edition cancels and replaces the second edition (isO 4026:1993), which has been technically revised @ ISO 2003All rights reserved ii INTERNATIONAL STANDARD ISO 4026:2003(E) Hexagon socket set screws with flat point 1 Scope This International Standard specifies the characteristics of hexagon socket set screws with flat point and threads from M1,6 up to and including M24 and of product grade A. If, in special cases, specifications other than those listed in this International Standard are required, they should be selected from existing International Standards, e.g. ISO 261, ISO 898-5, ISO 965-2, ISO 3506-3 and ISO 4759-1. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated (including any amendments) applies. IsO 225, Fasteners Bolts, screws, studs and nuts Symbols and designations of dimensions ISO 261, iSO general-purpose metric screw threads - General plan similar threaded fasteners not under tensile stresses ISsO 965-2, ISO general purpose metric screw threads - Tolerances - Part 2: Limits of sizes for general purpose external and internal screw threads Medium quality screwthreads IsO 3269, Fasteners —Acceptance inspection similar fasteners not under tensile stress ISO 4042, Fasteners Electroplated coatings ISO 4759-1, Tolerances for fasteners Part 1: Bolts, screws, studs and nuts — Product grades A, B and C Iso 6157-1, Fasteners - Surface discontinuities Part 1: Bolts, screws and studs for general requirements Iso 8839, Mechanical properties of fasteners Bolts, screws, studs and nuts made of non-ferrous metals Iso 8992, Fasteners —General requirements for bolts, screws, studs and nuts IsO 10683, Fasteners Non-electrolytically applied zinc flake coatings ISO 23429, Gauging of hexagon sockets @ ISO 2003All rights reserved ISO 4026:2003(E) 3 Dimensions See Figure 1 and Table 1. Symbols and designations of dimensions are specified in IsO 225. 120 °a 90. Permissiblealternativeformofsocket For broached sockets which are at the maximum limit of size, the overcut resulting from drilling shall not e/2 exceed 1/3 of the length of any flat of the socket which (e/2)/3 is e/2. a The 120° angle is a requirement for short-length screws of nominal length, l, situated in the shaded areas in Table 1. b The 45° angle applies only to the portion of the point situated below the root diameter of the thread. c Incomplete thread u < 2P. Figure 1 2 @ ISO 2003 - All rights reserved ISO 4026:2003(E) Table 1 -Dimensions Dimensions in milimetres Thread (d) M1,6 M2 M2,5 M3 M4 M5 M6 M8 M10 M12 M16 M20 M24 pa 0,35 0,4 0,45 0,5 0,7 0,8 1 1,25 1,5 1,75 2 2,5 8 max. 0,80 1,00 1,50 2,00 2,50 3,5 4,0 5,5 7,00 8,50 12,00 15,00 18,00 dp min. 0,55 0,75 1,25 1,75 2,25 3,2 3,7 5,2 6,64 8,14 11,57 14,57 17,57 dt min. ~ Minor thread diameter eb, c min. 0,809 1,011 1,454 1,733 2,303 2,873 3,443 4,583 5,723 6,8