DFTG1329 Standards are published documents that set up rules, specifications and protocols designed to ensure consistency, compatibility and reliability of products, materials and services. Standards are established by consensus and their implementation is not mandatory but they are generally adopted to prove quality and promote trade. Standards are put to use through conformity assessment. Conformity assessment is defined as any activity concerned with determining directly or indirectly that relevant requirements are fulfilled (ISO/IEC Guide 2:2004). International Organization for Standardization ISO is a federation of nearly 150 national standards bodies, one from each country. ISO's work results in international agreements which are published as International Standards and other types of ISO documents. U.S. representative and also a founding member of ISO is: American National Standards Institute ANSI is an organization of standard developers, trade associations and professional and technical societies and there are nearly 1000 members who represent almost every US industry sector and address variety of issues. Each member brings together a range of individuals and organizations with broad points of view. ANSI itself does not develop standards, it provides neutral forum and accredits others to do the developing, both nationally and internationally. Accreditation is defined as the procedure by which an authoritative body gives formal recognition that a body or person is competent to carry out specific tasks (ISO/IEC Guide 2:2004). There are more than 220 ANSI-accredited standards developers including organizations like ASTM International, Underwriters Laboratories, Inc., NFPA International, ASME International, SAE etc. 1
DFTG1329 American Society of Mechanical Engineers ASME ASME produces approximately 600 codes and standards covering technical areas such as fasteners, plumbing fixtures, elevators, pipelines, and power plant systems and components. ASME's standards are developed by committees of subject matter experts using a consensus-based process. ASME standards are cited as tools to meet objectives and are therefore voluntary, but they can be incorporated into a legally binding business contract or regulations enforced by an authority having jurisdiction, such as a federal, state, or local government agency. ASME's standards are used in more than 100 countries and have been translated into numerous languages. Boiler and Pressure Vessel Code (BPVC) is the largest ASME standard, both in size and in the number of volunteers involved in its preparation. The BPVC provides rules for the design, fabrication, installation, inspection, care, and use of boilers, pressure vessels, and nuclear components. The code also includes standards on materials, welding and brazing procedures and qualifications, nondestructive examination, and nuclear in-service inspection. American Society for Testing and Materials ASTM ASTM International develops and publishes technical standards for materials, products, systems and services. Over ten thousand such standards are implemented globally. It was formed in 1898 when a group of engineers got together to address frequent rail breaks. Their work led to standardization on the steel used in railroad construction. Examples of ASTM standards: A563 Specification for Carbon and Alloy Steel Nuts A751 Test Methods, Practices, and Terminology for Chemical Analysis of Steel Products B695 Specification for Coatings of Zinc Mechanically Deposited on Iron and Steel F436 Specification for Hardened Steel Washers F1470 Practice for Fastener Sampling for Specified Mechanical Properties and Performance Inspection F1789 Terminology for F16 Mechanical Fasteners F2329 Specification for Zinc Coating, Hot-Dip, Requirements for Application to Carbon and Alloy Steel Bolts, Screws, Washers, Nuts, and Special Threaded Fasteners G101 Guide for Estimating the Atmospheric Corrosion Resistance of Low-Alloy Steels 2
DFTG1329 Underwriters Laboratories UL LLC UL LLC is an independent and non-profitable product safety certification organization that has been testing products and writing safety standards since 1894. It promotes safe living and working environments and has offices in nearly 50 countries. It evaluates more than 19,000 types of products, components, materials and systems with 21 billion UL marks appearing on 71,000 manufacturers' products each year. This is supported by 127 inspection centers, 66 laboratory, testing and certification facilities and a staff of over 6,000 people. National Fire Protection Association NFPA is a global non-profit organization that writes standards for building, processing, design, service and installation to eliminate death, injury and material loss due to fire, electrical and related hazards. It is responsible for over 300 codes, such as: NFPA 1 - Fire Code (provides requirements to establish a reasonable level of fire safety and property protection in new and existing buildings). NFPA 54 - National Fuel Gas Code (the safety benchmark for fuel gas installations. NFPA 101 - Life Safety Code (establishes minimum requirements for new and existing buildings to protect building occupants from fire, smoke, and toxic fumes). NFPA 704 - Standard System for the Identification of the Hazards of Materials for Emergency Response: (defines so called "fire diamond" used by emergency personnel to quickly and easily identify the risks posed by hazardous materials). National Electrical Code NEC or NFPA 70 The standard for the safe installation of electrical wiring and equipment in the United States. Addresses the installation of electrical conductors, equipment, and raceways. 3
DFTG1329 American National Standard Drafting Manual ANSI Y14 describes engineering drawing standards in following sections: Y14.1 Drawing sheet size and format. Y14.2. Line conventions and lettering. Y14.3. Multi and sectional view drawings. Y14.4. Pictorial drawing. Y14.5. Dimensioning and tolerancing. Y14.6. Screw threads. Y14.7. Gears, splines and serrations. Y14.7.1. Gear drawing standards. Y14.9. Forgings. Y14.10. Metal stampings. Y14.11. Plastics. Y14.14. Mechanical assemblies. Y14.15.a. Interconnection diagrams. Y14.15. Electrical and electronics diagrams. Y14.17. Fluid power diagrams. Y14.26.3. Dictionary of terms for computer-aided preparation of product definition data. Y14.32.1. Chassis frames: passenger car and light truck. Y14 report: Digital representation of physical object shapes For example, ANSI/ASME Y14.1 defines paper sizes. Cutting a sheet in half would produce two sheets of the next smaller size, until the 8½ in 11 in (letter) size which it assigned size A. ISO 216 specifies international standard paper sizes used in most countries in the world today. The standard defines the "A" and "B" series of paper sizes, the most commonly available being size A4. 4
ANSI and ISO standard sheet sizes 5
Standard line types: Standard Abbreviations: 6
ASME Y14.6 2001, Screw Thread Representation ASME Y14.6-2001, Screw Thread Representation is a standard for depicting screw threads on drawings and other documents. It does not cover engineering and manufacturing specifications for screw threads. Few examples of what is covered, given through the latest revision (2001) changes: -the metric standard (Y14.6aM-1981) and the decimal inch standard (Y14.6-1978) are combined. It was updated in accordance with the latest issue of ASME B1 series. -for decimal inch sizes you should no longer put a zero in front of the decimal point. For example, under the old standard it would be 0.750, but in this revised standard it is.750. -for fractional decimal equivalents, you should reduce a fourth digit zero to three decimal places. For example,.7500 should be reduced to.750. -screw numbers may be used to designate nominal thread size. However, fractional and decimal sizes are still permitted. -thread gaging systems 21, 22 and 23, based on ASME B1.3M for inch and metric (UN, UNR, UNJ, M, and MJ), have been added to thread callouts. System 21 is the lowest level of gaging, system 22, the middle level, and system 23, the highest level. Generally if systems 22 and 23 are specified it will require new gaging equipment. This standard is covered in Section 4.14 of the Genium Drafting Manual. This Section, titled Screw Thread Representation, provides the following: -Clear explanations and figures showing screw thread representation as covered in the standard. -A clear definition and discussion of gaging systems 21, 22, and 23. -A table showing the largest hole size for a specific fastener hex head size. -Easy to use GD&T formulas for position. -A discussion showing why a projected tolerance zone should be used. -A table of thread sizes for both inch and metric screw designations. -The DoD is now relying on the ASME B1 series for thread performance specifications, leaving the responsibility for design, processes, quality control, etc., to the thread manufacturer. These aspects are covered in the Genium Drafting Manual, Section 4.15 Screw Thread Design Considerations For drafting personnel, the major purpose of this standard is to show how to place and draw the three methods of screw thread representation (simplified, schematic, and detailed) and also how to state thread requirements on engineering drawings. A few of the specifics covered: Showing and dimensioning the thread runout. Drawing tapered threads, specifically making sure that they are tapered 3 from the axis. Drawing thread inserts, dimensioning a thread relief, specifying a thread callout, the thread series and class letter symbols, coating of threads and pipe thread callouts. 7
METHODS OF REPRESENTING SCREW THREADS ON A DRAWING: Detailed: Schematic: 8
Simplified: 9
Simplified blind internal thread representation 10