Drawing Standards

Drawing Standards

Introduction

• Definition of Standards: Standards are sets of rules governing how technical drawings are represented.

• Purpose of Drawing Standards: Drawing standards are employed to ensure that drawings convey the same meaning to all readers.

Engineering Drawing Standards

• Necessity of Standards: Engineering drawings must adhere to national and international standards for clear communication.

• Language of Drawing: Standardization facilitates communication among individuals from different countries and linguistic backgrounds.

Major Organizations Involved in Standardization

ISO (International Standards Organization)

• ISO Standardization: ISO standards are dynamic and evolve with engineering practices.

• ISO 128: An international standard detailing general principles for the presentation in technical drawings, focusing on graphical representation.

• ISO 1101: Provides basics and fundamentals for geometrical tolerancing.

ASME (American Society of Mechanical Engineers)

• Formation: Founded in 1880 due to steam boiler pressure vessel failures.

• Focus: Primarily concerned with mechanical engineering.

• Y14 Series Standards: These standards encompass various aspects of engineering drawings and related documents.

BS (British Standards)

• Origins: British Standards originated in 1901 as the Engineering Standards Committee to enhance manufacturing efficiency.

• Historical Standards:

  • BS 308: Established as the standard for engineering drawing in 1927 and was the first document regulating engineering drawing office practices.

  • BS 8888: Replaced BS 308 in 2000. It governs technical product documentation, geometric product specifications, and engineering drawings.

DIN (Deutsches Institut für Normung)

• DIN Issuance: DIN standards are distributed throughout the European Union as EN standards.

• Specific Standards:

  • DIN 5: Previously related to isometric projections, now replaced by ISO standard 5456.

  • DIN 6: Pertained to layout of normal views, now replaced by ISO 128.

  • DIN 406: Gives recommended practices for engineering drawings, including dimensions and tolerances.

JIS (Japanese Industrial Standard)

• Establishment: The present Standards Association was established in 1949, post World War II.

• Goal: To enhance consistency with international standards.

Components of Engineering Drawings

Major Areas of a General Engineering Drawing

1. Title Block: Contains critical identification details.

2. Grid System: Assists in locating specific points on the drawing.

3. Revision Block: Tracks changes made to the drawing.

4. Notes and Legends: Offer additional information and explanations.

5. Graphic Portion: Displays the engineering visuals.

Drawing Sheets

Standard Sizes (JIS)

• Sizes:

  • A4: 210 x 297 mm

  • A3: 297 x 420 mm

  • A2: 420 x 594 mm

  • A1: 594 x 841 mm

  • A0: 841 x 1189 mm

Drawing Space Considerations

• Types:

  • Type X: Applicable for sizes A0 to A4.

  • Type Y: Specifically for A4 size.

• Dimensions:

  • A4: Border dimensions are 10 mm (c) by 25 mm (d).

  • A3: Same dimensions as A4.

  • A2: Same dimensions as A4.

  • A1: 20 mm by 25 mm.

  • A0: 20 mm by 25 mm.

Title Blocks

• Definition: Title blocks are the initial information source in a drawing.

• Features of Title Blocks:

  • Company information (e.g., XYZ COMPANY, company address).

  • Drawing title and job number identification.

  • Responsible individuals and approval documentation.

  • Revision and other critical data fields.

Revision Blocks

• Purpose: Notes changes made to a drawing.

• Indications: Changes can be highlighted with symbols near the modified drawing sections.

Parts Lists

• Definition: Also referred to as Bill of Materials (BOM), listing all materials required to assemble the item.

Scales

• Definition: A drawing scale relates the size/distance on a drawing to the actual item.

• Example: A scale of $rac{1}{4} ext{ in} = 1 ext{ ft}$ indicates that ¼ inch on the drawing equals 1 foot of the object.

Grid System

• Usage: A drawing grid system serves to pinpoint specific locations on a drawing (e.g., point B-317 in a grid ).

Samples of Drawing Sheets and Engineering Drawings

• Specifications: Includes various notes like dimensions, tolerances, materials, and other engineering details.

Title Block Components

1. Legal Owner: Name of the document's legal proprietor (company name, logo).

2. Identification Number: Unique drawing number for identification and retrieval.

3. Date of Issue: Indicates when the document is released for use.

4. Sheet Number: Indicates the total number of sheets needed to fully describe a component.

5. Language Code: Indicates the language in which the document's text is available.

Descriptive and Administrative Data Fields

Descriptive Data Fields

• Title: Main title of the document (Mandatory).

• Supplementary Title: Optional secondary title.

Administrative Data Fields

• Responsible Department: Name of the department maintaining the document (Optional).

• Document Type: Describes the role of the document (Mandatory).

• Document Status: Current lifecycle stage (e.g., Released, Under review).

• Page Number and Total Pages: Information pertaining to pagination of documents.

Title Block Arrangement

• ISO Guidelines: Two examples of title block arrangements provided by ISO; variations exist based on user need.

• Recommendations:

  • Compactness for maximum usable space.

  • Flexibility in accommodating additional information (Legal owner, Project details).

Disadvantages of ISO Title Block Examples

• Title block recommendations favor A4 portrait formatting, limiting their effectiveness in other formats.

• Issues concerning spacing and alignment of necessary fields (e.g., company logos and names).

Additional Title Block Arrangements

• Title blocks with both mandatory and optional data fields in various configurations depending on practical needs while adhering to ISO standards.