Standard components on drawings: To simplify working drawings, is it acceptable to list standard off-the-shelf parts (fasteners, bearings, fittings) in a parts list or note rather than fully redrawing them?

Difficulty: Easy

Correct Answer: Correct

Explanation:


Introduction / Context:
Working drawings should be as simple and clear as possible. Redrawing every standard component clutters sheets and adds no value. Instead, referencing catalog or standard specifications (e.g., ISO, ANSI, ASME) keeps the focus on custom features while ensuring the correct off-the-shelf item is procured.



Given Data / Assumptions:

  • Standard hardware is available with clear part numbers or standard codes.
  • The drawing set includes a bill of materials (BOM) and notes.
  • Manufacturing and purchasing will use the BOM/notes to source parts.


Concept / Approach:
Instead of drafting detailed geometry for a standard bolt, simply specify size, thread, material, property class, finish, and relevant standard number. The assembly drawing may show simplified outlines for fit and clearance, but exact geometry is delegated to the standard reference.



Step-by-Step Solution:

Identify standardized parts (fasteners, bearings, keys, seals).List them in the BOM with specification: standard number, size, material, finish.Use simplified symbols or placeholders in views to maintain clarity.Ensure notes cover any special installation requirements (torque, lubrication).


Verification / Alternative check:
Supplier catalogs and standards provide exact details; procurement and QA can verify conformance by part number rather than by redrawn geometry, confirming that listing is effective and accepted practice.



Why Other Options Are Wrong:

Incorrect: Redrawing every standard part is unnecessary and error-prone.Only fasteners / only assemblies: The principle applies widely to standardized bought-out items in both detail and assembly contexts.


Common Pitfalls:
Omitting critical callouts (e.g., thread pitch, tolerance class); mixing incompatible standards; forgetting to update the BOM when a standard changes.


Final Answer:
Correct

More Questions from Working Drawings

Discussion & Comments

No comments yet. Be the first to comment!
Join Discussion