Technical drawing pen sizes
Technical drawing pens follow the same size-ratio principle as A series paper sizes, that is, an aspect ration of 1:√2, with the progression proceeding by folding the preceding size in two. When an A size piece of paper is folded in two it retains its proportions.
The standard sizes for technical drawings pens also differ by a factor √2, ie. 2.00 mm, 1.40 mm, 1.00 mm, 0.70 mm, 0.50 mm, 0.35 mm, 0.25 mm, 0.18 mm, 0.13 mm.
This means for example that after drawing with a 0.35 mm pen on A3 paper and reducing it to A4, you can continue with the 0.25 mm pen. (ISO 9175-1).
[edit] Related articles on Designing Buildings
- Drawing board.
- Manual drafting techniques.
- Notation and units on drawings and documents.
- Paper sizes.
- Rotring.
- Scale drawing.
- Shop drawings.
- Standard hatching styles for drawings.
- Symbols on architectural drawings.
- T-square.
- Technical drawing pen sizes.
- Types of drawing.
- Types of paper.
- Technical drawing.
- Working drawings.
Featured articles and news
Shortage of high-quality data threatening the AI boom
And other fundamental issues highlighted by the Open Data Institute.
Data centres top the list of growth opportunities
In robust, yet heterogenous world BACS market.
Increased funding for BSR announced
Within plans for next generation of new towns.
New Towns Taskforce interim policy statement
With initial reactions to the 6 month policy update.
Heritage, industry and slavery
Interpretation must tell the story accurately.
PM announces Building safety and fire move to MHCLG
Following recommendations of the Grenfell Inquiry report.
Conserving the ruins of a great Elizabethan country house.
BSRIA European air conditioning market update 2024
Highs, lows and discrepancy rates in the annual demand.
50 years celebrating the ECA Apprenticeship Awards
As SMEs say the 10 years of the Apprenticeship Levy has failed them.
Nominations sought for CIOB awards
Celebrating construction excellence in Ireland and Northern Ireland.
EPC consultation in context: NCM, SAP, SBEM and HEM
One week to respond to the consultation on reforms to the Energy Performance of Buildings framework.
CIAT Celebrates 60 years of Architectural Technology
Find out more #CIAT60 social media takeover.
The BPF urges Chancellor for additional BSR resources
To remove barriers and bottlenecks which delay projects.
Flexibility over requirements to boost apprentice numbers
English, maths and minimumun duration requirements reduced for a 10,000 gain.
A long term view on European heating markets
BSRIA HVAC 2032 Study.
Humidity resilience strategies for home design
Frequency of extreme humidity events is increasing.
National Apprenticeship Week 2025
Skills for life : 10-16 February