Summary for surface finish chart Discussion
Surface finish chart questions about N9 and N11 are answered by pointing to finishing.com archives letter 7560 for the conversion chart. The original questioner, Christopher Morrison of Machine Works, said he needed to translate Austrian drawing symbols into familiar U.S. surface finish values such as 32 or 63. In the reply, Ted Mooney, P.E., notes that the specification refers to Ra values and gives examples from the chart: N1 equals 0.025 micrometers or 1 Ra, and N2 equals 0.05 mm or 2 Ra. The thread does not spell out N9 and N11 directly in the excerpt, but it indicates that the archive chart is the place to find the conversion. The practical takeaway is to use the referenced finishing.com chart to map the European N-scale symbols to Ra-based standards.
Q. I’m looking for a conversion chart for Machining Symbols. I currently have an Austrian Drawing with the following Machine Symbols Surface finishes: N9 and N11. I need to know what these are in our standards, Like a 32 or 63 Surface Finish. Please let me know if you have any luck.
Thanks,
Christopher Morrison
machine works – Miramichi, New Brunswick, Canada
2003
A. Take a look at finishing.com archives letter
7560 for that chart
This specification refers to Ra values. N1 = .025 micrometers or 1 Ra. N2 = .05 mm or 2 Ra.
AF Kenton
retired business owner – Hatboro, Pennsylvania
2003
A. In order to understand N11, N11 , 32 , 63 Please visit:
www.roymech.co.uk/Useful_Tables/Surface_Texture/Sur_Fin_Values.html
SHINDE UMESH
– Aurangabad, Maharashtra, India
April 6, 2009
Q. Does the surface finish apply to all materials such as teflon or rubber materials or is it strictly for metals? Please advise.
Sandra sargent
– dublin, California, usa
October 3, 2012
A. Hi Sandra. Those surface finishes are about the topography of the surface so they theoretically apply regardless of the material being discussed, but that might be a slightly misleading answer. The standards were designed in response to the issues involved in machining metals and utilizing metals, so they are probably not the best standards by which to describe the finish of materials like teflon and rubber which are manufactured by molding and which are flexible. Please see letters such as 20910, 24465 and 30763 where plastic surface finishing standards are discussed. Good luck.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
October 4, 2012