Tolerance Standards
125 Surface Finish Explained: Ra 125 µin
Jul 11, 20268 min read
A 125 surface finish is Ra 125 µin, the standard as-machined CNC default on US drawings: when to use it, when to go finer, and what it costs.
Tolerance Standards
5 posts
Tolerance Standards
CNC Machining Tolerances: Types and How to Specify
Jul 11, 202615 min read
CNC machining tolerances for buyers: types, ISO 2768, ISO 286 fits, stack-up, process capability, cost impact, and how to specify on drawings.
Tolerance Standards
EN 10204 3.1 and 3.2 Certificates Explained
Jul 9, 202611 min read
EN 10204 3.1 and 3.2 certificates explained: four inspection document types, when to require 3.1 vs 3.2, validation on receipt, and PO wording for material traceability.
Tolerance Standards
What is DIN 7168 and How it Differs from ISO 2768
Jul 9, 20268 min read
DIN 7168 was Germany's general tolerance standard before ISO 2768 replaced it in 1991. Learn how the two standards compare, where tolerance values match, and which to use today.
Tolerance Standards
What Is Surface Roughness? An Overview of Ra, Rz, and Rms Values in Engineering
Jun 23, 202617 min read
Ra, Rz, and Rms measure the same surface but tell different stories. Learn what surface roughness is, how it is measured, and which parameter to specify on your engineering drawing.