ASME / ISO Chart References
Interactive IT grade tolerance tables, surface finish Ra charts, fit selection diagrams, and GD&T symbol reference guide based on ASME and ISO engineering standards.
ASME / ISO Chart References – Standards Made Interactive
Interactive versions of the most-used ASME and ISO reference charts: tolerance grades, surface finish, fit selection, and GD&T symbols — all with dynamic filtering and comparison.
Why Interactive Standards Charts?
Engineering standards handbooks contain hundreds of pages of tables. Finding the right IT grade for a 50 mm shaft, or the correct surface finish code for a ground surface, requires flipping through tables. Interactive charts let you filter, highlight, and compare instantly — reducing lookup time and errors. These tools visualise the standards data that underpins the Engineering Drawing/Tolerancing calculators.
Charts Available:
- 📊 Tolerance Grade Chart – ISO 286 IT grade values (IT1–IT16) for standard size ranges, filterable by diameter and grade.
- 🔬 Surface Finish Reference – Ra/Rz/N-grade table with achievable range per process; sortable and filterable.
- 🎯 Fit Selection Chart – Visual clearance/transition/interference fit regions for common ISO fit combinations.
- ⊙ GD&T Symbol Reference – Complete GD&T characteristic symbols with definitions, tolerance zone descriptions, and application examples.
ASME / ISO Chart References
ISO tolerance grades, surface finish standards, H7 fit selection, and GD&T characteristic reference.
ISO Tolerance Grade Chart (IT1–IT16)
Compute ISO 286-1 IT tolerance values (μm) for any size range and IT grade. Formula: i = 0.45·D^(1/3) + 0.001·D, IT value = factor × i. (D = geometric mean of size range, in mm.)
D_mean = 23.2379 mm | i = 1.3074 μm
IT Grades to Chart: