Machinist’s Reference Tools
Three static reference pages — hole size, hardness and starting surface speed. No login, no script: the numbers are on the page, and every one of them carries the standard or vendor document it was read from.
The three tools
Hole size, hardness and speed are one chain of decisions: the drawing gives the material and the thread, the material picks the speed window, the hardness tells you which material group you are really in. Each page below owns its numbers and its sources.
Tap Drill Size Chart
Metric and imperial tap drill sizes by thread and target thread engagement, with the tolerance class each row is calculated for.
ExploreHardness Conversion Chart
HRC, HBW and HV equivalents for carbon, alloy and tool steels, with the standard each published table comes from and where the conversions stop being valid.
ExploreCutting Speed Calculator
Recommended surface speeds by material group and operation, each row carrying its vendor document, plus the rpm arithmetic worked through on the page.
ExploreWhere to go next
Applications by Material
Once the speed number is settled, the application pages give the tool-family decision for the material itself — steel turning, aluminum milling, hardened steel and stainless.
ExploreCutting Tool Catalog
The tool families the charts point at, listed by category with grades, geometries and the specifications each category page carries.
Explore