Technical resources
Published-standard background on tolerances, fits, form, unit weight and material selection for designing and purchasing bars and wire.
Shaft and hole tolerances (ISO 286)
What h and H, IT grades and upper- and lower-case letters mean.
Guide to fits
Clearance, transition and interference fits on an H7 hole basis.
Size tolerance and form tolerance
Why a diameter within tolerance does not guarantee roundness or straightness.
Unit weight table
Theoretical weight per metre (kg/m) of round bar for five materials.
Material selection guide
Machinability against corrosion resistance, leaded against lead-free, low-carbon against stabilized, and lightweight materials.
Purchase specification checklist
What to state in an order and what to check on the mill certificate.
Notes
- This is reference information based on published standards; final specifications are confirmed against the drawing, the applicable standard and the mill certificate.