ISO 14521:2026

This document specifies formulae for calculating the load capacity of cylindrical worm gears and covers load ratings associated with wear, pitting, worm deflection, tooth breakage and temperature. Scuffing and other failure modes are not covered by this document.

NOTE 1 The load rating and design procedures are only valid for tooth surface sliding velocities, , less than or equal to 25m/s and contact ratios greater than 2,1.

NOTE 2 For wear, load rating and design procedures are only valid for tooth surface sliding velocities which are above 0,1m/s.

NOTE 3 The rules and recommendations for the dimensioning, lubricants or materials selected by this document only apply to centre distances of 50mm and larger. For centre distances below 50mm, method A applies.