RH

RH stands for right hand, and in manufacturing it denotes orientation from the operator's perspective when facing a machine or work station. This matters because equipment is often handed, meaning its geometry, controls, or feed direction differs depending on which side you approach from. A lathe spindle, a press brake, or a conveyor system designated RH will have its functional features mirrored compared to its LH (left hand) equivalent.

The convention originated in tool design and machining, where cutting tools, dies, and fixtures need explicit chirality. A right-hand drill bit has flutes that spiral in one direction; a left-hand version spirals the opposite way. Similarly, an RH spiral classifier in mineral processing discharges material to the right when viewed from above, while an LH model does the opposite. Specifying RH or LH removes ambiguity in purchase orders and assembly drawings.

In practice, RH notation appears on sales drawings, bill of materials entries, and equipment nameplates. A hydraulic cylinder, a screw conveyor, or a rotary valve must be ordered with the correct hand designation or it will not fit the production line as designed. Changing from RH to LH mid-production or retrofitting the wrong hand can require expensive rework, duplicate inventory, or line reconfiguration.

The term is most common in discrete manufacturing, where custom or semi-custom equipment is the norm. High-volume consumer goods plants and fully automated assembly lines may use RH and LH less often because their layouts are purpose-built and standardized. However, any shop floor with modular presses, customized tooling, or flexible manufacturing cells will encounter RH specifications regularly in their technical files and supplier communications.