arc - auxi
- armature reaction welding generator
- armco iron
- armco steel
- armor plate
- armor-plate (rolling) mill
- arms of dendrite
- arquerite
- arrangements for synchronizing roll positions
- array of dislocations
- arrest of running crack
- arrest point
- Arrhenius-type equation
- arrow side
- arsenate of cobalt
- arsenate of lead
- arsenate of nickel
- arsenic
- arsenic acid anhydride
- arsenic iron
- arsenic oxide
- arsenic pentachloride
- arsenic skimming
- arsenical antimony
- arsenical cobalt
- arsenical copper
- arsenical ore
- arsenical red silver
- arsenical speiss
- arsenous anhydride
- artefact
- article handling apparatus
- artifact
- artificial abrasives
- artificial aging
- artificial crystal
- artificial pit
- artificially aged condition
- artisan
- as
- as cast