Matched context for caster and castor

The page lists matched contexts for caster and castor.

Share - caster	Share - castor	Phrase
15.78%	19.79%	{caster or castor} angle
13.60%	7.10%	{caster or castor} wheel
2.76%	6.31%	adjust {caster or castor} [perform operation]
1.14%	3.70%	wheel {caster or castor}