جسم أسطواني ذو بنية صلبة أو مجوفة يوفر العناصر الدوارة في المحمل الأسطواني.
mil-g-23827 mil spec single material response lubrication material document and classification, astm b194 assn std 1st material response or astm b197 assn std 1st material response or astm b196 assn std all material responses overall material document and classification, 3.4955 inches minimum and 3.4960 inches maximum rolling element diameter, copper alloy 172 or copper alloy 173 overall material