عنصر أنبوبي صلب يناسب بين المحمل وغطاءه، تم تصميمه في المقام الأول كسطح تآكل قابل للاستبدال داخل الجدار الداخلي للغطاء.
steel,mil-s-5626; cadmium plated,p.s. 13101,type 2,class 2,mcdonnell douglas corp; 0.6300 in. min and 0.6500 in. max lg; 2.4010 in. min and 2.4110 in. max id; 2.5820 in. min and 2.5830 in. max od; internal flange at one end; 0.0820 in. min and 0.1020 in. max thk; 2.1900 in. min and 2.2100 in. max id; heat treat to rc 32-37 general characteristics item description, "76301-ps 21201,cl b specification (includes engineering type bulletins, brochures,etc., that reflect specification type data in specification format; excludes commercial catalogs, industry directories, and similar trade publications, reflecting general type data on certain environmental and performance requirements and test conditions that are shown as "typical", "average", "nominal", etc.)." test data document