Tram
Tram turns up in 2 fields: machine shop, textiles. Here is what it means to the people in each one.
Tram in machine shop
To square a mill head or spindle to the table so the spindle axis is truly perpendicular.
Tramming means mounting an indicator on an arm in the spindle and swinging it across the table, front to back and side to side, adjusting the head until readings match on opposite sides of the sweep. A knee mill with a tilting head needs it after any head move; an out-of-tram head leaves a dished or stepped surface when face milling or flycutting.
"Somebody tilted the head for a chamfer and never trammed it back, look at the scallops on this flycut."
Tram in textiles
A loosely twisted silk yarn specifically engineered to be used as the weft in woven fabrics.
This yarn is formed by combining two or more single strands of raw silk with a very low twist, typically around three to six turns per inch. The low twist allows the silk fibers to remain flat and lustrous, maximizing the fabric's sheen and coverage. Weavers use tram exclusively for the filling (weft) in high-quality silks and velvets, contrasting with the highly twisted organzine used for the warp.
"The mill is running organzine in the warp and a three-thread tram in the weft to get that heavy satin finish."