Terms starting with J

The outer plastic sheath of a fiber cable, chosen for fire rating indoors and for UV and moisture resistance outdoors.

The shaft and linkage system that lets one motor move a burner's fuel valve and air damper together.

A thin nut, roughly half to two-thirds standard height, run up against another nut or part to stop it turning.

Pipeline slang for the high-voltage holiday detector, and also for the coating flaws it finds. Shop talk

Lightweight pull string blown or vacuumed through empty conduit, then used to pull in heavier rope or wire. Shop talk

Lines running in the machine direction of a spunlace fabric, caused by blocked or damaged water jets. Shop talk

Clipped jobsite form of journeyman, as in ask your jman before you touch that panel. Shop talk

Job mix formula: the approved recipe of gradation and binder content a plant must produce on a project.

Shop name for gauge blocks: lapped steel or ceramic blocks, accurate to millionths, stacked to make any length. Shop talk

Shop name for gauge blocks, precision steel or ceramic blocks wrung together to build reference lengths. Shop talk

The gap between mating parts in a brazed or soldered joint, which controls capillary flow and strength.

The density measured at a longitudinal joint, often specified separately because joints compact poorly.

Setting the screed so the new mat overlaps the old edge slightly and sits just high enough to roll down flush. Shop talk

End-quench test that measures a steel's hardenability by spraying water on one end of a hot bar.

Licensed electrician who has finished an apprenticeship and passed an exam, qualified to work unsupervised.

Shop name for the full-width parent roll wound at the paper machine reel before slitting. Shop talk

A short fiber cable with connectors on both ends, used to patch equipment to panels or panels to each other.

A worker who makes brief entries into very high radiation spaces, absorbing a large dose allowance in minutes. Shop talk

An overlap between a new survey and an adjoining or older survey, compared to check consistency.

The temperature of the active semiconductor region inside an LED, which governs its output, color and lifetime.