Slewing ring
Slew ring, turntable bearing, slewing bearing
A large-diameter rolling bearing that lets an excavator's upper structure rotate on its undercarriage while carrying the machine's full weight and the bending moment of a loaded boom.
LEXICON
Lexicon
The words this collection depends on. Machine components most people have never had to name, the materials they are made from, and the market terms that get used loosely. Written to be precise enough to quote.
Machine components
Every object in the collection is named after the part it was. These are those parts.
Track idler
Front idler, guide wheel
The unpowered wheel at the front of a tracked undercarriage that guides the track chain, sets its path and, through the tensioner behind it, holds the chain at working tension.
Drive sprocket
Final drive sprocket, driving wheel
The toothed wheel at the rear of a tracked undercarriage that converts hydraulic motor torque into track movement by engaging the bushings of the track chain.
Track shoe
Track pad, track plate, track link
One plate of a tracked machine's chain: a steel shoe bolted to a link, carrying a grouser bar that bites the ground and spreading the machine's weight over a large enough area to keep it from sinking.
Bucket tooth
Digging tooth, tooth point, bucket tip
A replaceable cast-steel point fitted to the leading edge of an excavator bucket, designed to concentrate breakout force at a small area and to be consumed in service so the bucket itself is not.
Ripper shank
Ripper tine, ripper leg
A heavy curved steel blade mounted behind a dozer or on an excavator arm, used to fracture rock, frozen ground or compacted material that a bucket cannot penetrate directly.
Boom section
Boom, main boom, monoboom
The first and largest arm of an excavator, a fabricated steel box that carries every load from the bucket back to the machine and takes bending, torsion and shock along its whole length.
Hydraulic cylinder
Hydraulic ram, actuator
A sealed steel tube in which pressurised oil drives a piston and rod, converting hydraulic pressure into linear force — the mechanism that moves every arm, blade and bucket on a working machine.
Hydraulic quick coupler
Quick hitch, quick attach
A mechanism between an excavator's arm and its attachment that lets the operator release one tool and pick up another from the cab, without leaving the machine to knock out pins.
Rotary manifold
Centre swivel, hydraulic swivel joint, rotary union
The joint at the centre of an excavator's slew axis that carries hydraulic oil between the rotating upper structure and the fixed undercarriage while the machine turns continuously in either direction.
Track tensioner
Track adjuster, recoil spring, tension cylinder
A grease-filled cylinder working against a heavy coil spring that pushes the front idler forward, keeping the track chain at working tension and absorbing shock when debris jams the track.
Dozer blade
Bulldozer blade, cutting edge, moldboard
The curved steel plate at the front of a bulldozer that cuts and rolls material ahead of the machine, fitted along its base with a bolted, replaceable cutting edge of abrasion-resistant steel.
Demolition grapple
Sorting grab, demolition grab, orange peel grab
A hydraulically operated pair of toothed jaws mounted on an excavator arm, used to grip, sort and load irregular material — demolition rubble, scrap, timber — that a bucket cannot hold.
Digging bucket
Excavator bucket, trenching bucket
The primary excavator attachment: a fabricated steel shell with a reinforced lip, wear strips and replaceable teeth, sized by capacity in cubic metres and by the material it is intended to dig.
Pivot pin
Boom pin, bucket pin, hinge pin
A hardened ground steel shaft that forms the hinge between two structural members of a machine — boom to arm, arm to bucket, cylinder to mount — carrying the entire load through a single axis.
Bogie
Roller frame, track roller assembly, carrier frame
A pivoting frame carrying two or more track rollers, which lets the rollers follow uneven ground independently and spreads the machine's weight along the track rather than concentrating it at fixed points.
Materials and finishes
What the steel and glass actually are, and how each behaves once it is indoors.
Abrasion-resistant plate
Hardox, wear plate, AR plate, Raex, Dillidur, XAR
Quenched and tempered low-alloy steel specified by hardness rather than yield strength — typically 400 to 500 Brinell — used wherever sliding abrasion would destroy ordinary structural steel.
Mill scale
Rolling scale, hot-rolled finish
The blue-grey layer of iron oxides that forms on steel during hot rolling and remains on the surface as it leaves the mill — hard, adherent and frequently mistaken for a deliberate dark finish.
Patina
A surface layer formed on metal by reaction with its environment over time. On steel it is iron oxide, and whether it protects the metal or slowly consumes it depends entirely on which oxide formed.
Weathering steel
Corten, COR-TEN, ASTM A242, A588, EN 10025-5
A low-alloy structural steel with small additions of copper, chromium, nickel and phosphorus that forms a dense, adherent rust layer, slowing further corrosion so the steel can be left unpainted outdoors.
Toughened glass
Tempered glass, safety glass, ESG
Glass heat-treated so its surfaces are held in compression and its core in tension, giving roughly four to five times the bending strength of ordinary float glass and a break pattern of small blunt fragments.
Blackening
Black oxide, cold blackening, gun bluing
A conversion treatment that chemically turns the steel surface itself into black iron oxide, producing an extremely thin, even, dark finish that adds no measurable thickness and almost no corrosion protection on its own.
Design and market
Terms used across collectible design, defined narrowly enough to be useful.
Collectible design
Design art, functional art, collectable design
Furniture and objects produced as unique pieces or in very limited editions, sold through galleries and design fairs rather than retailers, and traded afterwards with reference to maker and provenance.
Pièce unique
One-off, unique piece, one of a kind
An object made once and not repeated. The claim is only meaningful when repetition is actually prevented — either by the maker's undertaking, or by material that cannot be sourced twice.
Provenance
Documentation, certificate of authenticity
The recorded history of an object: what it is, what it was, who made it and when. For work built from salvaged material it is the substance of the claim rather than a formality.
Upcycling
Reusing a material or component in a new application of equal or higher value, without breaking it down to raw material first — the distinction that separates it from recycling.
Brutalism
Béton brut, New Brutalism
An architectural position holding that a structure should show how it stands up, that materials should appear as themselves, and that services should not be hidden behind a decorative skin.