Trade terms
Cladding words, plainly
The words we use on the drawings, the cut lists and on site.
Setting out the pattern
- Development / setting out
- — Unfolding a 3D shape into a flat pattern for cutting.
- Flat pattern
- — The 2D outline that gets cut.
- Cut size
- — The overall flat blank, laps included.
- Stretch-out
- — The flat width of a rolled piece: π × the cladding diameter + the lap.
- Circumference
- — The distance round the cladding, written like "35+" (cm, plus the lap).
- Parallel-line development
- — For shapes with a constant section: straights, lobster-backs, elbows, tees and sets.
- Radial-line development
- — For cones, where every line runs to one apex: in-line reducers and tank cones.
- Triangulation
- — Splitting a surface into triangles using true lengths: square-to-round, flat-side reducers and duct transitions.
- True length
- — The real length of a sloping line, used in triangulation.
- Generator lines
- — The lines drawn along the surface to set out a pattern.
- Template
- — A master pattern kept for repeat work.
- Nesting
- — Fitting the parts onto the sheet with the least waste.
- Cut list
- — The list of pieces with their sizes and quantities.
- DXF
- — The cutting file for the workshop machine (it stays in mm).
Bends, tees and reducers
- Mitre line
- — The angled cut where two pieces meet.
- Segment / gore
- — One piece of a lobster-back bend.
- Half-segment
- — The end piece of a lobster-back — half the angle of the middle ones.
- Centreline radius
- — The bend radius, measured to the centre of the pipe.
- Throat
- — The inside of a bend.
- Heel
- — The outside of a bend (the back).
- Header / main
- — The run a branch comes off.
- Branch
- — The take-off on a tee.
- Saddle cut
- — The curved cut that makes a branch sit on the main.
- Offset
- — How far one end or centre is shifted from the other.
- Set
- — A fitting that steps a run sideways.
- Concentric
- — On the same centre line.
- Eccentric / flat side
- — Centres offset so one side stays level.
- Frustum
- — A cone with the top cut off.
- Apex
- — The point where a cone's lines meet.
Joints, laps and fixings
- Swage
- — A formed step on the end, so one piece slides into the next (male into female).
- Slip swage
- — CladFab's swaged end joint, with a 5 cm overlap.
- Bead
- — A raised rib for stiffness or to locate a joint.
- Lap / overlap
- — Extra metal where two edges join — CladFab's longitudinal lap is 2.5 cm.
- Longitudinal seam
- — The joint running along the length.
- Circumferential joint
- — The joint going round the pipe.
- Watershed lapping
- — Lapping so water runs off, not in: the upper piece over the lower.
- Collar
- — A short upstand that grips the next piece.
- Notch
- — A cut-out for a pipe passing through.
- Band
- — A strap round the cladding.
- Self-tapper
- — A sheet-metal screw.
- Pop rivet
- — A blind rivet.
- Toggle clip
- — The latch on a removable box.
- Pittsburgh / lockform seam
- — A folded seam, mainly on ductwork.
Sizes and materials
- Lagging / insulation
- — The material under the cladding.
- Over the lagging
- — How every size is measured — never the bare pipe.
- Allowance
- — Extra added to the size: CladFab adds 0.3 cm over the lagging.
- Cladding diameter
- — The finished size over the lagging.
- Insulation section
- — For example 76 × 25: pipe 76 mm, insulation 25 mm.
- MTR / MTRS
- — A 1-metre straight casing, or several of them: 1 × MTR, 1/2 MTR, 3 × MTRS.
- Make-up / fill-in
- — A short straight cut to finish a run.
- Pencil rollers
- — Small rolls for small-bore casing (under 8 cm finished).
- Coil
- — The metal strip fed into the MABI.
- Mill finish
- — Plain aluminium.
- Stucco
- — Embossed aluminium finish.
- Gauge / thickness
- — Sheet thickness, for example 0.8 mm.
Ducts, boxes and vessels
- Cheek
- — The flat side panel of a duct bend.
- Wrapper / back
- — The rolled outer panel of a duct bend.
- Turning vane
- — A curved blade inside a square bend.
- Tray
- — The top or bottom panel of duct casing.
- Z-bar
- — A folded trim with three legs.
- Valve box
- — A removable cover over a valve (a square box or a D box).
- Flange box
- — A removable cover over a flanged joint.
- Petal
- — One tapered piece of a domed end.
- Crown cap
- — The small disc on top of a domed end.
- Turned rim
- — The edge folded down on a flat end.