Shop Talk: Machinist Slang, Translated

Thou, skerrick, swarf and the long weight. What we’re actually saying when we talk about your job.

Walk into any Australian machine shop and you’ll hear a language of its own. Here are 217 terms from the floor, translated. Some are useful, some are jokes, and a few are wind-ups every apprentice falls for once.

Find a term

US and UK mark American and British terms. The rest is home-grown. Need the serious numbers instead? See our design guide.

Size and accuracy

How close is close enough, in the words of the people holding the micrometer.

Thou, half a thou: 0.001 in = 0.0254 mm. Old hands still say it in a metric shop.
A tenthUS: 0.0001 in = 0.00254 mm, about 2.5 µm.
A hundredth, a couple of hundredths: 0.01 mm, the metric shop's everyday unit.
A micron: 0.001 mm.
Dead on, bang on, on the money: Exactly on size.
Dead nutsUS: Exactly on size, nothing to adjust.
TLAR: "That looks about right": sized by eye, nothing measured.
Near enough is good enough: Said sarcastically about work that isn't.
Within cooee: Close, but not a measurement anyone would sign.
Fat, heavy: Oversize. "Leave it fat" = leave stock for the finish pass.
Shy, light, under: Undersize. "It's a hundredth shy."
Proud, standing proud: Sticking up above the surrounding face.
A gnat's, a gnat's whisker: A tiny amount.
A frog hairUS: A tiny amount.
A smidge, a skerrick: A little bit, or none at all ("not a skerrick left").
Clearance is clearance: Shop joke: if it goes together, it fits, whatever the gap.
Bump fit, tap fit: Goes in with a light tap from a soft hammer.
Slop, sloppy: Too much clearance; it rattles.
Go / no-go: The two ends of a plug or ring gauge: one must go, one must not.
Witness mark: The faint line left where one cut or surface met another; proof they touched.

Machines and tooling

What the gear on the floor actually gets called.

Bridgy, Bridgeport: Any knee-type turret mill, whoever made it.
The Haas, the Mazak, the Taki: Machines called by maker, not by type.
Slot drillUK: Two-flute end mill that plunges straight down.
Ripper, corncob, hog: Roughing end mill with serrated flutes.
Bull nose: End mill with a corner radius.
Fly cutter: Single-point cutter for facing on a manual mill.
Tip: Carbide insert. "Turn the tip" = index to a fresh edge.
Jobber, stubby: Standard-length drill; short drill.
Gun tap: Spiral-point tap that pushes the chip ahead of it.
Clock, DTI: Dial or test indicator.
Verniers: Any caliper, dial or digital included.
Mic, mike: Micrometer; "mike it" = measure it with one.
Slips, Jo blocksUS: Gauge blocks.
1-2-3 blocks: Hardened blocks 1 x 2 x 3 in, used as parallels and squares.
Wiggler, edge finder: Tool for picking up an edge on a manual mill.
Pull stud: Retention knob on a CAT or BT holder.
Tombstone: Upright fixture block on a horizontal mill.
Dog: Drives work between centres; also a clamp on a fixture table.
Shifter: Adjustable spanner.
Persuader: A hammer.

Setups and workholding

Getting the part held, trued and zeroed before a chip is cut.

Clock it in, clock it up: Run an indicator over the part or vice and true it.
Tram the head: Square a mill head to the table.
Pick up, touch off, zero: Set a work offset or a tool length.
Square it up: Mill all six faces flat and square.
Chuck it up: Hold it in the lathe chuck.
Skim the jaws: Take a light cut on soft jaws so they run true.
Soft jaws: Aluminium or steel jaws cut to suit the part.
Stick-out: How far the tool or part hangs out of its holder.
Skin of its teeth: Barely held; a few millimetres of grip.
First off: First part of a run, checked before the rest are made.
Prove out, dry run, air cut: Run the program slowly or above the part to check it.
Single block: Step through the program one line at a time.
Wind it back: Turn the feed or speed override down.
Feed hold: Stop the axes without killing the spindle.
Babysit: Stand at the machine for the whole cycle because you don't trust it.
Second op, flip it: Turn the part over for the other side.

Cutting and chips

What you hear while the spindle is turning.

Swarf: Chips. Americans just say chips.
Bird's nest: Long stringy swarf wrapped round the part, tool or chuck.
Stringers, tinsel: Long unbroken chips from a chipbreaker that isn't working.
Blue chips: Steel chips coming off hot; fine on carbide, trouble on HSS.
Chatter, singing: Vibration that leaves a wavy finish and a howl.
Rubbing: Edge not biting because the feed is too light; work-hardens stainless.
Dig in: Tool grabs and pulls itself into the cut.
Hog it out: Heavy roughing; take the bulk off fast.
Skim, skim cut: A light pass to clean up.
Spring pass: Repeat the finish pass at the same size to take out tool deflection.
Give it some herbs: Wind up the feed or speed.
Flogging it: Running a tool or machine harder than it's meant for.
Built-up edge: Work metal welded onto the cutting edge; common in aluminium.
Record finish: Visible fine spiral grooves on a turned face.
Suds: Soluble-oil coolant.
Break the edges: Deburr every sharp corner, about 0.2 to 0.5 mm.

Crashes, scrap and fixes

For when the cut didn’t go to plan.

Pranged it: Crashed the machine.
Ate the vice: The program cut into the vice or fixture.
Stuffed, cactus: Broken past fixing.
Expensive swarf: A scrapped part.
One for the bin: A scrapped part, said quietly.
Boat anchor: Scrap, or a machine nobody wants to fix.
Bodgy, dodgy: Poor work or a rough fix.
BodgeUK: A rough fix.
Bush it: Sleeve an oversize hole back to size.
Shim it: Pack it out to make up a gap.
File to fit, paint to match: Joke for hand-fitting a part that was made wrong.
Close enough for government workUS: Joke for work that just passes.

Shop floor and apprentice wind-ups

Smoko, knock-off, and the long weight every apprentice waits for once.

Smoko: Morning or afternoon break.
Knock-off: End of the day.
Leading hand: Senior tradesperson running the floor or a shift.
Fitter and turner, fitter: Mechanical tradesperson; a turner works the lathe.
Boily: Boilermaker: welder-fabricator.
Sparky: Electrician.
Homer, foreigner, government jobUKUS: A private job made on the boss's machines.
Long weight: Apprentice sent to stores for a "long wait".
Sky hook: Apprentice sent for a hook that hangs from nothing.
Left-handed spanner: Apprentice sent for a tool that doesn't exist.
Tin of striped paint, tartan paint: Same joke, paint shop version.
Bucket of steam: Same joke, for the boiler shop.
Board stretcher: Same joke, for parts cut too short.

Sheet metal

Folder, guillo and the rest of the sheet shop.

Folder, brake: Press brake. A pan brake or box-and-pan folder is the manual kind.
Guillo: Guillotine shear.
Top tool, bottom tool: Punch and die.
The V, 8V: Die opening; the rule of thumb is a V about 8 times the sheet thickness.
Gooseneck: Swan-neck punch that clears a return flange.
Fingers: The backgauge stops.
Air bend, bottoming, coining: Bending in the air, pressing to the die, or squeezing past it to set the angle.
Springback, overbend it: The sheet opens up after the punch lifts, so bend past the angle.
Blank, flat, flat pattern: The cut shape before folding. Stretch-out [US] is its length.
K-factor: Where the neutral line sits in the thickness; sets the flat length.
Bend deduction: What comes off the sum of the outside sizes to get the flat.
Return, lip: A short flange folded back from a main one.
Hem: Edge folded flat back on itself.
Joggle: Two close bends that step a flange sideways by about one thickness.
Bump bend: Lots of small bends in a row to make a large radius.
Relief: Small cut at a bend end or corner so it folds without tearing.
Won't clear: The part hits the punch or the machine on a later bend.
Tab and slot: Parts that locate in each other's cut-outs before welding.
Micro-joints, nicks: Tiny uncut bridges that hold laser parts in the sheet.
Nest: Parts laid out on a sheet for cutting.
Kerf: Width of material the cut removes.
Burr side, burr up: The rough side of a punched or sheared edge.
Gauge: Sheet thickness by number; 18 gauge is about 1.2 mm steel.
Oil-canning: A flat panel that pops in and out when pushed.
PEM, clinch nut: Press-in nut for thin sheet.
Rivnut, nutsert: Blind threaded insert set like a pop rivet.
Colorbond, Zincalume: Painted and coated steel sheet.
Checker plate, tread plate: Plate with a raised non-slip pattern.

Welding and fab

From the boily’s side of the shed.

MIG, TIG, stick: Wire-fed, tungsten and rod welding. Stick is MMA.
Gasless: Flux-cored MIG wire that needs no gas bottle.
Rods: Stick electrodes; "low hy" = low-hydrogen rods.
Earth: The work clamp. Americans call it the ground.
Lid, hood: Welding helmet.
Flash, arc eye: Burnt eyes from looking at the arc.
Tack, spot it: Small weld to hold parts in place before welding out.
Weld it out: Run the full welds after tacking.
Stitch weld: Short welds with gaps between.
Fit-up: How well the parts sit together before welding.
Prep: Bevels and lands ground on the edges before welding.
Root, hot pass, fill, cap: The runs of a multi-pass weld, first to last.
Lay a bead: Run a weld.
Puddle, pool: The molten metal under the arc.
Walk the cup: TIG method of rocking the ceramic cup along the joint.
Dip the tungsten: Touch the tungsten into the pool; stop and regrind it.
Sugar, sugared: Crusty oxidised back of a stainless weld done without a back purge.
Back purge: Gas on the back of the joint so the root stays clean.
Heat tint, rainbow: Colours beside a stainless weld; the darker, the hotter it ran.
Pulled, it's moved: Weld shrinkage has distorted the job.
Blew a hole: Burnt through thin material.
Undercut: Groove melted beside the weld and left unfilled.
Pinholes, worm holes: Gas porosity in the weld.
Cold lap: Weld sitting on the plate without fusing into it.
Chip the slag: Knock the flux crust off a stick or flux-core weld.
Stack of dimesUS: Even, rippled TIG bead.
Grinder and paint: Joke: the grinder and paint make a poor welder look good.
Gas axe, oxy: Oxy-acetylene cutting torch.
Hot spanner: Oxy torch used to free a seized nut.
Zip disc, zippy: Thin cut-off wheel for an angle grinder.
Broach: Annular cutter in a mag drill.
RHS, SHS, CHS: Rectangular, square and circular hollow section.
Gal: Galvanised steel.
Dross: Slag stuck to the bottom edge of a plasma or laser cut.

Fitting

Bench work, bearings, and the art of the nip-up.

Bench work: Hand work at the vice: marking out, filing, fitting, assembly.
Mark it out: Scribe the shape and hole centres onto the job.
Pop it: Centre-punch a hole position.
Blue, blue it up: Engineer's blue smeared on to show where two faces touch.
Scrape, flake: Hand-scraping slideways flat, leaving the half-moon pattern.
Lap it: Rub two parts with fine compound until they seat.
Ease it: Take a touch off so it fits.
Draw file: Push a file sideways along the work for a flat, fine finish.
Cook it: Heat a bearing or gear so it drops on the shaft.
Freeze it: Chill a shaft or bush in dry ice or liquid nitrogen so it slides in.
Knock it out, drift it: Drive a pin, bearing or shaft out with a drift.
Puller: Bearing or gear puller.
Run-out: Wobble on a turning part, read on a clock as TIR.
End float: Axial play in a shaft or bearing.
Backlash: Play between gear teeth or in a leadscrew nut.
Seized, frozen: Stuck solid.
Galled: Surfaces welded and torn by rubbing; stainless threads are famous for it.
Nip it up: Tighten lightly.
Gutentight: Tightened by feel; nobody used a torque wrench.
Rattle gun: Impact wrench.
Grub screw: Headless screw. Americans call it a set screw.
Set, set screw: In Australia, a bolt threaded right up to the head.
Cap head, Allen bolt: Socket head cap screw.
Half-moon key: Woodruff key.
Chase the thread: Run a tap or die through to clean up a damaged thread.
Helicoil it: Repair a stripped thread with a coil insert.
Easy-out: Screw extractor for a broken bolt.
Loctite it: Use thread-locker.
Copper grease: Anti-seize compound.

CAD and CAM

From the screen to the G-code.

The drawing, printUS: The dimensioned 2D sheet. Old hands still say blueprint.
The model: The 3D CAD solid.
Dumb solid: Imported STEP or IGES with no feature history to edit.
Fully constrained, it's gone black: Sketch with nothing left free to move; Fusion turns it black.
Blue lines: Under-constrained sketch geometry that can still drift.
Timeline, history tree: The ordered list of features that builds the model.
Roll it back: Drag the timeline back to edit an earlier feature.
Parametric: Sizes driven by named values, so one change updates the lot.
Designer special: A part that can't be made the way it's drawn.
Tolerance everything: Drawing with a tight tolerance on every size, needed or not.
DXF for the laser: Flat-pattern outline sent to the profile cutter.
STEP, STP: Neutral 3D file for swapping models between CAD systems.
Toolpath: The cutter's programmed path.
Adaptive, trochoidal, dynamic: High-speed roughing with constant tool engagement.
Stepover, stepdown: Sideways and depth spacing between passes.
Rest machining: A smaller tool cleaning up what the last one couldn't reach.
Scallop: Ridge left between ball-nose passes.
Air cutting: Toolpath moving through where material has already gone.
Gouge: Toolpath cuts into the finished part.
Sim it, verify: Run the simulation before the machine.
Post it: Run the post processor to turn the toolpath into G-code.
The code, the program: The G-code. Old timers still say the tape.
Hand code: G-code typed by hand, no CAM.
Conversational: Programming at the control with its own menus.
Canned cycle: One-line drilling, tapping or boring cycle such as G81 or G83.
Drip feed, DNC: Feeding a program too big for the control's memory over a cable.
Comp, cutter comp: G41 or G42 so the control offsets for tool radius.
Rapid into it: G0 move straight into the part or vice: a crash.
Work offset, G54: Where the part zero sits on the machine.

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Shop Talk: Machinist Slang, Translated

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