Start here: four machines that handle steel
Two of these four are fiber lasers. Two are dot peen machines that press the mark in with a hard pin. Pin machines come in two kinds, electric and pneumatic, and that choice decides how deep the mark goes.
STEEL · DIRECT PART MARKING Get Free Steel Marking Solutions
Steel Marking Machine for Parts That Face Zinc, Heat and Grit
Structural steel, pipe, valves, heavy equipment. Steel is the easiest metal to mark, and the hardest to keep marked. Beams go into molten zinc. Shafts go into a furnace. Castings go through a blast cabinet.
So the real question is not how to mark steel. It is what happens to the part next. HeatSign supplies fiber lasers for finished parts. For everything else, HeatSign supplies dot peen machines that press a mark deep enough to read through zinc, scale and paint.
Reply within one working day. Free marking test. No sample shipping needed. Working in stainless? See stainless steel marking.
10+ years
Industrial marking only
40+
Countries served
1 year
Warranty, CE and RoHS
Free
Marking test before you buy
HS-FL Desktop Fiber Laser Marking Machine
20W – 60W bench system
Pick this for finished parts in batches
- Machined parts, nameplates, tags
- Fast, and nothing touches the part
- Works on steel of any hardness
- USD 2,500 – 7,000
HS-PFL Portable Fiber Laser Marking Machine
20W / 30W / 50W handheld
Pick this when the part cannot move
- Frames, tanks, installed steelwork
- Marking head weighs only 1.4 kg
- Industrial touchscreen, no computer
- USD 1,950 – 3,800
HS-DE Electric Dot Peen Marking Machine
Electric drive, 0.1 – 0.5 mm deep
Pick this when no zinc bath follows
- Shafts, gears, valve bodies, nameplates
- Quiet, and no compressor to buy
- Depth falls as the steel gets harder
- USD 1,300 – 2,900
HS-PC Pneumatic Dot Peen Marking Machine
Air driven, deeper on the same steel
Pick this when zinc, paint or grit follows
- Beams, sections, castings, pipe
- Magnetic base holds it on the steel
- Holds its depth on hard steel too
- USD 1,500 – 2,800
Dot peen: which drive
Electric
Pneumatic
Which driveDepth on steel
Electric0.1 to 0.5 mm. The harder the steel, the shallower it gets.
PneumaticDeeper on the same part, and it holds that depth on hard steel.
Which driveStriking force
ElectricAbout 5 to 8 N.
PneumaticAbout 10 to 15 N at 4 to 6 bar.
Which driveWhat the shop needs
ElectricA power socket. Quiet enough for a shared room.
PneumaticShop air at 4 to 6 bar. Noticeably louder.
Steel engraving machine or dot peen: watch both run
A photo shows you what the mark looks like. A video shows you how long it takes, and how deep it goes. On the left, a HeatSign fiber laser marking steel in about two seconds. On the right, a dot peen machine pressing the same mark in.
Fiber Laser Marking
Nothing touches the part. It marks a part in a few seconds, and the surface stays flat. This is the one to buy if your parts are finished and you mark them in batches.
Dot peen marking
A hard pin hammers the mark into the metal. Slower, and loud enough that you will hear it across the shop. But you can feel the dots with a fingernail, and that is what still reads after zinc, a furnace or a blast cabinet.
Which steel marking machine fits your part
Find your part in the first column and read across. The second column decides the answer. If zinc, heat, grit or paint is still ahead, a surface mark will not be there at the end.
Your steel part
What happens next
HeatSign marking machine
Depth needed
Your steel partMachined partsTurned, milled, bright finish
What happens nextNothing. The part ships as it is.
HeatSign marking machineHS-FL desktop fiber laserFine detail, no contact, no depth needed. Flat stock? See steel plate marking.
Depth neededSurface
Your steel partHardened partsAlready quenched, over 62 HRC
What happens nextFinal inspection, then it ships.
Depth neededSurface
Your steel partShafts and gearsMarked before hardening
What happens nextQuench and temper. Scale forms.
Depth needed0.3 mm
Your steel partBeams and sectionsFabricated steelwork
What happens nextA zinc bath at about 450 °C.
HeatSign marking machineHS-PC pneumatic dot peenMagnetic base, so nobody holds it. Whole shop to set up? See steel fabrication marking.
Depth needed0.5 – 0.8 mm
Your steel partCastings and forgingsScale, rust, casting texture
What happens nextShot blasting, then machining.
Depth needed0.5 mm and up
Your steel partPipe and valve bodiesRound, and often coated later
What happens nextCoating, then years in the field.
Depth needed0.3 – 0.6 mm
Four steel marking problems and what fixes each one
These are the failures HeatSign is asked about most. Each answer also names the case where our machine is the wrong buy.
Zinc buries a shallow mark
Hot-dip galvanising drops the part into molten zinc at around 450 °C. The coat that comes out is 80 to 100 microns thick, sometimes more. A laser mark lives on the surface, so the zinc simply covers it.
Even a pressed mark can vanish if it is too shallow. That is why an electric unit at 0.3 mm is not enough here. Go to 0.5 mm or deeper with air, and the dots still read on the finished beam.
Zinc after marking: a laser is the wrong tool.
A furnace hides a laser mark
When steel is hardened in a furnace, a dark, flaky skin grows over the whole part. Workshops call it scale. A laser mark only changes the colour of the surface. The scale grows right over it, and the mark is gone.
There are two ways round this. Press the mark into the metal with a pin before the part goes into the furnace. Or wait until the part comes out, clean it, and then mark it with a laser. The one thing that does not work is laser marking first and heating after.
Furnace still to come: press the mark in with a pin first.
Nobody can hold 5 kg all shift
A pneumatic head is heavy. Ask an operator to hold one against a beam for eight hours. You get crooked marks, sore wrists, and a machine nobody wants to use.
A magnetic base solves it. Put the unit on the steel, flip the switch, and the magnet carries the weight. The marks come out straight because nothing is shaking.
Big steel: ask for the magnetic base.
A pin will not bite hardened steel
Past about 62 HRC the steel is as hard as the pin. On a 60 HRC face a carbide tip leaves 0.01 to 0.05 mm. That is a scratch, not a readable mark. Pin wear climbs at the same time.
A laser does not care how hard the metal is. On parts that are already hardened, a laser is the answer and our dot peen range is the wrong buy.
Already hardened: use a fiber laser.
Three steel jobs and what changed
Real HeatSign installations, with the numbers the customers measured. Names are withheld at their request.
Hardened engine parts, marked before the test bench
Laser marks were fading under heat and mechanical stress. The plant moved to an electric dot peen station in pre-assembly. Depth is around 0.3 mm, a few seconds per part, three shifts a day.
100%of data matrix codes still scanned after engine testing
32%less rework, because every mark read first time
7 monthsto pay back the machine
Heavy castings, marked where they stand
Large castings could not be moved to a marking station, so the numbers were hammered in by hand. A handheld electric unit at 0.3 mm replaced that at final inspection, on rough cast iron and alloy steel parts.
45%faster than hand stamping
98%operator satisfaction, even on uneven faces
20%lower labour cost per batch
Automotive parts, off etching and onto a laser
An etching process was slow and the marks faded. The plant wanted a permanent mark that never touches the metal, and that fits inside an automated line. They took an HS-FL30 fiber system.
5×faster marking than the old process
Passon wear, heat and chemical resistance
ISOand automotive marking standards met
Will the mark pass your audit
Most steel marking is done because a standard says so. Here is what four common ones ask for, in plain terms, and the HeatSign machine that meets each one.
ISO 4030 · 49 CFR 565
Vehicle VIN
Seventeen characters, no letters I, O or Q, plus a check digit in position nine. It has to be clear and impossible to remove quietly.
7 mm characters, about 0.2 mm deep
API SPEC 5L
Line pipe
The pipe number, heat number, steel grade and test data go on the outside surface. Cold rolling or low stress dot marking is the named method.
About 50 mm in from each pipe end
EN 1090
Structural steelwork
CE marking needs an unbroken trail from mill to finished frame. The heat number is the physical link, and it has to reach site intact.
Deep enough to read after galvanising
MIL-STD-130 · AS9132
Defence and aerospace
Machine readable identity means steel DPM engraving of a Data Matrix ECC 200 code. A graded read then proves it scans. Dot peen and laser are both named methods.
Graded to ISO 15415 or AIM DPM
High-contrast laser marking on steel, and where a small machine stops
Steel takes a laser mark more easily than almost any metal. That is why a cheap machine looks tempting here. Below is what it can do, and what it cannot.
Black marks and shiny marks, from one laser
A laser can make two kinds of mark on steel. At low power, moving slowly, it heats the surface until it turns dark grey or black. Nothing is cut away. At high power it burns a shallow groove into the steel, and the groove looks light and shiny.
Use the black mark for anything a scanner has to read, like data matrix codes and part numbers. Use the shiny mark for words people read from a distance. Both are permanent laser marking on steel. The mark is part of the metal itself, so it cannot peel or rub off like paint or a label.
One limit. Neither mark survives galvanising, shot blasting or a furnace. Only choose between black and shiny if the part is already finished. For the deepest marks, see deep dot peen marking.
Laser engraving steel: what a hobby machine cannot do
A small hobby laser can mark steel. The steel is not the problem. The machine is. A hobby laser is made to run a few hours at a time. A factory needs one that runs all day, every day, for years.
Depth is the second problem. For a mark you can feel with your finger, a laser has to pass over the same spot many times. A dot peen pin does it in one go.
Every HeatSign machine on this page is built to run all day in a factory. A cheap machine that breaks down, or wears out in a year, ends up costing more for every part you mark.
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Steel marking machine FAQ: seven questions from the shop floor
Seven answers you will not find above. All of them come up in real HeatSign quotations.
Do we need to clean the steel before marking?
It depends on the machine.
A dot peen machine does not need clean steel. The pin pushes through rust, oil, old paint, and the dark skin that steel has when it leaves the mill. You can mark parts straight from the saw or the casting line.
A laser needs a cleaner surface. Oil burns and gives off smoke, and a dirty surface gives a different result on every part. Wipe the part with a cleaning solvent first. If the steel has a thick, flaky layer on it, remove that before marking.
Does someone have to hold the machine all shift?
No. Most jobs need no holding at all.
With a bench machine, the part goes to the machine. Nobody holds anything.
The handheld laser head weighs under 1.5 kg. That is light enough to hold for short jobs. For long runs, ask us about a stand so it does not have to be held.
The handheld dot peen machine is heavier, about 5 kg. On steel, a magnetic base holds it in place for you. Put it on the part, turn the switch, and let go. The magnet carries the weight, so every mark comes out straight.
On round or uneven parts, where a magnet cannot sit flat, a clamp does the same job. Tell us the shape of the part and we will suggest one.
Can a pressed mark weaken the part?
Very little, if you put it in the right place. A dot peen pin makes many light taps. A hand stamp makes one hard blow. Light taps put far less stress into the metal.
Mark a flat area, away from corners, grooves and any part that bends in use. If the drawing does not allow pressed marks, use a laser instead.
How hard is too hard for a pin?
About 62 HRC is where a pin stops working. Up to 55 HRC a carbide tip marks normally. Between 55 and 62 it still marks, but the dots get shallow and the pin wears out far faster.
Past 62 the tip is no harder than the part. On a 60 HRC face you get 0.01 to 0.05 mm, which reads as a scratch. Mark those parts with a laser, or press the mark in with a pin before they are hardened.
Do we have to type in every serial number?
Set the first serial number, for example 1001. The machine adds one for each new part: 1001, 1002, 1003, and so on. It can also add today’s date or the shift number to every mark on its own.
Already have a list of numbers? Load it from an Excel file, or scan the barcode on your work order. The machine marks them in order, one per part. No typing means no typing mistakes.
Apart from the machine, what else will we pay for?
Very little. Here is the full list.
Fiber laser: it uses no ink, no labels and no other supplies. If you mark oily or coated steel, add a fume extractor to clear the smoke.
Electric dot peen: only the pin wears down. A new pin is cheap and takes a few minutes to fit.
Pneumatic dot peen: pins, plus compressed air. If your shop has no air line, you will also need a compressor.
The marking software comes with every machine. There is no licence to pay for each year.
Will the marked spot rust before the rest of the part?
It can, on plain steel with nothing on it. A laser mark leaves the surface a little rough, so water stays there longer than on the smooth metal around it. If parts are stored somewhere damp, the mark may show rust first.
Usually this does not matter, because the part gets painted, oiled or coated later. If it stays bare and sits outdoors, choose a dot peen mark. A pressed dent stays readable even when the surface rusts.