Tool Steel Technical Support and Heat Treatment Guidance

Tool steel technical support is worth having only if what it hands you before the order is still readable years after the steel shipped. A grade mapping, a delivered condition, a hardening route: three things that go out in writing at the enquiry stage, get forwarded down to the shop that will actually run the furnace, and come back out of the file the day somebody has to work out where a tool went wrong.

Fucheng runs a six-person technical desk inside a works that melts, electroslag remelts, forges, anneals, finishes and inspects every bar it sells. The people who write our annealing schedules are in the same building as the furnaces those schedules run on.

Send the grade and the section

Send the grade, the section and the finished tool behind it, and a written answer reaches you inside 24 hours on a working day.

If you would rather read something first, ask for a recent EN 10204 3.1 MTC and check the delivered hardness on it.

Send the grade and the section Ask the technical desk
  • Sixteen metallurgy and process engineers issuing the schedules
  • Furnace uniformity held to ±5 °C and controlled cooling at 20 °C per hour or slower
  • 100% ultrasonic testing to SEP 1921 Class D/d or E/e
  • An EN 10204 3.1 MTC against every heat
  • Routes and records kept ten years

Tool Steel Technical Support Scope

Six things come off this desk, and all six arrive in writing.

Tool steel technical support desk with a grade file open on the bench
The deskSix people inside a commercial and technical group of eighteen, engaged at the enquiry stage rather than after the order is placed.
  • 01 · GradeGrade mapping across AISI, DIN and W-Nr, JIS, GB, ASSAB and BÖHLER designations onto one of our fourteen grades.
  • 02 · ConditionDelivered condition, stated as annealed or pre-hardened with the hardness window that belongs to it.
  • 03 · RouteA numbered heat treatment route for the grade and the section you are buying.
  • 04 · SurfaceSurface condition and the allowance left for the operations that follow ours.
  • 05 · Extra testsThe extra tests available on that grade and how to specify them on the order.
  • 06 · Mixed listAnd for a mixed list, an answer written line by line rather than one date for the whole sheet.

Annealed Delivery and the Hardening Furnace

Our heat treatment area runs two lines with two different jobs.

The annealing region
Holds eight bogie hearth furnaces, each with a 6,000 by 2,000 by 1,500 mm chamber taking a 30 tonne charge on a cycle of about three days.
Beside it
Sits one quench and temper line with two pit furnaces, 4,000 mm deep by 1,600 mm in diameter.
Twenty-six people
Work these lines, to schedules issued grade by grade by the metallurgy and process engineers.
Bogie hearth furnace charge of annealed tool steel bar being drawn out
Annealing regionEight bogie hearth furnaces, a 30 tonne charge on a cycle of about three days, in a chamber held to ±5 °C.

Almost everything we ship leaves the first line. Annealed delivery means the number we put our name to is the annealed hardness of that heat, measured on it and written onto its EN 10204 3.1 MTC, sitting inside the window published for the grade. Where a reading falls outside, that heat goes back through the annealing cycle and is measured again before anything ships, which is what makes the figure on the certificate a window that was held rather than a range that was reported.

That reading is one of the eight inspection steps every heat goes through, and the certificate carrying it is signed once all eight are complete. It is also the condition your customer machines in. Every cut, every milled pocket and every drilled hole in a die goes into the steel at this hardness, days or weeks before a furnace is switched on, which is why a window held tightly is worth more to a die shop than a low headline figure.

A grade that arrives soft enough to cut and consistent enough to programme once is a grade that keeps its machining estimates honest.
Brinell hardness tester reading annealed tool steel delivered condition
Measured on the heatThe annealed hardness written onto the certificate is the reading taken on that heat, not a figure copied off a datasheet.
Pit furnace quench and temper line for pre-hardened mould steel plate
Quench and temper lineTwo pit furnaces, 4,000 mm deep by 1,600 mm in diameter — the only line whose hardness reaches your customer as delivered.

Annealing Schedule and Delivered Hardness Windows

Every annealed heat is cooled after soaking at 20 °C per hour or slower to below 600 °C before the charge leaves the furnace, in a chamber held to ±5 °C. Structure comes from refining. These are the windows a heat has to land in.

Delivered Hardness Windows

GradesDelivered condition
H13, H11, H10, 1.2367Annealed, 235 HB max
1.2714Annealed, 250 HB max
D2, D3, D6, DC53Annealed, 255 HB max
O1Annealed, 220 HB max
1.2316, 420Annealed, 245 HB max
M2Annealed, 269 HB max
1.2085Pre-hardened, 29 to 33 HRC
420Pre-hardened, 30 to 34 HRC
Annealed tool steel bar ends held inside the delivered hardness window
Held, not reportedA reading outside the window sends that heat back through the annealing cycle, and it is measured again before anything ships. That is the difference between a window that was held and a range that was reported.
Brinell impression measured on an annealed tool steel test face
On the heat itselfThe figure that reaches the certificate is the reading taken on that heat, in a chamber held to ±5 °C.

Heat Treatment Routes in Writing

A route is issued by the same sixteen metallurgy and process engineers who write the annealing schedules our own furnaces run, and it goes out through the technical desk.

It carries a document number and a date, it is filed with the records for that order for ten years, and it is written in a form you can forward without editing, to your customer or to the heat treatment shop he subcontracts.

Metallurgy and process engineer writing a numbered heat treatment route
Same hands, same buildingThe engineers who set our own annealing schedules are the ones who write the route that leaves the desk.
Heat treatment route Document no. Date of issue

What it sets out is the sequence for that grade at the section you are buying.

  1. Stage 01PreheatThe preheat stage.
  2. Stage 02AustenitisingThe austenitising step.
  3. Stage 03QuenchThe quench.
  4. Stage 04TemperingIncluding whether the grade takes a second temper and what that second temper is there to do.

It also states the condition the steel will arrive in, because a route only means something against a starting point, and the two belong on one sheet rather than in two emails.

Figures belong with the grade, so they live on the grade pages rather than here. H13, 1.2367, H11, D2, DC53, D3, D6 and O1 each carry their own.

The number on the document earns its keep later. A route issued against one order can be quoted back on the repeat two years afterwards, so the question of what was run the first time has an answer that does not depend on anyone’s memory, and a shop that changes hands or changes staff can pick up the same sheet. Where the grade or the section changes, a new route is issued and numbered rather than the old one being amended.

Routes reach you inside 24 hours on a working day, on the same clock as every other technical question, before the order and after it.
Numbered and dated heat treatment route filed with the order records
Filed by numberQuoted back on the repeat two years afterwards.
Furnace control panel at the far end of the tool steel heat treatment chain
The far endThe cycle is run by the shop that owns the furnace.

Grade Equivalents and Written Comparisons

Enquiries rarely arrive in our designations.

They come as a Japanese grade, a European material number, a Chinese standard or a European mill’s brand name, copied off a drawing that has been through several hands.

The desk maps the designation onto one of our fourteen grades and confirms it in writing, in a form that can go straight back down to whoever wrote the drawing. Where a designation sits outside the fourteen, what comes back is a written comparison instead.

Customer drawing designation being mapped by tool steel technical support
Through several handsA designation lifted off a drawing, mapped onto one of fourteen grades and confirmed in writing.
  • Closest

    Which of our grades is closest

    Named outright, against the designation on the drawing.

  • Difference

    Where the composition windows differ

    Element by element, as measured on our heats.

  • Consequence

    What that difference means for the tool

    Read against the tool described in the enquiry, not in general.

The grade on the order stays your decision, made against a document rather than a substitution nobody flagged.

How an enquiry is taken in, and what is checked before it is accepted, is set out on the about page.

Optical emission spectrometer reading composition on a tool steel heat
Composition windowsMeasured on every heat.

Delivered Surface and Machining Allowance

Four surface conditions are available across the range. The choice decides what the furnace at the far end is presented with.

Turned, ground and six face milled bar has had its decarburised skin taken off here, inside the 3 to 6 mm per side allowance carried on black forged material by section. Black forged and descaled bar arrives with that layer still on it, and with the allowance to remove it.

Which features leave at final size and which carry allowance for the operations after us is written into the order confirmation feature by feature, so the sheet that goes to the machine shop and the sheet that goes to the heat treater say the same thing.

  • Black forgedAnd descaled — the decarburised layer still on it, with the allowance to remove it
  • TurnedSkin taken off here
  • GroundSkin taken off here
  • Six face milledSkin taken off here
Turned tool steel bar with the decarburised skin removed at the works
TurnedThe decarburised skin taken off inside the allowance carried on black forged material.
Six face milled tool steel block left with machining allowance
Six face milledWhich features leave at final size is written into the order confirmation feature by feature.
Cut to length
±2 mm, adding two days, on the saw cutting line.
Ground and milled
Ground thickness to ±0.05 mm and milled flatness to 0.1 mm per metre, adding five days, on the grinding and milling machines.
To your drawing
Quoted per drawing.

Two Deliveries of One Grade

Certificates that scatter tell him to re-establish it, and the cost of finding that out on a production die is the reason the check is worth making on paper first.
Tool steel bar from two deliveries of one grade stacked in a rack
Retrievable by numberBoth heats stay retrievable for ten years, with the melting date alongside.

Both heats stay retrievable by number for ten years, and records pulled that way come out with the melting date of the heat alongside them, so a certificate can be placed against the order it belonged to. Where two certificates do not read the way you expected, send us the two heat numbers and the underlying records come out of the file for both.

The moment this check is worth the twenty minutes it takes is the point where a grade moves off a trial and onto a regular replenishment rhythm, because that is the point where your customers start writing a fixed cycle around what you supply.

Heat Treatment Records at Your End

  1. 01The first is the piece against the heat number. Every piece ships with a heat number tag, and cut lengths are marked individually, so the link survives the day a mixed delivery is split across a rack.
  2. 02The second is the cycle that was actually run: the temperatures used, the soak, the quench, the tempering. Not the route we recommended, but what the furnace did on the day.
  3. 03The third is the hardness measured after hardening, on the tool or on an offcut from the same piece.
Heat number tag wired to a tool steel bar for record keeping
Piece against heat numberCut lengths marked individually, so the link survives a split delivery.
Hardness measured after hardening on an offcut from the same piece
After hardeningOn the tool, or on an offcut from the same piece.

Extra Tests Specified on the Order

Eight inspection steps run on everything we ship.

Beyond them, four tests are available on request and are specified on the order rather than assumed.

  1. Non-metallic inclusion rating, by ASTM E45, DIN 50602 or ISO 4967, reported as measured.
  2. Charpy V-notch impact testing, with specimen orientation set by you.
  3. A hardening coupon on annealed grades, run to your customer’s own cycle.
  4. An unpolished 420 coupon from the same heat, for your customer to polish.
Metallographic microscope rating non-metallic inclusions on a heat
Assessed by the method you nameASTM E45, DIN 50602 or ISO 4967, and reported as measured.
Each is named on the order and reported on the certificate covering that heat.
Charpy V-notch impact test machine used for extra tests on the order
Orientation set by youSpecimen orientation is nominated on the order, not chosen here.
Ultrasonic testing of tool steel bar to SEP 1921 class D/d or E/e
Bar by bar100% of the material, at the class your order names.

Measured Ratings and Acceptance Levels

Grain size and carbide distribution
Rated on every heat, and the measured rating is written onto that heat’s certificate.
Ultrasonic testing
Covers 100% of the material, bar by bar, to SEP 1921, tested and reported at whichever class your order names, Class D/d or Class E/e.

What that gives a buyer is a set of figures attached to a heat number, produced on the material in the crate and retrievable ten years later. A rating your customer’s laboratory can reproduce on the same piece, against a method named on the same document, is what a quality department is asking for when it asks for evidence.

Where the metallurgy behind those ratings comes from is covered on electroslag remelting and fine grain refinement.

Technical Desk and Response Time

The technical desk is six people inside a commercial and technical group of eighteen, and it comes in at the enquiry stage rather than after the order is placed, because most of what it settles has to be settled before a bar is cut.

Technical questions are answered within 24 hours on a working day, before the order and after it, at the same standard. A document list from your quality department is answered item by item against that list.

  • Twenty-sixPeople in heat treatment behind the desk
  • SixteenMetallurgy and process engineers writing the grade schedules
  • Thirty-fourIn quality and inspection, of whom the ultrasonic operators are trained and examined to ISO 9712 Level II and re-certified every three years
  • One signatureRelease is signed by the quality department alone

One routing rule saves the most time: a question that carries a heat number goes straight to the people holding the records for that heat, rather than up and down a chain.

Tool steel technical support desk answering within 24 hours
Same clockBefore the order and after it, at the same standard.
Heat records and route documents archived for ten years
Held ten yearsA question carrying a heat number lands with the people who hold that file.

Tool Steel Technical Support for Distributors

We supply the distribution layer.

Tool rooms and die shops that reach us directly are pointed back to the distributor in their market, and quotations are issued to distributors.

That shapes how this desk writes. Every answer that leaves it is drafted to be forwarded.

Written answer drafted to be forwarded to a distributor's customer
Under your own coverThe technical question gets answered properly, and the customer who asked it stays yours.
  • The grade confirmation
  • The route document
  • The delivered condition
  • The allowance note
You pass it down under your own cover, the technical question gets answered properly, and the customer who asked it stays yours.

It also means a distributor carrying fourteen grades does not need a metallurgist on staff to carry them. A first order can be run as a trial and moved onto a regular replenishment rhythm once your customers have confirmed the material, with the same desk answering throughout.

How a replenishment account runs day to day is on the distributor program page.

Fourteen grades of tool steel carried on a distributor's rack
Fourteen gradesCarried without a metallurgist on staff.

Tool Steel Technical Support Before the Order

  • The grade confirmation
  • The window
  • The numbered route
  • The certificate from a recent heat

Every document named on this page exists before you commit to anything. Ask for them while you are still quoting the job.

Send the Grade and the Section

Send the grade or the designation on the drawing, the section you need, and the finished tool behind it.

  • Back comes the grade confirmation
  • The delivered condition with its hardness window
  • And the numbered heat treatment route for that grade
  • Inside 24 hours on a working day

If a document is the easier place to start, ask for a recent EN 10204 3.1 MTC on a grade you already carry and read the delivered hardness against the window above.

Desk hours
09:00 to 18:00 GMT+8, Monday through Friday
Also ask for
A recent EN 10204 3.1 MTC on a grade you already carry, in the same message

Send it to the technical desk

Reply in 24 h

Send the grade and the section

The grade or the designation on the drawing, the section you need, and the finished tool behind it.