What is DD12 forming steel?
DD12 tightens the DD11 specification for drawing: carbon down to 0.10 %, manganese to 0.45 %, phosphorus and sulphur to 0.035 %, yield window 170–320 MPa, tensile ceiling 420 MPa, elongation 30 %, and — new at this level — a non-ageing guarantee for six months, so the skin-passed strip does not develop stretcher strains on a stretched surface. Hot-rolled drawing grades are used where a part is too thick for cold-rolled sheet (2–6 mm) but needs to be pressed with some draw depth: wheel rims and discs, drawn cross-members and brackets, agricultural pans, gas-bottle feet, formed housings. In the die DD12 behaves like a DC03: shallow draws to a ratio of about 1.8, stretch-forming and embossing without orange-peel. It is always supplied pickled and oiled — scale would ruin a drawing die. Because mills roll DD12 only against orders and DD13 (the next level) is a stock item at the same price class, most enquiries end with DD13 delivered.
Chemical composition
| Element | C | Mn | P | S |
|---|---|---|---|---|
| max. % (ladle) | 0.10 | 0.45 | 0.035 | 0.035 |
Typical heat: C 0.03–0.05, Mn 0.20–0.30, Al-killed.
Mechanical properties and formability
| Property | Requirement | Typical value | Note |
|---|---|---|---|
| Yield strength ReH | 170–320 MPa (≤ 340 below 2 mm) | 200–260 MPa | |
| Tensile strength Rm | ≤ 420 MPa | 320–380 MPa | |
| Elongation A80 | ≥ 30 % | 33–38 % | |
| Bend radius | 0.5 × t | passes | |
| Ageing | non-ageing 6 months | guaranteed |
Equivalent grades
| System | Grade | Note |
|---|---|---|
| DIN 1614-1 (old) | StW 23 | historic German |
| EN 10111 (1998) | DD12 | previous edition |
| JIS G3131 | SPHD | |
| ASTM A1011 | DS Type B | |
| GB/T 3273 / 5213 | SPHD |
Pickling, oiling and surface
| Condition | Process | Surface | Best for |
|---|---|---|---|
| Black (HR, as-rolled) | none — mill scale left on | blue-black oxide, 10–40 µm, flakes when bent | welded structures, plate to be blasted, hidden parts |
| HRPO (pickled & oiled) | HCl pickling of coil, rinse, light oil | uniform grey-metallic, scale-free, Ra ≈ 1–3 µm | forming, painting, roll-forming, tube making, visible parts |
| HRP / HRPO skin-passed | pickling + temper pass | flatter, tighter gauge, no Lüders lines | pressing, blanking, precision parts |
| Dry (pickled, unoiled) | pickling, no oil | bare, rusts within days | immediate galvanizing or welding only |
Turkish trade names: siyah sac = black hot-rolled, HRP / asitli sac = pickled & oiled. The steel grade (S235JR, DD11 …) is the same under both surfaces; only the finish differs.
Thickness range and stock sizes
| Thickness | Widths × lengths | Availability |
|---|---|---|
| 1.5–3.0 mm | coil 1 000 / 1 250 / 1 500 mm | to order 2–3 weeks |
| 4.0–6.0 mm | coil 1 250 / 1 500 mm; sheet 2 500 / 3 000 | to order 2–3 weeks |
| any | DD13 HRPO from stock as substitute | 3–5 days |
Weight per m² and per sheet
| Thickness | kg/m² | 1 000 × 2 000 (kg) | 1 250 × 2 500 (kg) | 1 500 × 3 000 (kg) |
|---|---|---|---|---|
| 1.5 mm | 11.78 | 23.6 | 36.8 | 53.0 |
| 2 mm | 15.70 | 31.4 | 49.1 | 70.7 |
| 2.5 mm | 19.63 | 39.3 | 61.3 | 88.3 |
| 3 mm | 23.55 | 47.1 | 73.6 | 106.0 |
| 4 mm | 31.40 | 62.8 | 98.1 | 141.3 |
| 5 mm | 39.25 | 78.5 | 122.7 | 176.6 |
| 6 mm | 47.10 | 94.2 | 147.2 | 212.0 |
Uncoated; tolerances to EN 10051.
Forming, welding and painting
Shallow drawing to about 1.8, stretch-forming and embossing with drawing oil and polished tools; hems and flanges at 0.5 × t. Welds without preheat, soft ductile joints. Paint after degreasing — the pickled surface needs no blasting. Use within the non-ageing period for parts with visible stretched surfaces.
Where it is used
- Wheel rims and discs (with DD13 for the deeper draws)
- Drawn cross-members, brackets and reinforcements
- Agricultural pans, hoppers and formed covers
- Gas-bottle feet and collars
- Pressed housings and casings in 2–6 mm
- Formed parts for construction machinery
DD12 vs DD11 vs DD13
DD11 bends; DD12 draws; DD13 deep-draws — yield windows 170–340, 170–320 and 170–310 MPa, elongation 28, 30 and 33 %. DD13 is stocked and exceeds DD12 in every respect at a few dollars more, so order DD12 by name only when the specification requires it.
Price
DD12 is priced about 10 USD/t over DD11 HRPO; the band below is indicative FOB Istanbul for mill-order coil.
Bands from our weekly export list (September 2026), FOB Istanbul, full-container quantities, excluding freight and certificates. Firm price per project on RFQ within one working day.
Export and packing
We load DD12 forming steel as slit or master coils on cradles (VCI paper, strapped, 5–25 t) or as cut-to-length sheet on skids (≤ 3 t, interleaved, edge boards); a 20' container carries one coil to 20 t, a 40' HC two coils or 24 t of sheet. HS 7210 / 7209 / 7208.
| Term | Detail |
|---|---|
| MOQ | One coil (10–25 t) |
| Incoterms | FOB Istanbul · CIF / CFR Gulf, Africa · DAP EU, Balkans, Iraq, Caucasus · DAP Aktau |
| Lead time | To order 2–3 weeks; DD13 from stock as substitute |
| Packing | Coil eye-to-sky, VCI paper; sheet on skids |
| Container / truck | 20' one coil ≤ 20 t; 40' HC two coils |
| Documents | Invoice, packing list, EN 10204 3.1 (3.2 on request), certificate of origin; SASO / SONCAP / PVoC on request |
| Payment | 30% advance, balance against B/L copy; L/C at sight for orders above 100 t |
Certificates and testing
DD12 forming steel is delivered with the mill certificate EN 10204 3.1 — heat number, ladle analysis, tensile and impact results and the delivery condition. Third-party 3.2 certification (Lloyd's, BV, TÜV, SGS), ultrasonic testing to EN 10160 and extra Charpy tests at a lower temperature are ordered per lot.
How to order
Specify thickness × width, coil or sheet, tonnage, the part (so we can confirm the level) and whether DD13 from stock is acceptable.
Standards
- EN 10111:2008 — DD12, 1.0398
- EN 10051 — tolerances
- EN 10204 3.1
- Former DIN 1614 StW 23
Grades
Grade data sheets (chemistry, mechanicals, equivalents) are on our reference site: DD12 · DD11 · DD13
Frequently asked questions
What is DD12 steel?
The drawing-quality hot-rolled forming steel of EN 10111 (1.0398, ex StW 23): yield 170–320 MPa, elongation ≥ 30 %, non-ageing, pickled and oiled, for pressed and shallow-drawn parts in 1.5–6 mm.
What is the difference between DD11 and DD12?
DD12 has lower carbon and manganese, a narrower yield window (170–320 vs 170–340 MPa), 30 % vs 28 % elongation and a non-ageing guarantee; DD11 is the bending grade.
What is the equivalent of DD12?
DIN StW 23, JIS SPHD, ASTM A1011 DS Type B.
Is DD12 in stock?
It is rolled to order in 2–3 weeks; DD13, which exceeds it, is stocked pickled and oiled at Dilovası.