Cold-drawn
/glossary/cold-drawnTube drawn through tooling below recrystallisation temperature to the ordered standard and condition.
Cold-drawn tube is a prepared hollow pulled through a die and over a mandrel below recrystallisation temperature, then treated to the ordered delivery condition. Dada Nagar hydraulic shops, about 8 km from the Bartan Bazar yard, buy DIN 2391 ST52 / EN 10305-1 E355 this way. ASTM A179/A179M-24 requires the seamless process and cold drawing on heat-exchanger tubes 3.2 to 76.2 mm OD. Offers from RP Sales are ex-warehouse Kanpur, GST 18% extra as the budgeting basis.
In detail
Cold-drawn seamless tube is produced by drawing a prepared hollow through a die and over a mandrel below the steel's recrystallisation temperature, then applying the delivery-condition treatments named by the product specification. EN 10305-1:2016 covers seamless cold-drawn precision tubes with outside diameter D ≤ 380 mm and a specified maximum surface roughness. ASTM A179/A179M-24 covers seamless cold-drawn low-carbon heat-exchanger tubes from 3.2 to 76.2 mm OD. Tolerance, roughness, and strength follow the ordered standard, grade, and condition, not the words cold drawn.
What cold drawing is, and what it is not
Cold drawing is a size-and-finish pass on a hollow that already exists. The mill pulls that hollow through a die and over a mandrel below the recrystallisation temperature. The product specification then names the heat treatment or stress-relief that follows. Hot-finished tube is sized while the steel is still hot and keeps mill scale.
EN 10305-1:2016, Steel tubes for precision applications. Technical delivery conditions. Part 1: Seamless cold drawn tubes (NSAI catalogue, retrieved 2026-09-05), covers circular seamless cold-drawn tubes with specified outside diameter D ≤ 380 mm. The abstract states that those tubes have precisely defined tolerances on dimensions and a specified maximum surface roughness. Typical fields named there are automotive, furniture, and general engineering.
ASTM A179/A179M-24 (store abstract retrieved 2026-09-05) covers minimum-wall-thickness, seamless cold-drawn low-carbon steel tubes for heat exchangers, condensers, and similar apparatus. The cited product page gives a 3.2 to 76.2 mm OD range and requires seamless cold-drawn construction. Apply the tests and property limits from the ordered edition to the ordered size.
Cold-drawn is not a pressure rating. It is not H8. It is not honed-bore and not skived. It is not phosphated. Those are later call-outs. A seamless mother hollow that was never drawn is still seamless. It is not a precision tube.
Who should order cold-drawn tube, and who should not
Order it when the drawing names a precision-tube standard, a heat-exchanger cold-drawn grade, or a dimensional class that hot-finished pipe cannot meet. Dada Nagar cylinder shops take ST52 / E355. For steering columns and shock-absorber tubes, use the site correspondence table: ST37.4 / E235, ST45 / E275, or ST52 / E355, then order the grade named on the drawing. Sugar-mill condensers take SA179 / A179 on OD × minimum wall.
Do not order it as a substitute for IS 1239 water pipe, GI hydrants, or borewell casing. PWD and JJM tenders want class pipe, not DIN 2391. Do not order it as NPS × schedule process pipe; that family is ASTM A106 or A53.
Do not treat BK stock as NBK. The catalogue lists BK (Cold Finished), BKW, BKS, GBK, and NBK as distinct delivery conditions. Read the exact condition definition and property requirements in the ordered specification, then copy the drawing code onto the PO. A designer must approve a condition swap before the mill cuts.
Do not treat cold-drawn as a finished hydraulic barrel. Honing or SRB may still be required for the named bore class and Ra. A tube described only as smooth bore is incomplete for a seal.
Product family and delivery condition
Pick the product standard first, then the condition. The rows below are the families already used on the precision and boiler pages. Roughness and tolerance numbers live in the ordered edition, not in the process name.
| Family | Governing spec | Usual size note | Kanpur buyer |
|---|---|---|---|
| CDS precision | EN 10305-1:2016 / DIN 2391-1:1994 | Circular D ≤ 380 mm on EN 10305-1 | Dada Nagar hydraulic barrels |
| Hydraulic power tube | EN 10305-4:2016 | Seamless cold-drawn for hydraulic and pneumatic systems | Panki press and mobile cylinders |
| CDW | EN 10305-2 / IS 3074 | Welded hollow, then drawn | Cover tubes, not the seal bore |
| Heat-exchanger | ASTM A179/A179M-24 / SA179 | 3.2 to 76.2 mm OD, minimum wall | Sugar-mill condensers |
| Boiler alloy, cold-finished | ASTM A213 / SA213 as specified | Hot-finished or cold-finished as ordered | Panki superheater shops |
The DIN 2391 vs EN 10305 comparison maps legacy DIN BKS to the +LC cold-drawn light delivery condition. It is not a letter of credit. Keep that meaning on the precision RFQ.
How to specify cold-drawn tube on an RFQ
Write a tube line, not "MS pipe heavy." Attach the component drawing. A missing condition is how a BK bundle lands on a weldment that needed NBK.
- Standard and grade: DIN 2391 ST52 or EN 10305-1 E355, EN 10305-4 if hydraulic, A179 / SA179 if condenser, A213 if the drawing says cold-finished alloy.
- Size: OD × ID or OD × wall in millimetres. Tolerance class. Straightness. Quantity and cut length.
- Delivery condition: BK, BKW, BKS / BK+S, GBK, or NBK as on the drawing.
- Bore finish: state as-drawn, honed H8/H9, or skived / SRB. Add an Ra limit when the seal supplier names one.
- Finish: ID uncoated. OD phosphated and oiled only if the drawing allows it.
- Documents: EN 10204 3.1 MTC, heat number, dimensional report. TPI if the OEM ITP names it.
- Delivery: ex-warehouse Kanpur, GST 18% extra, capped ends, lined cradles.
Worked mass on a 63 × 4 mm precision tube
Apply the site mass formula W = (OD − t) × t × 0.02466 kg/m. For the 63.0 mm OD × 4.0 mm wall row on the precision tube price list, W = (63.0 − 4.0) × 4.0 × 0.02466 = 59 × 4 × 0.02466 = 5.82 kg/m. A 6 m length is 34.92 kg.
The DIN 2391 band on that row is ₹98-122 per kg as of 24 May 2026, ex-warehouse Kanpur, GST 18% extra. That 6 m tube is 34.92 × 98 = ₹3,422 to 34.92 × 122 = ₹4,260 before freight and any hone or SRB line.
Forty lengths are 240 m × 5.82 = 1.40 MT. Invoice weighment at the Kanpur yard is the commercial mass. Design pressure still uses the ordered wall and the drawing's allowable stress. The process name does not set a bar rating.
Common mistakes on cold-drawn orders
In practice, the first error is ordering "cold-drawn hydraulic tube" with no grade, condition, or bore class. The mill then ships as-drawn BK. The cylinder shop cannot hone what the drawing never named.
The second error is treating CDW as CDS because both were drawn. CDW starts with a welded hollow. Dada Nagar cover tubes can be CDW. The piston-seal ID is CDS, then honed or skived.
The third error is using a hot-finished boiler hollow as precision stock. Hot-finished tolerances and mill scale belong on SA192 or SA210 water-wall sizes, not on an H8 barrel.
The fourth error is galvanising a finished bore. Outdoor GI stays on IS 4736. Where that standard applies, the amended minimum average zinc mass used on this site is 360 g/m². Keep that finish off a seal ID.
Standards for cold-drawn tube
EN 10305-1:2016 is the seamless cold-drawn precision part. EN 10305-2 is welded cold-drawn. EN 10305-4:2016 is seamless cold-drawn tube for hydraulic and pneumatic power systems. DIN 2391-1:1994 remains the legacy drawing language for ST35 / ST45 / ST52.
ASTM A179/A179M-24 governs seamless cold-drawn low-carbon heat-exchanger and condenser tubes; take its chemistry, mechanical, and test requirements from the ordered edition. ASME SA-179 is the BPVC Section II counterpart used on Indian condenser RFQs.
EN 10204:2004 is the inspection document. ISO 286-1:2010 is the H8/H9 code system when a finished bore is ordered. IBR Form III-B is for tubes; Form III-C is for boiler mountings and fittings. Condenser A179 lots follow the project document list, not a cylinder-bore PO.
Buying cold-drawn tube in Kanpur
Dada Nagar is the local barrel cluster. Shops there take ST52 BK+S with a per-tube dimension report when the bore is finished. Jajmau, about 10 km away, is not a precision cluster; it takes ERW water and process pipe. Keep those RFQs on the ERW pages.
Indicative DIN 2391 bands on the precision list run ₹95-150 per kg by size, ex-warehouse Kanpur, as of 24 May 2026. The 63 × 4 mm row used above is ₹98-122 per kg. See precision tubes for hydraulic applications, DIN 2391 ST52, and seamless pipes in Kanpur.
Stocked precision sizes leave the yard on the 3-7 day band listed on the glossary lead-time entry. Honed finishing is a separate mill line and sits on the longer mill-direct window when the size is not finished in stock.
CDS versus CDW after the draw
CDS starts with a seamless hollow. CDW starts with a welded hollow. Both can be cold-drawn to a tight OD. The seam remains a design fact on CDW. Fatigue and pressure design stay with the engineer.
See CDW tubes in Kanpur when the drawing allows a welded-and-drawn route. See hydraulic cylinder industry when the seal bore must be seamless. A cover-tube RFQ can name IS 3074 or EN 10305-2. A barrel RFQ names EN 10305-1 or DIN 2391 and the bore class. Mixing those two lines on one challan is how a welded seam reaches a seal inspector.
Printing-cylinder work in Kanpur uses a different bore spec than hydraulic SRB. Keep printing cylinder orders on their own PO.
Finishing after the draw
Honing abrades a cross-hatch. Skiving cuts, then roller burnishing smooths. Phosphate converts the OD. None of those finishes is included in the word cold-drawn.
If the ID will be honed or skived after delivery, say so on the RFQ so the mill does not coat the bore. Cap both ends. Lined cradles stop the mouth from picking up scale from an ERW bundle on the same truck.
Wall after a skiving pass is the wall the pressure calculation must use. Design on remaining wall, not on the mother-tube nominal.
Dispatch of precision tube from Bartan Bazar
Ends are capped. Tubes sit in lined cradles. The MTC and the dimensional report travel in the same envelope as the challan. Daily runs cover Uttar Pradesh, Bihar, Madhya Pradesh, Delhi NCR, and Uttarakhand.
Seamless pipes in Lucknow and steel pipes in Kanpur describe city delivery. A mixed lorry can take ERW plus precision when the precision sits in its own cradles.
Send the RFQ with grade, condition, and bore already written. A store that asks for "ST52 whatever is in stock" is how a BK bar lands on an NBK weld jig.
Where you'll meet this in procurement
You will meet Cold-drawn in manufacturing notes, surface-finish call-outs, and precision-tube RFQs. Confirm that Cold-drawn is required for the duty (tolerance, bore finish, or coating), and that the quote states the same process the inspector will verify on receipt.
Related terms
Related resources
Key points
- Cold drawing pulls a prepared hollow through tooling below recrystallisation temperature. The delivery condition then follows the spec.
- EN 10305-1:2016 covers seamless cold-drawn precision tubes with D ≤ 380 mm. ASTM A179/A179M-24 covers 3.2 to 76.2 mm OD heat-exchanger tubes.
- Tolerance, Ra, and strength are not fixed by the words cold drawn. Write standard, grade, condition, and bore class.
- A 63 × 4 mm tube is 5.82 kg/m from (OD − t) × t × 0.02466. The 24 May 2026 DIN band on that row is ₹98-122 per kg.
- Dada Nagar (about 8 km) is the Kanpur barrel cluster. Quotes are ex-warehouse Kanpur, GST 18% extra.
Frequently asked questions
Sources
- EN 10305-1:2016. Steel tubes for precision applications. Technical delivery conditions. Part 1: Seamless cold drawn tubes (D ≤ 380 mm; defined tolerances and specified maximum surface roughness) (CEN / NSAI)
- ASTM A179/A179M-24. Standard Specification for Seamless Cold-Drawn Low-Carbon Steel Heat-Exchanger and Condenser Tubes (3.2 to 76.2 mm OD on the cited product page) (ASTM International)
- EN 10305-4:2016. Seamless cold-drawn tubes for hydraulic and pneumatic power systems (European Committee for Standardization (CEN))
- DIN 2391-1:1994. Seamless precision steel tubes. Technical delivery conditions (Deutsches Institut für Normung)
- EN 10204:2004. Metallic products. Types of inspection documents (European Committee for Standardization (CEN))
- Indian Boiler Regulations, 1950. Forms index: III-A steam pipes, III-B tubes, III-C boiler mountings and fittings (Central Boilers Board, Government of India)