DIN 2391 St52 Cylinder Tubes — Honed & Skived-Burnished

DIN 2391 St52 — mapped in current procurement to EN 10305-1 E355 — is a precision cold-drawn seamless tube designation used for hydraulic-cylinder barrels. Honed and skived-and-roller-burnished finishes serve different machining plans, while bore, wall, straightness, roughness and usable length remain drawing-controlled. RP Sales handles Kanpur enquiries by checking the requested schedule against current mill or processor capability rather than presenting a fixed size range as live inventory.

Hydraulic-cylinder builders and printing-cylinder shops in Kanpur, Panki, Jajmau and Unnao should buy this tube from a dimensioned cylinder schedule, not from a generic stock description. RP Sales quotes in INR with GST, payment terms, mill identity, MTC scope and delivery basis stated for the particular order. Bore tolerance, surface finish and cut length are checked before commercial confirmation so the received tube matches the machining plan.

What DIN 2391 St52 is and the EN 10305-1 transition

DIN 2391 was the German standard for seamless cold-drawn precision steel tubes from the 1970s through the early 2000s, when it was superseded by the European harmonised EN 10305 family. EN 10305-1 covers cold-drawn seamless tubes for precision applications, with E235, E255, E275, E355, E410 and E460 being the grade designations. The St52 trade name maps directly to E355 — the same chemistry, the same minimum properties — but Indian OEM datasheets and purchase orders still routinely call out “DIN 2391 St52”, and the mill test certificate will normally reference both designations.

The reason St52 / E355 dominates hydraulic-cylinder service is the balance: 355 MPa minimum yield gives ample wall strength for typical 100 to 350 bar working pressures with reasonable wall thickness; the 490 to 630 MPa tensile band gives good fatigue life under cyclic loading; the controlled chemistry (lean carbon, microalloy-restricted) gives clean machinability after honing without surface tearing.

Bore finish — honed vs skived-and-roller-burnished

Chemistry & mechanical properties

• Carbon (C): 0.22 % max — controlled lean carbon for cold-drawing and machining.
• Manganese (Mn): 1.60 % max
• Silicon (Si): 0.55 % max
• Yield strength: 355 MPa minimum
• Tensile strength: 490 to 630 MPa
• Elongation: 22 % minimum (longitudinal)

Why buy from an Indian distributor for an “import” spec

DIN 2391 St52 is a European designation still common on Indian drawings, while offers may come from Indian and overseas mills. Compare them on a landed basis: tube process, usable length, dimensional tolerance, surface finish, certificate scope, currency, duty, transport and minimum production quantity. RP Sales prepares the Kanpur quotation against those same fields so a locally invoiced option can be compared with an import offer without relying on generic MOQ or lead-time claims.

Buying DIN 2391 St52 tubes in Kanpur

For a Kanpur cylinder shop, the practical sequence is to freeze bore, outside diameter, wall, usable length, H8 or tighter requirement, roughness and honed-versus-SRB process before asking for price. RP Sales checks current availability and any mill production requirement against that schedule. Cut-to-length supply and coordination with a matching chrome-plated rod can be included when the quotation confirms the machining and handling scope.

Budget guidance comes from the dated bands on the precision tube price list; use the update date shown there and request a fresh quotation before budgeting a purchase. The offer should state GST, delivery PIN code, packing, freight responsibility, quote validity and the carrier basis available for the confirmed load. That makes the commercial comparison auditable even when steel prices or transport capacity change.

Read the hydraulic-cylinder application guide and the Kanpur steel market guide, then send the schedule through the RFQ form.

Who should use St52 barrel tube and who should not

E355 precision tube can be considered for hydraulic-cylinder barrels only when the approved cylinder calculation, material specification and manufacturing route select it. Bore, wall, ends, surface finish, straightness, delivery condition, pressure test and fatigue basis must be checked together. Do not assign E355 or E235 from a broad pressure band, bore size or equipment label; the cylinder designer owns that selection.

Do not use St52 barrel tube for boiler or steam service; that duty needs the specified boiler-tube grade and, where IBR certification applies, Form III-B for the tube. Steam pipes use Form III-A, while Form III-C is for boiler mountings and fittings. Do not use precision barrel tube for potable-water or structural framing, where the project will normally specify an appropriate pipe or hollow-section standard. Do not order cold-finished hard temper unless the cylinder design needs the higher yield, since machinability drops.

Finish selection by cylinder duty

Finish and tolerance options per the bore table on this page, reviewed 24 May 2026.

RFQ checklist for St52 barrel tube

A complete barrel-tube line reads: ID and wall or OD (for example 100 mm ID x 10 mm wall), grade DIN 2391 St52 / EN 10305-1 E355, bore finish (honed H8 or SRB), length (6 m random or cut-to-length per the cylinder schedule), and quantity in pieces or MT. State the roughness callout (0.4 or 0.2 µm) and the OD finish where the barrel OD stays visible.

• Dimensions and grade. Give ID, wall or OD, St52 / E355 grade and straightness needs (1 mm per metre or better is standard).
• Bore finish and lengths. Choose honed H8 or SRB, roughness target, and 6 m random versus exact cut lengths per cylinder model.
• Certificates and inspection. State whether the MTC must reference DIN 2391 St52, EN 10305-1 E355 or both, and add the buyer-appointed TPI scope where required.
• Schedule and delivery. Share the full cylinder schedule with monthly off-take, delivery PIN code and whether rods and honing coordination are included.

Worked example: mass calculation for a 100mm-bore cylinder

Take a 100 mm ID x 10 mm wall tube. The OD is 120 mm. Theoretical mass follows W = (OD minus wall) × wall × 0.02466, which is (120 − 10) × 10 × 0.02466 = 27.126 kg/m.

A standard 6-metre length is 27.126 kg/m × 6 m = 162.756 kg. Rounded to one decimal that is 162.8 kg per length. Fifty lengths at 162.756 kg are 8,137.8 kg, which is 8.14 MT after rounding, plus cutting losses. Send this shape of takeoff with the bore, wall, grade and finish confirmed.

Common mistakes and inspection points

In practice, barrel-tube complaints trace to five errors. First, grade mix-ups: E235 ordered where the drawing calls E355. The E-number is the minimum yield in MPa, so the specified yield falls from 355 MPa to 235 MPa, a 120 MPa drop to about two-thirds of the E355 figure, not a halved margin. Second, assuming H7 when the standard offering is H8; call H7 out explicitly. Third, assuming a ground OD when the standard surface is hot-rolled or cold-drawn black scale; order turn-and-grind OD on indent where the design needs it. Fourth, forgetting that straightness is 1 mm per metre or better, which matters on long-stroke cylinders. Fifth, MTCs that reference only one designation where the PO named both.

At receipt, bore-gauge the sampling quantity defined by the inspection plan, check the roughness record against the purchase-order callout, verify heat numbers against the MTC, and inspect tube ends and dunnage for transit dents before signing the lorry receipt. If wooden spacers, end protection or nylon strapping are needed, put that packing scope on the order.

Standards and compliance

EN 10305-1 governs cold-drawn seamless precision tubes in grades including E235 and E355; St52 is commonly mapped to E355 in procurement. DIN 2391 is the superseded German precursor that Indian drawings still cite, so the purchase order must state which designation or dual reference the certificate should carry. Bore tolerance, roughness and delivery condition are likewise ordered requirements rather than attributes to infer from the trade name alone.

Clause references sit in the Sources list below; price bands for this grade live on the precision tube price list.

Key points

• St52 maps to EN 10305-1 E355: 355 MPa yield, 490 to 630 MPa tensile.
• Honed H8 suits bores to about 250 mm ID; SRB suits larger bores and finer Ra.
• Confirm availability and delivery against the exact bore, wall, finish, length, mill and inspection scope.
• The MTC should reference both DIN 2391 St52 and EN 10305-1 E355.
• Never use barrel tube for boiler, steam or potable-water duty.

Sources and references

• EN 10305-1, Steel tubes for precision applications, Part 1: cold drawn seamless tubes in E235 to E460 grades (cited by code and clause; no catalogue URL).
• DIN 2391, Seamless precision steel tubes: superseded by EN 10305-1 in 2002, still cited on Indian drawings (cited by code; no catalogue URL).
• ISO H8 / H7 bore tolerance classes and Ra roughness practice for honed and SRB bores (cited by class; no catalogue URL).
• Price bands for this grade: see the precision tube price list (bands last updated 24 May 2026).
• Cylinder application practice: see the hydraulic-cylinder application guide.

Related catalogue and reference pages: precision tubes overview, hydraulic-cylinder application guide, seamless pipes, precision tube price list, MTC documentation, Kanpur steel market, steel pipes Kanpur, glossary of pipe terms, request a quote.

FAQ — DIN 2391 St52 hydraulic cylinder tube