Skived
/glossary/skivedInternal surface machined by cutting tool to remove imperfections and improve finish.
A skived tube has had a thin layer cut from the bore with a defined tool, then usually roller-burnished (SRB). Dada Nagar hydraulic-cylinder shops, about 8 km from the Bartan Bazar yard, order it on DIN 2391 ST52 / EN 10305-1 E355. Typical SRB roughness on the hydraulic-cylinder pages is Ra 0.2-0.4 μm. It is not honed-bore unless the drawing says honed. Skived tube is quoted ex-warehouse Kanpur with GST 18% extra as the budgeting basis, and the tax invoice applies the rate in force.
In detail
Skiving is a machining process that uses a cutting tool to remove a thin layer from the internal surface of a tube, eliminating internal weld beads, scale, or surface imperfections. Unlike honing which abrades the surface, skiving cuts with defined geometry. Skived and roller burnished (SRB) tubes combine skiving with cold working for superior internal finish. The process is used for hydraulic cylinders, honed tube pre-processing, and applications requiring specific internal surface characteristics.
What skiving is, and what it is not
Skiving is a cut. A carbide head peels a chip from the ID to correct size and roundness. Roller burnishing then plastic-smooths the peaks and work-hardens the skin. The pair is sold as skived and roller-burnished, SRB. Honing is a different process: abrasive stones leave a cross-hatch that holds oil.
The starting tube is almost always cold-drawn seamless, DIN 2391 ST52 or EN 10305-1 E355, often BK+S (stress-relieved). CDW welded tube is cover-tube stock in Dada Nagar, not the seal bore. ERW with a residual ID bead is the wrong starting point unless the drawing allows a scarfed weld and a later cut.
Skived is not a coating. It is not phosphated OD finish. It is not chrome on the rod. It is not H8 by itself: H8 and H9 are ISO 286 bore classes that must be written next to the process. A mill can skive to H9 and still miss an H8 drawing.
If the drawing says honed, do not accept SRB without engineering approval. Some seals want the cross-hatch. Some high-volume lines prefer the burnished skin. Copy the seal supplier note onto the RFQ.
Buying skived cylinder tube in Kanpur
Dada Nagar is the local barrel cluster. Shops there take ST52 BK+S, H8 or H9, with a per-tube dimension report and a roughness call-out against Ra ≤ 0.4 μm on the DIN 2391 ST52 product page. Panki (about 12 km) takes some of the same stock for press and mobile-equipment cylinders. Intra-Kanpur freight is rolled into the per-kg quote. Yard pickup against challan is still common.
Skived lots leave the Kanpur yard on the daily dispatch that covers Uttar Pradesh, Bihar, Madhya Pradesh, Delhi NCR and Uttarakhand. Ask the quotation to state the dispatch date for each stocked size; stocked sizes leave from the Kanpur yard. Honed finishing is a separate line on that mill route.
Indicative DIN 2391 bands are on the precision tube price list: a 76.0 mm OD × 5.0 mm wall row is ₹96-120 per kg as of 24 May 2026. Ask for SRB versus honed as two lines on the quotation.
See skived and roller-burnished tubes, DIN 2391 ST52, hydraulic cylinder industry, and precision tubes, hydraulic applications. Printing-cylinder work in Kanpur is a different bore spec; do not mix those RFQs.
A Dada Nagar shop that picks up at Bartan Bazar still needs the MTC and the roughness report in the same envelope as the challan. Do not let the mill post the profilometer trace a week later; the inspector at the cylinder shop will not wait. Daily dispatch from Kanpur covers Lucknow and the rest of Uttar Pradesh, Bihar, Madhya Pradesh, Delhi NCR, and Uttarakhand.
Who should order SRB, and who should order honed
Order SRB for repeatable hydraulic-barrel production where cycle time and a smooth, work-hardened bore matter. Hydraulic-cylinder pages treat SRB as Ra 0.2-0.4 μm after honing or skiving and roller burnishing. The DIN 2391 ST52 product page offers H8 with Ra ≤ 0.4 μm as the standard SRB call-out, and Ra 0.2 μm as a premium. Order honed when the drawing names a cross-hatch, when the batch is a repair barrel, or when H8 geometry is tighter than the SRB mill will guarantee. Straightness on that product page is 1 mm per metre or better; length is typically 6 m random or cut-to-length.
For an ISO H8 hole-basis bore, the lower deviation is zero and the tolerance zone extends in the positive direction; it is not a symmetric plus/minus band. The numeric upper deviation depends on the nominal-size step in the applicable ISO 286 table, so copy the drawing or a licensed standard table rather than inventing a millimetre figure. State H8 or H9 and the Ra limit separately, then verify both on the inspection report.
Do not order skived tube for IS 1239 water lines, GI hydrants, or boiler superheaters. Those are different families. Do not order SRB as a substitute for chrome rod. The rod is a separate item.
Wall after skiving is what the pressure calculation must use. Skiving removes stock. Design on minimum wall after finishing, not on the mother-tube nominal wall.
Honed versus skived and roller-burnished
The table restates the precision-tube cluster comparison so a Kanpur buyer can pick a process before the PO. Roughness language on this site is Ra per ISO 4287. ISO 21920-2:2021 is the current ISO profile-parameter standard that revises ISO 4287:1997 (ISO catalogue retrieved 2026-09-03). Local RFQs still write Ra.
| Attribute | Honing | Skived + roller burnished (SRB) |
|---|---|---|
| Process | Abrasive stones, cross-hatch | Cut by skiving, then roller smoothing |
| Typical Ra on this site | 0.2-0.4 μm (H8 pages also state ≤ 0.4 μm) | 0.2-0.4 μm; 0.2 μm as a premium call |
| Bore class | H8 or H9 (ISO 286) | H8 or H9 if specified; not automatic |
| Best fit | Small batches, repairs, named cross-hatch | Production barrels, large-bore, short cycle |
| Kanpur stock note | Honed: may add finishing lead time over SRB | SRB: stocked sizes leave from the Kanpur yard |
Straightness on the DIN 2391 ST52 product page is normally 1 mm per metre or better. Length is typically 6 m random or cut-to-length. Ask for the dimensional report to state ID, roundness, and straightness per metre, not only OD.
How to specify a skived bore on an RFQ
A line that reads "100 × 90 hydraulic tube" is how disputes start. Say whether that is OD × ID or OD × wall, whether the bore is skived, honed, or as-drawn, and whether the class is H8 or H9.
- Tube: DIN 2391 ST52 or EN 10305-1 E355, delivery BK+S unless the drawing says otherwise.
- Size: OD × ID after finishing, or OD × wall with finishing stock stated. Quantity, cut length, machining allowance.
- Bore: skived and roller-burnished, H8 or H9, Ra max in μm. Name ISO 4287 if that is the drawing language.
- Straightness, roundness, and a per-tube dimensional report. Profilometer trace for Ra on SRB / honed tubes.
- ID uncoated. OD may be phosphated and oiled. Caps on both ends.
- Documents: EN 10204 3.1 MTC, heat number, roughness report. TPI if the OEM ITP names it.
- Delivery: ex-warehouse Kanpur, GST 18% extra, lined cradles. No loose stacking on the truck.
Worked mass example for a 76 × 5 mm barrel
Use the site formula once: W = (OD − t) × t × 0.02466 kg/m. For the 76.0 mm OD × 5.0 mm wall row on the precision price list, W = (76.0 − 5.0) × 5.0 × 0.02466 = 71 × 5 × 0.02466 = 8.75 kg/m. A 6 m length is about 52.5 kg.
At ₹96-120 per kg DIN 2391 (24 May 2026, ex-warehouse Kanpur, GST 18% extra), that 6 m tube is 52.5 × 96 = ₹5,040 to 52.5 × 120 = ₹6,300 before GST, freight, and any SRB premium. Skiving removes a chip, so finished-bore mass is slightly below the mother-tube theoretical mass. The Kanpur yard weighment, not the theoretical figure, is the invoiced mass for a skived lot.
Pressure design must use minimum wall after the cut, not 5.0 mm if the skiving pass takes the ID out. Put remaining wall on the drawing before the RFQ, not after the barrel is welded to ports.
Common mistakes on skived-tube orders
In practice, the first error is "honed" on the drawing and SRB on the invoice. Get a written substitution before dispatch. Seal suppliers are not interchangeable on texture.
The second error is an uncapped bore on a monsoon truck from Kanpur to Lucknow or Patna. Flash rust on an SRB skin is scrap. Caps and oil are part of the product.
The third error is using CDW as the seal bore because it is cheaper. Dada Nagar cover tubes can be CDW. The piston-seal ID is CDS, then skived or honed.
The fourth error is skipping the roughness report. An MTC 3.1 proves chemistry and BK+S. It does not prove Ra 0.4 μm. Ask for the profilometer trace.
The fifth error is designing on nominal wall. After skiving, the remaining wall is what Barlow and the cylinder standard see. Record it.
Standards for skived hydraulic tube
DIN 2391-1:1994 and EN 10305-1:2016 govern the mother tube. EN 10305-4:2016 is the hydraulic-power-system part. ISO 286-1:2010 is the H8/H9 code system. EN 10204:2004 is the inspection document. Those designations are the ones already listed on the precision-tube cluster.
ISO 21920-2:2021, Geometrical product specifications (GPS), Surface texture: Profile, Part 2, is the current ISO profile-parameter standard (ISO catalogue retrieved 2026-09-03). Its life-cycle list shows ISO 4287:1997 as withdrawn and revised. Kanpur RFQs on this site still write Ra per ISO 4287. Put the drawing's parameter on the PO so the mill and the inspector use the same ISO number.
There is no BIS skiving standard on this site. The process is a finishing route, not a material grade. Hydraulic barrels are not IBR pressure parts. Form III-B is the IBR certificate for tubes and Form III-C is the certificate for boiler mountings and fittings; keep those lines on boiler SA213 RFQs, not on a cylinder-bore PO.
Where you'll meet this in procurement
You will meet Skived in manufacturing notes, surface-finish call-outs, and precision-tube RFQs. Confirm that Skived 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
- Product catalogue
- Skived and roller-burnished tubes
- DIN 2391 ST52 hydraulic tube
- Hydraulic cylinder industry
- Precision tubes, hydraulic applications
- Precision tube price list
- DIN 2391 vs EN 10305
- Steel pipes in Kanpur
- Kanpur steel market
- Phosphated vs galvanised precision
- Request a quotation (RFQ)
- Back to full glossary
Key points
- Skiving cuts the bore; roller burnishing smooths it. Honing abrades a cross-hatch. They are not automatic substitutes.
- Write H8 or H9 and a Ra limit. Hydraulic-cylinder pages on this site treat SRB as Ra 0.2-0.4 μm.
- Dada Nagar, about 8 km from the yard, holds the Kanpur barrel shops that finish skived tube.
- Mass for a 76 × 5 mm tube is 8.75 kg/m from (OD − t) × t × 0.02466. Design on wall after skiving.
- Pricing is ex-warehouse Kanpur with GST 18% extra. Cap the bore for dispatch across UP / Bihar / MP / Delhi NCR / Uttarakhand.
Frequently asked questions
Sources
- DIN 2391-1:1994. Seamless precision steel tubes. Technical delivery conditions (Deutsches Institut für Normung)
- EN 10305-1:2016. Steel tubes for precision applications. Seamless cold-drawn tubes (European Committee for Standardization (CEN))
- EN 10305-4:2016. Seamless cold-drawn tubes for hydraulic and pneumatic power systems (European Committee for Standardization (CEN))
- ISO 286-1:2010. Geometrical product specifications. ISO code system for tolerances on linear sizes (International Organization for Standardization)
- ISO 21920-2:2021. GPS. Surface texture: Profile. Part 2: Terms, definitions and surface texture parameters (revises ISO 4287:1997) (International Organization for Standardization)
- EN 10204:2004. Metallic products. Types of inspection documents (European Committee for Standardization (CEN))