Technical Reference · Steel Pipe Schedule
Steel Pipe Schedule Chart
Use the schedule chart to map NPS and schedule designation to a verified nominal wall thickness under the correct dimensional standard. Schedule is not a pressure rating; pressure capability requires material, temperature, design code, allowable stress, corrosion allowance, joints, and other project inputs.
- NPS + schedule → wall
- OD context
- Standard & edition
- Unit system
- Schedule ≠ pressure rating
RFQ-readiness: a steel pipe order becomes quotable when the standard/edition, NPS, schedule/wall, quantity and destination are explicit. Use the Pipe Schedule Lookup to confirm the nominal wall, then transfer it to the RFQ — and verify material, grade and service suitability as separate gates.
Price on request — wall, schedule, quantity, grade and standard confirmed from the full verified specification
Interactive decision tool
Pipe Schedule Lookup
Select the dimensional standard and the nominal size, and choose the schedule designation: the lookup returns the nominal wall under that standard, with OD context and a copyable schedule line for the RFQ. Schedule is a wall series — never a pressure class.
Verification signal
Governing dimensional standard required
No schedule wall is shown without a stated dimensional standard and edition. Select the governing standard — for example ASME B36.10 — so the lookup identifies the dimensional reference the wall answers to. The wall is a nominal value: it never establishes pressure rating, material, grade or service suitability.
Scope boundary
Schedule is a nominal wall series — it is not a pressure rating, a material, a grade or a wall tolerance. This lookup returns the nominal wall under a stated standard/edition for specification and quantity preparation; pressure capability, material, grade and service suitability are confirmed separately against the governing design code and the mill certificate.
Method & data conditions
How this chart derives its schedule wall
Every value is presented under a stated dimensional standard, size, schedule and unit basis, with source, method, applicability and limits made explicit.
Map NPS + schedule to a wall, openly. The schedule wall is read from the standard’s schedule table for a stated NPS, and every result names the standard, size and schedule. It is a nominal dimensional value for specification and quantity preparation — never a pressure class.
OD context, not a substitution. NPS fixes the nominal outside diameter under the standard, so the wall moves with the schedule while the OD stays. Presenting the OD alongside the wall keeps the size decision explicit and prevents a wall being read off a partial chart without the size.
Unit coherence without false precision. Inch-pound and SI are kept coherent: the wall is shown in both inches and millimetres from the same nominal source. Conversions are labelled so no value gains precision it does not carry.
Schedule is not pressure. The lookup echoes the schedule as a dimensional/ordering field and never derives pressure, wall tolerance, material, grade or service suitability. Those are confirmed against the governing design code, the standard and the mill certificate.
Source and revision
| Reference | Status | RFQ action |
|---|---|---|
| ASME B36.10 — Welded and Seamless Wrought Steel Pipe | Source of the nominal OD and schedule wall subset; edition to be confirmed at quotation | Confirm edition + stated standard |
| Nominal schedule wall per size | Read from the standard’s schedule table for the stated NPS; not a pressure class | Confirm wall + schedule table |
| Project / owner dimensional requirement | May override a chart value for a named project | State project standard + edition |
| Mill test certificate / weigh report | Purchased OD, wall, tolerance and shipment mass per shipped heat | Request MTC + dimensional / weigh report |
The marking, end-condition and measurement shown is part of confirming the purchased OD, wall and length against the standard, the mill certificate and the weigh report.
Worked examples
From schedule input to a verified nominal wall
Example 1 — NPS 10, Schedule 40
Input: ASME B36.10, NPS 10, Schedule 40.
Method: NPS 10 fixes a nominal OD of 10.750 in (273.1 mm); the schedule 40 table carries a nominal wall of 0.365 in (9.27 mm).
Interpretation: This is the nominal wall for it into the RFQ and into the weight estimate. It does not by itself establish the grade or any pressure capability.
Decision impact: The buyer uses the wall for dimension and quantity, and confirms the edition and the mill-tolerance band before ordering. 10 inch steel pipe turns the dimension into a size decision.
Example 2 — size or schedule outside the subset
Input: NPS 16, Schedule 120, ASME B36.10.
Method: 16 and Schedule 120 are outside this page’s reference subset, so no wall is read off a partial chart.
Verification step: The OD and schedule wall must be confirmed against the printed standard/edition. The RFQ carries NPS 16, Schedule 120 and a pending-verification note rather than a guessed wall.
Worked example table — NPS 10, Schedule 40, ASME B36.10
| Step | Value | RFQ field |
|---|---|---|
| Nominal OD (metric) | 273.1 mm (10.750 in) — NPS 10 | NPS / DN / OD |
| Schedule | 40 (wall series, not pressure) | Schedule or wall thickness |
| Nominal wall | 9.27 mm (0.365 in) | Schedule or wall thickness |
| Unit basis | Same source; inch + mm shown from one nominal value | Unit system |
| Verification | Edition, wall tolerance in MTC, grade, pressure rate | Document / inspection |
Standards · walls · size
The schedule wall and its OD basis
Nominal outside diameters and schedule walls referenced to ASME B36.10, paired so the buyer can map NPS + schedule to a wall. Every value is a nominal dimensional basis under the stated standard and edition, confirmed at quotation — it never establishes material, pressure or service suitability by itself.
Schedule is a wall series in the standard
Schedule refers to a nominal wall series defined for a size in the governing standard. Two pipes of the same NPS and different schedule share an OD but differ in wall. Confirm the wall against the printed standard and edition before converting dimension to quantity.
OD is fixed by NPS; wall moves with schedule
NPS fixes the nominal outside diameter; what changes between schedules is the wall and therefore the bore and the mass. Keeping OD and wall explicit prevents a dimension being assumed from a schedule name alone.
Withstand pressure is not set by schedule
Design pressure is judged by the governing design code from material, wall, temperature, allowable stress and corrosion allowance — not by a schedule name. The schedule is an ordering field; the pressure rating is an engineering result.
Tolerances and route are separate
The wall tolerance band, the manufacturing route (seamless or welded), grade and any coating are each specified and tested separately. Confirming the schedule does not confirm the grade or the test obligation.
Core reference table — nominal OD and schedule wall by NPS (ASME B36.10)
Applicability: nominal outside diameters and schedule walls for welded and seamless wrought steel pipe in inch-pound (with millimetre equivalent). Limitation: a dimensional value only — the wall is nominal, and schedule is not a pressure class. Verify the edition and the tolerance band at quotation. RFQ field: NPS/DN/OD + Schedule or wall thickness.
| NPS | OD (in) | OD (mm) | Sched 40 wall | Sched 80 wall | RFQ action |
|---|---|---|---|---|---|
| 1/2 | 0.840 | 21.3 | 0.109 / 2.77 | 0.147 / 3.73 | Confirm edition + wall |
| 3/4 | 1.050 | 26.7 | 0.113 / 2.87 | 0.154 / 3.91 | Confirm edition + wall |
| 1 | 1.315 | 33.4 | 0.133 / 3.38 | 0.179 / 4.55 | Confirm edition + wall |
| 1-1/4 | 1.660 | 42.2 | 0.14 / 3.56 | 0.191 / 4.85 | Confirm edition + wall |
| 1-1/2 | 1.900 | 48.3 | 0.145 / 3.68 | 0.2 / 5.08 | Confirm edition + wall |
| 2 | 2.375 | 60.3 | 0.154 / 3.91 | 0.218 / 5.54 | Confirm edition + wall |
| 2-1/2 | 2.875 | 73.0 | 0.203 / 5.16 | 0.276 / 7.01 | Confirm edition + wall |
| 3 | 3.500 | 88.9 | 0.216 / 5.49 | 0.3 / 7.62 | Confirm edition + wall |
| 4 | 4.500 | 114.3 | 0.237 / 6.02 | 0.337 / 8.56 | Confirm edition + wall |
| 6 | 6.625 | 168.3 | 0.28 / 7.11 | 0.432 / 10.97 | Confirm edition + wall |
| 8 | 8.625 | 219.1 | 0.322 / 8.18 | 0.5 / 12.7 | Confirm edition + wall |
| 10 | 10.750 | 273.1 | 0.365 / 9.27 | 0.594 / 15.09 | Confirm edition + wall |
Conversion and tolerance context
Coherent unit handling and an evidence warning: the wall is shown in both inches and millimetres from the same nominal source, with the unit basis stated. Tolerances on the wall are set by the standard and move the dimension within a small band; they are never added to the chart as if they were a pressure margin.
| Basis | Value / method | Evidence warning | RFQ field |
|---|---|---|---|
| Schedule wall | Nominal wall per NPS + schedule under the standard | Schedule is not a pressure class | Schedule or wall thickness |
| Unit conversions | in ⇄ mm from one nominal source, labelled | Keep one stated unit system | Unit system |
| Tolerance | Wall tolerance band per the standard | Never read as a pressure margin | Inspection / document |
Verify scope before committing to a grade or route
The schedule wall does not pick the grade. Confirm the product-standard scope and ordering fields — API 5L and ASTM A106 — before committing. Matching a schedule alone never establishes material, grade, pressure rating or service suitability.
Verification & misuse controls
Common schedule errors and when review is required
Schedule treated as a pressure rating
A schedule name alone does not establish pressure capability. Pressure requires material, wall, temperature, design code, allowable stress, corrosion allowance and joints. Flag any need to read pressure from a schedule as an engineering step, not a chart lookup.
Wall read without the size or standard
A schedule fixes a wall only for a stated NPS under a stated standard. Reading a wall without the size, or without naming the standard/edition, is an invalid substitution. Always carry standard, NPS and schedule together.
Mixing unit systems
A wall in inches with an OD in millimetres, or a millimetre wall with an inch bore, produces false precision. Keep one stated unit system per calculation and label conversions.
Uncertainty — unverified standard/edition
If the governing standard/edition is not named, or the size is not in an authoritative reference, treat the wall as unverified. Request the mill certificate and a dimensional/tolerance check rather than reading a wall off a partial chart.
Engineering review boundary
Where a wall must also guarantee pressure capability, material or grade for a design, the decision moves past a schedule resource to the design engineer and the governing code. This page does not cross that line.
Where a wall must also guarantee pressure capability, material or grade for a design, the decision moves past a schedule resource to the design engineer and the governing code. This page does not cross that line.
Selection handoff
Carry the verified schedule wall into the Steel Pipes path
The schedule wall is one input. Connect it to the Steel Pipes product, size, grade and application paths, and to the cross-product steel size charts pillar.
Steel Pipes hub. The Steel Pipes page holds product form, material, grade and standard paths — change any of them without losing the qualified schedule context.
Cross-product pillar. Compare this schedule member with the approved steel size charts topic while preserving the technical boundary: sizes and schedules inform supply and quantity, not pressure or service fit.
Wall to grade. A specified schedule/wall is only one line. The 10 inch steel pipe size and API 5L / ASTM A106 grade paths confirm the ordering fields before commitment.
The wall basis is nominal; grade, wall tolerance, coating mass and the actual shipment mass remain separate gates confirmed against the standard and the weigh report.
Related references
Pair the schedule wall with the reference you use
Steel Pipe Dimensions Chart
Confirm the NPS/OD and the full dimensional row that the schedule wall answers to before converting dimension to quantity.
Open referenceSteel Pipe Weight Chart
Once the wall is verified, use the weight chart to extend the size to a nominal bare-pipe mass for estimating and logistics.
Open referenceNPS to OD Conversion Chart
Translate NPS to nominal outside diameter when the requirement is stated in one convention and the stock line in another — verify the edition first.
Open referenceMarkets
Steel pipe schedule across the GCC
Noor Deira Steel coordinates steel pipe supply, documentation and delivery for buyers across the GCC, on a verified nominal wall basis.
United Arab Emirates
Domestic project coordination and documentation.
Carry the verified NPS, schedule, wall, standard/edition, quantity and destination into the RFQ so the commercial team can confirm the dimensional basis, document set and delivery for site or stockist.
Saudi Arabia
Project specification and import documentation.
State the standard/edition, NPS, schedule, wall, quantity, destination and delivery base so the quotation matches the requirement and documents stay aligned.
Qatar
Project specification and delivery.
Confirm standard/edition, NPS, schedule, wall, quantity and delivery window so the estimate and logistics stay aligned to the order.
Kuwait
Specification and import documentation.
Provide destination and Incoterm so the document and delivery plan can align with the verified wall basis.
Bahrain
Project-grade specification.
Confirm contract terms, standard/edition, NPS, schedule, wall and delivery base before quotation.
Oman
Energy and industrial project supply.
Provide destination, required documents and delivery date so the quotation can be fixed on the verified wall basis.
Expert insight
Which wall does the selected schedule represent — and what does that not prove?
A nominal schedule wall, clearly scoped
For the chosen NPS and schedule under a stated standard, the schedule table returns a nominal wall, and the associated OD is fixed by the size. ASME B36.10 — Welded and Seamless Wrought Steel Pipe — standardizes dimensions for welded and seamless wrought steel pipe for high- or low-temperature and pressure service; it identifies the schedule wall that answers the size. Reference reviewed 2026-09-04; the ASME page identifies B36.10-2022.
A dimensional standard does not by itself establish material grade, project design pressure, corrosion allowance, or fitness for a specific service.
ASME B36.10 — Welded and Seamless Wrought Steel Pipe reference
Buyer implication — verify in the RFQ
The buyer can use the schedule wall for dimensional or quantity preparation only after the standard/edition row and the wall are verified. Material and design-code checks remain separate gates before service acceptance: wall tolerance, grade/PSL type, pressure rating and coating mass are each confirmed against the governing standard, the design code and the mill/weigh certificate.
Carry the verified NPS, OD, schedule, wall and quantity into the RFQ, and state the destination, Incoterm and delivery date so the quotation is built on an auditable nominal wall basis rather than a guessed value.
Why this approach
A nominal schedule wall that cannot quietly drift
Assuming a wall from a schedule name alone
The lookup returns a wall only for a stated NPS under a stated standard, and labels it nominal, so a schedule never silently implies a dimension it does not carry.
A specifiable wall that documents the standard, size and schedule that produced it, for a defensible RFQ.
Treating schedule as a pressure rating
Every result states that schedule is not a pressure class and that design pressure is an engineering result from the governing code, material and wall.
A clear handoff of the wall decision to the design engineer, with no pressure claim left implicit in the RFQ.
Mixing inch-pound and SI values
The wall is shown in both inches and millimetres from the same nominal source, and unit coherence is stated rather than blended.
A dimension another engineer or buyer can re-run and audit against the named method and unit system.
Reading a wall off a partial chart without an authority
Only the reference subset tied to ASME B36.10 is carried; unsupported sizes and schedules force a verify-against-standard path rather than a guessed number.
A copyable schedule line that names source, edition, size, schedule and unit basis for an auditable RFQ.
Hiding quantity and destination inside a vague request
The RFQ path turns standard/edition, NPS, schedule, wall, quantity, destination and Incoterm into an explicit payload.
A logistics-explicit quotation built on a verified nominal wall basis rather than a guess.
Order path
From schedule enquiry to closed-out delivery
- 1
Requirement
Input · NPS or OD, schedule, standard, unit system.
Outcome: Dimensional basis stated; size identified.
- 2
Wall lookup
Input · NPS and schedule under the stated standard.
Outcome: Nominal wall confirmed from the schedule table.
- 3
OD & quantity
Input · OD context and length/count.
Outcome: Size and quantity explicit.
- 4
Quotation
Input · Quantity, Incoterm, destination, date.
Outcome: Availability and pricing on request.
- 5
Inspection & weighing
Input · Dimensional, tolerance, test and weigh checks.
Outcome: OD, wall, length and mass reconciled to the mill ticket.
- 6
Packing
Input · Bundling, tagging, lashing.
Outcome: Bundled and tagged by size, schedule, material and lot.
- 7
Shipping
Input · Incoterm, port, documents.
Outcome: Coordinated to destination.
- 8
Delivery & follow-up
Input · Site handover, closed-out docs.
Outcome: Handed to site with documents.
FAQ
Steel pipe schedule — the questions buyers ask
Which standard controls the values shown in this Steel Pipe Schedule Chart resource?
The page maps NPS and schedule to a nominal wall under a stated dimensional standard — referenced to ASME B36.10 — Welded and Seamless Wrought Steel Pipe — and requires you to name the governing standard and edition before any value is shown. The chart identifies its source and never implies a dimension or wall is authoritative on its own; the edition and any project-specified standard are confirmed at quotation.
Why can the same NPS have different wall thicknesses or weights?
NPS fixes the nominal outside diameter, but the wall — and therefore the bore and the mass — changes with the schedule. Two pipes of the same NPS and different schedule share one OD yet differ in wall, cross-section and unit mass. This is why the lookup pairs the schedule with the size and the standard rather than assuming a single fixed wall for a size.
Does schedule by itself determine pressure rating?
No. Schedule is a nominal wall series in the dimensional standard; it does not by itself establish pressure capability. Design pressure is judged by the governing design code from material, wall, temperature, allowable stress, corrosion allowance and joints, not by a schedule name. The lookup states this boundary explicitly and hands the pressure decision to the design engineer and code.
How should metric and inch-pound values be handled in an RFQ?
Keep the unit system coherent and state it in the RFQ. The page shows the wall in both inches and millimetres from the same nominal source and labels conversions so there is no false precision. Never mix a millimetre wall with an inch OD, or state a schedule without the size and standard, without being explicit.
Which result should be copied into the RFQ and which values still require engineering verification?
Copy the verified schedule line — NPS, OD, schedule, nominal wall, the standard/edition-to-be-confirmed and the quantity — into the RFQ. Material, grade/PSL type, wall tolerance, pressure rating, coating mass and the actual shipment mass are separate: they are confirmed against the governing standard, the design code and the mill/weigh certificate, and are never read off a schedule chart alone.
Request a quote
Send the verified steel-pipe specification for RFQ
Need a verified steel pipes specification? Send grade, size, quantity and destination for technical RFQ support. Price remains on request; the nominal wall basis, availability, documents and lead time are confirmed from the full, verified specification.
What to send
The more fields you complete in the Pipe Schedule Lookup, the faster the commercial team can confirm availability, documents and lead time. Paste the copied schedule line straight into the message, or use the form fields below — and keep the grade/PSL type, wall tolerance and service suitability checks separate.
Response & documents
Response times, certificate sets and lead time are confirmed per project. No stock, origin or price figure is published; the nominal wall basis is confirmed against the mill/weigh report at order.
Formula & method
How a schedule wall is established
Schedule table lookup
The wall is read from the standard’s schedule table for a stated NPS and schedule. The method names the standard, edition, size and unit basis — it is a nominal value, not a pressure class.
OD fixed by NPS
NPS fixes the nominal OD; the schedule moves the wall and therefore the bore. OD and wall are presented together so the size decision is not inferred from a schedule name alone.
What is never derived
Pressure capability, material, grade/PSL type, wall tolerance and coating mass are not derived here. They are confirmed against the governing design code, the standard, the mill certificate and the weigh report.
More worked examples
Decision impact of a verified nominal schedule wall
NPS 6, Schedule 80 — higher wall, same OD
Input: ASME B36.10, NPS 6, Schedule 80.
Method: OD stays 168.3 mm; Schedule 80 carries a nominal wall of 10.97 mm, thicker than Schedule 40’s 7.11 mm.
Action: Confirm the wall and the mill-tolerance band before ordering; a thicker wall changes the bore and the mass, so carry it into the weight estimate and the RFQ.
Schedule as an ordering field, not a margin
Input: A buyer asks for “Schedule 40 pipe”.
Method: The schedule fixes a wall series only with the NPS and the standard; it says nothing about the grade or the withstand pressure.
Action: Carry the grade, standard, NPS, schedule, wall, quantity and destination into the RFQ so the quotation is built on a verified wall basis — never read a pressure margin off a schedule chart.
Reference
Downloadable and printable reference
Print the reference table
The nominal OD and schedule wall table on this page is the printable subset. Confirm the full size range, the wall and the edition against the printed ASME B36.10 before ordering.
Primary source
ASME B36.10 is the governing dimensional reference (reviewed 2026-09-04; B36.10-2022). Verify the edition at quotation.
Documents
Request the mill test certificate and the dimensional and weigh report with every consignment so OD, wall, length and mass are traceable to the shipped heat.