10 mm x 1500 mm Grade 2 Titanium Plate: The Plate-to-Shell Fit-Up and Dimension Chain

10 mm x 1500 mm Grade 2 Titanium Plate: The Plate-to-Shell Fit-Up and Dimension Chain

A 10 mm by 1500 mm Grade 2 Titanium Plate to ASTM B265 is delivered as an ordered width, not necessarily the width the mill rolled. The flat blank length must be computed on the mean diameter: L equals pi times Dm, with Dm equal to the inside diameter plus the measured thickness, or the outside diameter minus that thickness. Computing the blank from the outside diameter alone makes it too long by pi times t, 31.4 mm on a 10 mm plate. Our ASTM B265 plate specification guide, our ordering-by-end-use page and our receiving-weight guide settle identity, standard and settlement; this article works the dimension chain when that plate is rolled into a shell course.

Published charts disagree on thickness band, width tolerance, flatness and camber, so we publish the conflict, eight fit-up rejection triggers and one 14-line verification sheet instead of one invented number. Our B265 plate and sheet page gives the specification context and our plate ordering guide gives the buying context; the drawing revision and the named standard edition govern.

At a Glance: Eight Decisions That Separate a Clean Fit-Up from a Rejected Shell Course

Our Grade 2 B265 supplier page gives the grade context and our EN 10204 3.1 mill certificate page shows a traceable thickness record. A stockholder can certify a heat number, not a blank length it did not calculate for your drawing.

The 1500 Trap: An Ordered Width Is Not Necessarily a Rolled Width

The 1500 on a purchase order is a finished, ordered width, not automatically the width that came off the mill. A wider mother plate or coil may be slit or sheared to 1500 mm, and published charts give mill width and slit width different tolerances. Our plate thickness and form classification page separates the product forms and our plate sheet and coil page shows the wider coil context; treat 1500 mm as a cut result.

An ordered width carries a cutting tolerance, and a slit edge has its own width tolerance, camber, squareness and burr condition that the mill certificate rarely states. Those are fit-up inputs, not material identity. Our zero-cutting and small-batch plate page covers how non-standard widths are produced, and our process equipment buyers guide gives the vessel context.

An ordered width is a cutting result with its own tolerance and edge condition. Name whether 1500 mm is a rolled width or a slit width before you use it as a geometric input.

What matters is the measured width at both edges and mid-length plus the edge condition along the full length, and whether the named edition treats 1500 mm as a mill or a slit width. Our Titanium Plate range lists the product; the drawing revision decides how the width is used.

Where the Tolerance Goes: How 10 mm Plus Tolerance Enters the Mean Diameter

A rolled cylinder is laid out from one identity: the blank length L equals pi times Dm, where Dm equals the finished inside diameter plus the plate thickness, or the outside diameter minus that thickness, and pi is about 3.14159. This is geometry, not tolerance. It becomes a dimension chain because t is the measured mean thickness of the plate you cut, not the nominal 10 mm on the order.

Grade 2 plate is commonly described on our Grade 2 B265 plate page as carrying an asymmetric thickness tolerance with a larger plus side. Measured mean thickness above nominal grows the mean diameter and the required blank length by pi times that deviation; with a fixed blank a thicker plate gives a smaller inside and a larger outside diameter.

If the drawing controls the inside diameter, an under-run ID is the failure; if it controls the outside, an over-run OD drives hi-lo at the circumferential joint. The plus tolerance travels from the thickness gauge into the diameter and the seam. Our B265 plate and sheet page states the specification context and our GB versus ASTM B265 comparison shows the governing edition must be named first.

The Dimension Nobody Measures: pi Times t, 31.4 mm, and the Longitudinal Seam

The common layout error is the wrong diameter in the formula. Computing the blank from the outside diameter makes it too long by pi times t, 31.4 mm on a 10 mm plate; using the inside diameter makes it short by the same amount. Both grow with thickness. These are deterministic arithmetic results, not supplier figures.

A blank too long overlaps and is trimmed and re-bevelled; a blank too short leaves a gap that cannot be pulled together without forcing the roll. Either way the geometric error becomes a fit-up error at the seam. Our what a B16.5 flange hides makes the parallel point, and our WPS and NDT qualification guide shows a weld procedure is qualified separately from the geometry that feeds it.

The neutral axis is an assumption: rolling places it at mid-thickness, press-brake bends use a K-factor near 0.35 to 0.45, and some procedures add an elongation term. We will not print one elongation figure as correct; measure the first-article circumference and close the assumption. Our GTAW shielding guide applies the same discipline at the root pass.

A mean-diameter layout is a calculation; a fit shell is a measurement. Confirm the blank against a measured first-article circumference before the whole course is cut.

After the Slit: Width Tolerance, Edge Quality, Flatness and the Bevel

Which edge becomes the circumference

Only one edge of the plate becomes the circumference: typically the long dimension is cut to L and rolled while 1500 mm becomes the axial course height, though nesting can rotate that by ninety degrees. Our cut-to-size plate stock page and our same-day cut-to-size plate page describe how the blank is produced; the development sheet decides which dimension is critical.

Width tolerance, edge camber and edge quality at the seam

The ordered width carries a one-sided plus tolerance and an edge camber over a stated length; a bowed edge makes the course ends miss a common line and the seam wander. A burr or heat-affected lip must be removed before bevelling or it becomes a root defect. Our WPS and NDT qualification guide and our GTAW shielding guide cover the joint and the root; width and edge condition are the geometry that feeds them.

Flatness as a machining allowance for the bevel

Flatness is not cosmetic once a bevel must be machined: a wavy edge presents a varying stock height, so the bevel angle, root face and land drift along the joint. Published flatness figures disagree, so treat the measured out-of-flat value as machining allowance to remove before bevelling. Our plate sheet and coil page gives the form context and our dimensional standard article shows a standard leaves mating geometry to the drawing.

When the Published Tolerance Numbers Disagree: Publish the Conflict, Not One Value

Ask several sources for the tolerance on a 10 mm plate and you get a spread, not one table: charts divide thickness bands differently and quote symmetric versus asymmetric bands. Presenting any single figure as the correct ASTM B265 value would be false precision. The table below is secondary, not the controlling edition; the governing value is the one named in the purchase order read with the drawing revision.

Our B265 specification page and our GB versus ASTM B265 comparison show why the edition must be named, and our mill certificate page shows the measured thickness that anchors the calculation. Where figures disagree, the measured plate and the signed verification sheet decide.

Two Independent Check Lines: Fit-Up Geometry Here, Area or Weight Settlement There

Whether a plate is settled by area or by weighbridge mass is a commercial question, not a fit-up question; it belongs to the receiving line our receiving-weight guide, our plate weight calculator and our export documentation FAQ already cover. That line decides what the buyer pays; this line decides whether the plate assembles, and a pass on one does not grant a pass on the other.

A plate can be on weight and still fail fit-up. Theoretical mass uses a density near 4.51 grams per cubic centimetre, but mass is an aggregate that cannot see a thickness peak, a bowed edge or a wavy bevel land. A uniformly plus-side plate may be commercially acceptable and geometrically wrong for a fixed blank length. Those are two records with two sign-offs.

The settlement file holds the purchase order, weighbridge ticket and certificate; the fit-up file holds the drawing revision, measured mean thickness, development calculation, width and camber record, flatness and bevel measurements and the signed 14-line sheet. Our hydrostatic test water guide is a downstream gate, not a substitute. When an enquiry asks whether to buy by area or by weight we point to the settlement line; when it asks whether the course will close on the head we work the dimension chain, with our process equipment buyers guide giving the vessel context.

Limitations and Failure Conditions: Eight Plate-to-Shell Fit-Up Rejection Triggers

Trigger 1 - Blank length computed from outside diameter or nominal thickness instead of measured mean thickness

The blank length L must equal pi times Dm using the measured mean thickness from a mapped ultrasonic survey, not the nominal 10 mm or the outside diameter; an unmeasured thickness is a hold. Our Grade 2 B265 plate page gives the product context.

Trigger 2 - Plus thickness tolerance carried into diameter without a re-check of the ID or OD control basis

Confirm whether the drawing controls the inside or outside diameter and measure the rolled course at several stations, because a thicker plate on a fixed blank shifts the controlled diameter. Our B265 specification page names the edition.

Trigger 3 - Ordered 1500 mm width treated as a rolled width with no slit-width or camber record

Measure width at both ends and mid-length plus edge camber over the stated gauge length; a width without its mill-or-slit basis and a straightness figure is incomplete evidence. Our zero-cutting plate page describes how the width was produced.

Trigger 4 - Cut-edge burr, heat-affected lip or edge defect left in the bevel zone

Examine both long edges before bevelling and record the edge-preparation step; burr, a shear-affected lip and laminations become root defects or gap variation. Our WPS and NDT qualification guide covers the joint record.

Trigger 5 - Flatness out of criterion with no bevel machining allowance left

Measure flatness on a surface plate against the drawing clause and confirm the stock left for machining; a wavy edge that consumes the bevel allowance drifts the bevel angle, root face and land. Our plate sheet and coil page gives the form context.

Trigger 6 - Cumulative hi-lo at the head, adjacent course or flange straight flange above the drawing criterion

Measure the offset between the course and the mating part around the full circumference, not at one clock position, because a small longitudinal-seam error compounds into circumferential misalignment. Our what a dimensional standard hides makes the parallel point.

Trigger 7 - Plate substituted by a different thickness band, width or form without a re-cut and re-calculation

Any change of heat, thickness band, ordered width or form resets the measured thickness feeding the blank length, so re-run the calculation and re-cut; a substitute cut to the old blank length is a reject. Our ordering-by-end-use page separates buying from fit-up.

Trigger 8 - Dimension chain reviewed with no signed verification sheet or lost heat-to-course traceability

Reconcile every cut blank, rolled course and weld against the heat number, the drawing revision and the signed 14-line sheet; a course whose thickness map cannot be rebuilt is a reject regardless of a clean certificate. Our EN 10204 3.1 certificate page shows what the mill record proves.

The 14-Line Plate-to-Shell Fit-Up and Dimension Chain Verification Sheet

Line two is often answered with a nominal 10 mm instead of a measured mean. Our mill certificate page and our receiving-weight guide separate material and settlement evidence, our export documentation FAQ covers the paperwork, and our equipment leak repair guide shows the cost of an undocumented joint. A sheet without a signature column is a note, not a record.

Six Verification Actions When Thickness, Width and Flatness Figures Conflict

1. Require every acceptance value to carry its document, revision and clause. Name the ASTM B265 or ASME SB-265 edition, the drawing revision and the grade condition before quoting any band. Our B265 specification guide is a product reference, not the governing clause.
2. State the sample condition and measuring method: hot-rolled or cold-rolled, annealed or as-rolled, and the measured mean thickness from a mapped ultrasonic survey rather than the nominal 10 mm. Our plate ordering guide gives the buying baseline.
3. Publish the development calculation before cutting: the control diameter, the formula L equals pi times Dm, the pi value, the pi times t cross-check and the cut length. A calculation is a prediction; the measured first-article circumference is the record. Our plate weight calculator is a mass tool, not a layout tool.
4. Name who reviews the conflict: buyer quality, fabricator engineer, rolling supervisor and, where the contract calls for it, a third-party surveyor, with authority to accept or hold. Our WPS qualification guide shows qualification is a signed decision.
5. Keep records independent with their own dates: purchase order and MTC, thickness map, development sheet, slit-width and camber record, flatness and bevel measurements, first-article survey and the signed verification sheet. Our EN 10204 3.1 certificate page covers what the mill record proves.
6. Use trigger-based re-verification: any re-cut, heat or thickness-band change, edge re-preparation, rolling-procedure change or opened hold forces reassessment. Our equipment leak repair guide and our equipment layup guide show the downstream cost.

These cost little at planning and a great deal after a course is fitted to a head. We are a stockholder, not the author of your drawing; where supplier charts disagree we give the disagreement and the action. Our hydrostatic test guide is a later gate, not a substitute for the fit-up record.

Summary: Choose a Nominal Layout if, Escalate if, Choose a Re-Measured Layout if

Choose a nominal-thickness layout with a signed development sheet if:

• The purchase order names the standard edition, the grade condition and the drawing revision, and the control diameter is stated as ID or OD.
• A mapped ultrasonic survey gives the measured mean thickness and the development calculation uses it, with the pi times t cross-check attached.
• The ordered 1500 mm width is confirmed as a mill or a slit width, with a width, camber and edge-quality record.
• The flatness and bevel allowance, the rolling first article and the 14-line sheet are signed per line before the course is released.

Escalate to a fit-up hold or a drawing review if:

• A clean mill certificate or a clean weighbridge ticket is the only fit-up evidence offered.
• The blank length was computed from the outside diameter, from the inside diameter, or from the nominal 10 mm rather than a measured mean thickness.
• Published charts disagree on thickness band, width tolerance, flatness or camber and no one has named the governing edition.
• Cumulative hi-lo at the head, the adjacent course or the flange straight flange exceeds the drawing criterion.
• The heat-to-course traceability, the first-article circumference or a signed verification sheet is missing from the file.

Choose a re-measured layout and a re-cut if:

• The plate was substituted by another heat, thickness band, width or form; settle the dimension chain again before rolling. Our zero-cutting plate page covers the non-standard sizes that make this common.
• The design controls an inside diameter for internals or a lining, so a plus thickness deviation cannot be absorbed. Our process equipment buyers guide gives the vessel context.
• The buyer cannot produce a thickness map, a development sheet or a signed verification sheet; set up the shop records first.
• Area-versus-weight settlement is in dispute; keep that on the receiving line and read our receiving-weight guide while the fit-up line stays independent.

The whole subject reduces to one sentence: a nominal size is not a fit, because the drawing tells you what to order while the tolerance chain tells you whether the course will assemble. Send the grade, standard edition, nominal and measured thickness, ordered width and its mill-or-slit basis, control diameter, drawing revision and joint detail. We are a Baoji China Titanium Valley stockholder with roughly 800 tonnes in stock, about 400 tonnes in plate, cutting to non-standard and small-batch sizes from customer drawings. Send the shell drawing and the thickness map. Request a quote →

Frequently Asked Questions

Should the shell blank length use nominal 10 mm thickness or the measured mean thickness?

Use the measured mean thickness from a mapped ultrasonic survey, not the nominal 10 mm. The developed length L equals pi times Dm, and Dm equals the inside diameter plus the measured thickness, or the outside diameter minus that thickness. Grade 2 plate commonly carries a plus-side thickness tolerance, so the measured value can sit above nominal. If you cut the blank to a length computed from 10 mm, the finished inside or outside diameter shifts by that deviation at the longitudinal seam. Confirm the control diameter and the measured thickness against the drawing revision and the standard edition named in the purchase order.

Is the 1500 mm width the circumference, the course height, or the rolled width?

It is an ordered width, which is not necessarily the width the mill rolled, and the drawing decides how it is used. In a typical shell course the long dimension is cut to the developed length and rolled into the circumference, while the 1500 mm width becomes the axial course height. Nesting can rotate that by ninety degrees. A wider mother plate or coil may be slit or sheared to 1500 mm, so the delivered width carries a cutting tolerance, an edge camber and an edge condition. Confirm the mill-or-slit basis and which edge becomes the circumference before treating 1500 mm as a geometric input.

How much error does using the outside diameter instead of the mean diameter create?

It makes the blank longer than the true mean-diameter circumference by pi times t. Pi is about 3.14159, so on a 10 mm plate the surplus is about 31.4 mm, and the error grows with thickness. Using the inside diameter alone makes the blank short by the same amount. These are deterministic arithmetic results, not supplier tolerance figures. A blank that is too long forces trimming and re-bevelling at the longitudinal seam; a blank that is too short leaves a gap that cannot be pulled together without changing ovality. Compute L from the mean diameter and confirm it against a measured first-article circumference.

What happens at fit-up when the measured thickness is above the nominal 10 mm?

With a fixed blank length, a thicker plate gives a smaller inside diameter and a larger outside diameter than the nominal calculation predicts. If the drawing controls the inside diameter because internals, a lining or a volume must fit, the under-run inside diameter is the failure. If the course must match a standard head, a flange straight flange or an adjacent course on the outside, the over-run outside diameter drives hi-lo at the circumferential joint. The plus tolerance therefore travels from the thickness gauge into the diameter, then into the seam and the head interface. Re-measure the rolled course and re-check the control basis rather than accepting the nominal figure.

If a plate is substituted by a thicker band or a different width, must the blank be re-cut?

Yes. Any change of heat, thickness band, ordered width or coil-versus-plate form resets the measured thickness that feeds the development calculation. Re-run L equals pi times Dm with the new measured mean thickness, re-cut the blank, re-check the mill-or-slit width basis and re-issue the 14-line verification sheet before rolling. A substitute plate cut to the old blank length is a reject even if the mill certificate is clean. Keep the heat number tied to the new calculation and photograph identity before and after cutting.

Who signs off flatness and edge quality before the bevel is machined?

The machining supervisor signs the flatness and bevel-allowance check against the drawing clause, and the welding inspector signs the edge-quality, burr and heat-affected-zone check against the edge-preparation procedure and the joint detail. Flatness is not cosmetic: a wavy edge changes the stock height presented to the bevelling tool, so the bevel angle, root face and land drift along the joint. Published flatness figures disagree, so name the governing drawing clause and the standard edition, measure out-of-flat on a surface plate and confirm that enough machining allowance remains.

Is the fit-up dimension check the same as the receiving and weight-settlement check?

No. They are two independent check lines at two gates. The receiving line decides what the buyer pays, using the purchase order, the weighbridge ticket or area calculation and the certificate; the question of area versus weight settlement belongs there. The fit-up line decides whether the plate assembles, using the drawing revision, the measured mean thickness, the development calculation, the width and camber record, the bevel measurements and the signed verification sheet. A plate can be on weight and still fail fit-up, and a well-fitted course can still be disputed at the weighbridge. A pass on one does not grant a pass on the other.

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Why buyers come to us

Stock holder in Baoji Titanium Valley with ~800 t inventory · cut-to-size and small batch · drawing-based machining for non-standard parts · we read ASTM / ASME / GB specs · export experience · same-day response on quotes.