Why require two measured anchors?

Published rules of thumb cannot capture the combined effect of the actual media, substrate, pressure, angle, distance, and technique. The fixed secondary assumptions are listed on this page and in the downloadable workbook so the four-input result remains auditable.

What happens outside the range?

The estimate is clamped to the nearest anchor and a warning is raised. The calculator does not invent an extrapolated profile. The fixed secondary assumptions are listed on this page and in the downloadable workbook so the four-input result remains auditable.

Does an in-window estimate guarantee acceptance?

No. Variation and measurement uncertainty can still produce out-of-window readings; production inspection remains required. The fixed secondary assumptions are listed on this page and in the downloadable workbook so the four-input result remains auditable.

Can I use nominal mesh size?

Only if both calibration anchors and the selected media use a comparable, documented size measure. The fixed secondary assumptions are listed on this page and in the downloadable workbook so the four-input result remains auditable.

Why are the two calibration points not editable?

They are the declared reference basis for this streamlined calculator, not routine job controls. Exposing them alongside the job fields made the page look like a curve-fitting tool. If your operation has different validated calibration points, use the workbook method as a starting specification and create a controlled site calibration before relying on the estimate.

What does process sigma add to the answer?

The estimated profile alone describes a center, not consistency. Sigma represents observed spread and lets the calculator compare normal process movement with the nearest specification limit. Use repeated readings from stable, comparable conditions; a guessed sigma can create false confidence even when the interpolated midpoint appears ideal.

Abrasive Blasting, Shot Peening & Surface Prep calculator

Calibrated Abrasive Blast Surface Profile Estimate

Screen an abrasive size against a required surface-profile window using selected media size, minimum profile, maximum profile and observed process sigma. The calculator interpolates from a documented two-point calibration and reports estimated profile, distance to each limit and a variation-aware capability margin. It is intentionally a planning aid rather than a universal media chart: alloy, hardness, shape, velocity, angle and substrate condition all influence the actual anchor pattern. Keeping the calibration fixed leaves four clear job decisions on the page, while the reference values and their limits remain visible in the methodology and workbook.

What this calculator does

Interpolate surface profile only between two measured shop calibration anchors and compare the estimate with the coating target window.
Use it for trial-blast planning, media-size selection, coating-window capability review, choosing a trial media size before producing qualification panels..
Interpolate surface profile only between two measured shop calibration anchors and compare the estimate with the coating target window.

Formula used

Estimated profile is interpolated from a fixed two-point site calibration, then compared with the target window and process variation.
Fixed secondary assumptions compiled into this release: Low calibration media size: 12 mil; Low calibration measured profile: 1.5 mils; High calibration media size: 30 mil; High calibration measured profile: 3.5 mils.

Inputs explained

Selected media size measure: Comparable particle-size measure for the planned media.
Target profile minimum: Minimum permitted coating anchor profile.
Target profile maximum: Maximum permitted coating anchor profile.
Observed profile standard deviation: Within-condition profile standard deviation from repeated measurements.

How to use the result

Best suited to trial-blast planning, media-size selection, coating-window capability review, choosing a trial media size before producing qualification panels..
The four-input result is conditional on the disclosed fixed assumptions; use a detailed engineering model when they are not representative. No extrapolation beyond measured anchors. Not a substitute for surface-profile inspection. Not transferable across substrate, media shape, pressure, angle, distance, or operator without validation. Linear interpolation cannot capture changes in media shape, hardness, velocity, impact angle or substrate response.

Common questions

Why require two measured anchors? Published rules of thumb cannot capture the combined effect of the actual media, substrate, pressure, angle, distance, and technique. The fixed secondary assumptions are listed on this page and in the downloadable workbook so the four-input result remains auditable.
What happens outside the range? The estimate is clamped to the nearest anchor and a warning is raised. The calculator does not invent an extrapolated profile. The fixed secondary assumptions are listed on this page and in the downloadable workbook so the four-input result remains auditable.
Does an in-window estimate guarantee acceptance? No. Variation and measurement uncertainty can still produce out-of-window readings; production inspection remains required. The fixed secondary assumptions are listed on this page and in the downloadable workbook so the four-input result remains auditable.
Can I use nominal mesh size? Only if both calibration anchors and the selected media use a comparable, documented size measure. The fixed secondary assumptions are listed on this page and in the downloadable workbook so the four-input result remains auditable.
Why are the two calibration points not editable? They are the declared reference basis for this streamlined calculator, not routine job controls. Exposing them alongside the job fields made the page look like a curve-fitting tool. If your operation has different validated calibration points, use the workbook method as a starting specification and create a controlled site calibration before relying on the estimate.

Last reviewed 2026-08-24.