How to use the shot peening coverage checker
Enter the arc heights measured at an exposure time t and at double that time, and the page works out the rise and tells you whether peening has saturated. Below that, a single measured coverage point lets it back out the exponential constant and show the time to 98% coverage along with the 200% time.
Saturation is the first point at which doubling the exposure time raises the arc height by about 10% or less, and the arc height there is the Almen intensity. Coverage is modeled as one minus an exponential decay, fitted from the point you measured. The page follows SAE International shot peening practice, is current as of October 2026, and rests on secondary sources such as conference papers, so please check the standards themselves.
Unit conversions between Almen strip types, intensities for particular media and blast settings, and residual stress depth were not confirmed in an authoritative source, so no such value is offered here and only your readings are used. Abrasive consumption and blast cycle times are not covered. The result is for reference and does not replace process qualification. Review by a qualified engineer is required.
Frequently asked questions
Saturation is the first point where doubling the exposure time raises the arc height by about 10% or less. The arc height at that point is the Almen intensity. You can type a different rise if your procedure uses one.
No. Coverage of 98% is treated in practice as full coverage, and 200% means twice the time it took to reach that 98%. It is a multiple of exposure time rather than an area share, which is why the page spells it out next to the result.
Conversions between Almen strip types and measuring units were not confirmed in an authoritative source. The rise is a ratio of two readings in the same unit, so it does not depend on the unit; your unit is carried through to the Almen intensity line.