Architectural Flashing Supply
Start a Quote
Gauge thickness and material weights · Lesson 3 of 4

Gauge thickness and material weights: methods and worked application

An eight-step method from the order line to a recorded weight, worked examples with every input shown, and a micrometer check of delivered stock against its band.

You will be able to: Work from an order line to a documented decimal thickness and piece weight, record the units and the weight basis, and check delivered stock against a tolerance band.

9 min · 10 slides · 6 questions

All lessons in this module
Slide 1 of 10

A documented method

Work from order line to recorded weight in the same steps every time.

  • Read the order line: material, size and unit.
  • Name the table for that material.
  • Write the decimal thickness and its source.
  • Get the weight per square foot.
  • Girth times length gives the area.
  • Area times weight per square foot gives the piece weight.
  • Times the pieces; record units and basis.
  • Check the stock that arrives.
From order line to recorded weightProcess flow: read the order line, name the table, write the decimal thickness, ask whether a table weight exists, use it if yes or density times thickness times 144 if no, multiply girth by length for area, multiply by weight per square foot for piece weight, multiply by pieces and record units and basis, then check the stock with a micrometer. A dashed loop returns to naming the table when the reading is outside the band.Read the order lineName the tableWrite decimal thicknessTable weight?Use thetable weightDensity xthicknessx 144Girth x length = areaArea x weight per sq ft= piece weightx pieces; record unitsand weight basisCheck the stock witha micrometeryesnooutside the band: hold, report, re-checkTable weight first, density second.

Process flow: read the order line, name the table, write the decimal thickness, ask whether a table weight exists, use it if yes or density times thickness times 144 if no, multiply girth by length for area, multiply by weight per square foot for piece weight, multiply by pieces and record units and basis, then check the stock with a micrometer. A dashed loop, labelled hold, report and re-check, returns to naming the table when the reading is outside the band.

The method used in every worked example: table weight first, density second, then check the stock that arrives. The weight rule is the AFS material register's; the 144 is square inches per square foot.

Sources

Videos for this lesson

What this video shows: A tool supplier shows how to read an outside micrometer. Its description lists cleaning the faces, placing the part against the anvil and reading the measurement. Checked against its description only; it is not about sheet metal tolerances.

Video: How to Read a Micrometer by Travers Tool Co, on YouTube. Chosen from the video's published description.

Glossary

Girth
The flat width of a flashing profile once unfolded, hems included. AFS's widest girth is 48 in, and girth times length gives the area of sheet in a piece.
Weight basis
The pounds per square foot per inch of thickness behind a computed weight, such as 40.80 for steel in 1931 or 41.82 for the weights Steel Market Update lists. State it next to any weight you compute.
Piece weight
The weight of one cut piece: girth in feet times length in feet times the weight per square foot of the sheet it is cut from.
Tolerance band
The range from minimum to maximum thickness a sheet may measure and still match its order. For 24 gauge galvanized, Steel Market Update lists 0.0236 to 0.0316 in. The tolerance that governs a delivery is the one in the order or mill certificate.