Common context
Common project roles are project-specific and may include specialty beams, industrial framing, existing-condition matches, and members selected for unusual proportions.
16 AISC v16.0 records
AISC Miscellaneous beams (M).
An M-shape is a miscellaneous doubly symmetric section that does not fit the standard W or S series proportions. The exact AISC record—not the nominal depth alone—defines its geometry and properties.
Detailing watch
Verify exact designation, availability, flange geometry, gage, connection compatibility, and substitution criteria before detailing or procurement.
Use the directory as a reference
How to read the M records
M is a separate miscellaneous beam series. Use the exact designation and dimensions; a matching nominal depth in another family is insufficient for a geometry match.
Record web and flange dimensions alongside weight, and confirm the specified section is available before procurement.
This dataset contains 16 M records, with nominal weights from 2.9 to 18.9 lb/ft and listed depth values from 3 to 12.5 in. These ranges describe the published records, not current supplier inventory or a selection recommendation.
Start with the exact designation, open its full record, then compare only the dimensions and properties relevant to your task. For example, M8X6.5 lists 6.5 lb/ft, 1.92 in² area, Ix = 18.5 in⁴ and Iy = 0.376 in⁴. The x and y labels retain the database axes; their values do not establish allowable loads.
The AISC v16.0 workbook Readme defines the variables and shape figures. This directory uses the US customary record; the comparison tool converts displayed units. Check the required edition and product specification before transferring data.
Worked quantity example
Nominal weight for M8X6.5
Assume 3 pieces, each 20 ft (6.096 m) long. This is a hypothetical quantity example, not a stock-length or lifting recommendation.
| Quantity | Calculation | Nominal pounds | Kilogram equivalent |
|---|---|---|---|
| One 20 ft piece | 20 ft × 6.5 lb/ft | 130 lb | 58.967 kg |
| 3 pieces | 3 × 130 lb | 390 lb | 176.901 kg |
Conversion: 1 lb = 0.45359237 kg; displayed results are rounded. This multiplication excludes connection plates, bolts, weld metal, coatings, cutting allowances and actual material variation. Use the material takeoff for your own lengths and quantities.
Crawlable designation index
All M shape records.
Showing all 16 records.
| Designation | Weight | Depth / OD / d | Area | X-axis Sx |
|---|---|---|---|---|
| M12.5X12.4 | 12.4 lb/ft | 12.5 in | 3.63 in² | 14.2 in³ |
| M12.5X11.6 | 11.6 lb/ft | 12.5 in | 3.4 in² | 12.8 in³ |
| M12X11.8 | 11.8 lb/ft | 12 in | 3.47 in² | 12 in³ |
| M12X10.8 | 10.8 lb/ft | 12 in | 3.18 in² | 11.1 in³ |
| M12X10 | 10 lb/ft | 12 in | 2.95 in² | 10.3 in³ |
| M10X9 | 9 lb/ft | 10 in | 2.65 in² | 7.79 in³ |
| M10X8 | 8 lb/ft | 9.95 in | 2.37 in² | 6.95 in³ |
| M10X7.5 | 7.5 lb/ft | 9.99 in | 2.22 in² | 6.6 in³ |
| M8X6.5 | 6.5 lb/ft | 8 in | 1.92 in² | 4.63 in³ |
| M8X6.2 | 6.2 lb/ft | 8 in | 1.82 in² | 4.39 in³ |
| M6X4.4 | 4.4 lb/ft | 6 in | 1.29 in² | 2.41 in³ |
| M6X3.7 | 3.7 lb/ft | 5.92 in | 1.09 in² | 2.01 in³ |
| M5X18.9 | 18.9 lb/ft | 5 in | 5.56 in² | 9.67 in³ |
| M4X6 | 6 lb/ft | 3.8 in | 1.75 in² | 2.48 in³ |
| M4X4.08 | 4.08 lb/ft | 4 in | 1.27 in² | 1.77 in³ |
| M3X2.9 | 2.9 lb/ft | 3 in | 0.914 in² | 1 in³ |
Values are derived from the AISC Shapes Database v16.0 in US customary units. Open a designation for its full property table, nominal profile, downloads, source notes, and limitations.