Xem Studiomeasured geometryLibrary › Tri-clamp & pipe › Conduit knockout diameters (NEMA Bulletin 71): 1/2 to 6 in trade…
knockout-gauge-2-1-2-to-4in
knockout hole gauge plate, 429.4 × 133.9 × 3 mm, 4 through holes at the NEMA Bulletin 71 nominal knockout diameters for the 2-1/2 to 4 in trade sizes (75.413, 91.288, 104.775, 117.881 mm), smallest first, 8 mm between hole edges; plate thickness, spacing and corner radius are Xem choices
Exact dimensions. True size, no tolerance added. Threads are plain cylinders at the major diameter.
STEP STL free, CC BY 4.0 (credit "Xem Studio")
Dimensions
| trade size (in) | 2-1/2 |
|---|---|
| metric designator | 63 |
| knockout min (in) | 2.938 |
| knockout nominal (in) | 2.969 |
| knockout max (in) | 3.000 |
| knockout min / nominal / max (mm, as printed) | 74.63 / 75.41 / 76.20 |
| metallic bushing flange Ø B (in) | 3.20 |
| nonmetallic locknut covering Ø B (in) | 3.156 |
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Conduit knockout diameters (NEMA Bulletin 71): 1/2 to 6 in trade sizes, minimum, nominal and maximum, with bushing and locknut diameters + hole gauge plates: every size, notes, mating features and sources. What size hole is a 1/2 inch or 3/4 inch conduit knockout, and how big are 1-1/4, 1-1/2 and 2 inch knockouts?