Cable Bend Radius Minimum
Minimum inside bend radius as a multiple of cable OD per manufacturer bulletins.
Example
You enter
- Cable type THHN
- Cable OD (in) 0.5
You get
- Multiple 4x OD
- Minimum inside bend radius 2 in
Checked against published worked examples from: Southwire.
Details, formula, and sources
Formula or tableMin bend radius = multiplier × cable OD; multipliers per cable type (THHN/XHHW 4x to 1 in OD, 5x to 2 in, 6x above; MC 7x, control 6x, coax 10x, fiber 20x).
Source and editionManufacturer minimums (Southwire 1000 V and below table, AFC, Belden, Corning); NEC 300.34 (8D/12D) applies only over 1000 V and is not the basis here.
Free accessFree read-only access at nfpa.org/freeaccess. Manufacturer guides free at each manufacturer site.
What governsEstimate. AHJ and licensed electrician govern. Verify against the NEC edition adopted in your jurisdiction.
API field namescable_type, cable_od_in, multiple, min_radius_in
- Multiplier table data/electrical/cable-bend-radius.jsonmanufacturer-attributed per row