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2.185
19.8
lb
1
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2.185
19.8
lb
1
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%
The SIMpull cable pull calculator is specialized for Southwire SIMpull THHN®/THWN-2® conductors, which feature a proprietary factory-applied lubricant that dramatically reduces the coefficient of friction compared to standard THHN wire. While standard THHN has a coefficient of friction of approximately 0.5 (dry) or 0.35 (with field-applied lubricant), SIMpull conductors achieve friction factors of 0.15 or lower, enabling longer pulls with fewer intermediate pull boxes.
The SIMpull technology was developed to address one of the most labor-intensive aspects of electrical installation — pulling conductors through conduit. Traditional cable pulling requires field-applied lubricant (which can drip, require cleanup, and may be incompatible with some cable types), careful pull speed management, and frequent rest stops to prevent overheating or overloading pull equipment. SIMpull's factory lubrication eliminates these concerns.
The friction factor of 0.15 means that SIMpull can achieve pulls 2-3 times longer than standard wire before hitting tension limits. A run that would normally require an intermediate pull box at 150 feet can be accomplished in one pull up to 300+ feet with SIMpull conductors. This translates directly to labor savings — fewer pull boxes means fewer terminations, less conduit fitting cost, and faster installation time.
Beyond tension, this calculator also checks for conduit fill compliance (NEC Chapter 9, 40% maximum for 3+ conductors) and the jam ratio. The jam ratio D_conduit/d_cable is critical for three-cable pulls — if 1.05 < D/d < 3.0, the three cables can wedge together at bends, making further pulling impossible. SIMpull's smooth surface helps cables slide past each other rather than jamming.
Enter the cable outside diameter (from manufacturer's data sheet), conduit inside diameter (from NEC Chapter 9, Table 4), pull length, cable weight per foot, number of cables, and the SIMpull friction factor (default 0.15, range 0.12-0.20 depending on conduit type and installation conditions).
Pull tension = µ × W/ft × L × N = SIMpull_factor × weight × length × num_cables (horizontal run, no bends). Conduit fill = N × π(d_cable/2)² / π(D_conduit/2)² × 100%. Jam ratio = D_conduit / d_cable. Jamming risk is flagged when jam ratio is between 1.05 and 3.0 for 3+ cables.
If jam ratio is between 1.05 and 3.0 with 3+ cables, consider using a larger conduit (jam ratio > 3.0) or smaller conduit (all cables touching — impossible to jam). SIMpull's lower friction factor significantly extends maximum pull length compared to conventional THHN. Fill must remain below 40% for NEC compliance.
Inputs
Results
Tension = 24.75 lb (SIMpull at µ=0.15) vs. 82.5 lb (standard at µ=0.5). Note: fill 47.1% exceeds 40% NEC limit and jam ratio 2.185 is in the jamming zone — upgrade to 1-1/4" conduit.
Inputs
Results
1-1/4" conduit: fill 27.2% (compliant), tension 29.7 lb over 300 ft. Jam ratio 2.875 is still in risk zone — approaching 3.0 limit. Use 1-1/2" conduit for jam-free installation.
SIMpull THHN/THWN-2 is a UL-listed conductor with a factory-applied proprietary lubricant that reduces pulling friction by up to 67% compared to standard THHN. It eliminates the need for field-applied pulling lubricant and enables longer, easier cable pulls.
Southwire rates SIMpull at a friction factor (µ) of approximately 0.15 in EMT and PVC conduit. Actual values range from 0.12 (PVC, smooth pull) to 0.20 (EMT with bends) depending on installation conditions.
No — the lubrication is permanently bonded to the cable jacket during manufacturing. It does not wash off, dry out, or require any field application. This also eliminates cleanup and lubricant disposal concerns.
Jam ratio = conduit inside diameter / cable outside diameter. For three cables, if 1.05 < jam ratio < 3.0, the cables can wedge together at bends, making further pulling impossible without damaging the cables. Use a conduit where jam ratio > 3.0 or < 1.05 to avoid jamming.
Yes — SIMpull THWN-2 is rated for wet locations (submersible to THWN-2 standards) and temperatures up to 90°C. It is suitable for conduit in wet locations, direct burial conduit systems, and standard dry indoor installations.
SIMpull conductors have the same outside diameter as standard THHN/THWN-2, so NEC Chapter 9 conduit fill calculations are identical. SIMpull's lubrication affects only the pulling friction, not the physical dimensions of the cable.
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