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The average torque recorded during the final few feet of installation.
Recorded from the installation rig's torque indicator or a calibrated torque monitoring device.
The empirical torque correlation factor for your specific shaft.
Kt is inversely related to shaft diameter and varies by manufacturer and shaft type (round vs. square) — use the specific value published for your product, not a generic assumption.
Estimated ultimate capacity
35 kips
Torque correlation is an empirical estimate, not a substitute for load testing on critical projects — it's most reliable when the site soil is reasonably uniform and the specific Kt factor has been validated for similar conditions.
- Equivalent in lbs
- 35,000 lb
They open the calculator with your figures already in it
Helical Screw Anchor Pull-Out Capacity Calculator: 35 kips — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
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How this was calculated
Formula source(s)
- Torque correlation method (widely used across the helical pile/anchor industry): ultimate capacity Pu = Kt x T, where Kt is an empirical torque factor specific to the shaft geometry and T is the final installation torque
Inputs used
- Final Installation Torque (ft-lb)
- 5000
- Torque Factor (Kt, per ft)
- 7
Intermediate steps
- Equivalent in lbs
- 35,000 lb
Confidence note: Torque correlation is an empirical estimate, not a substitute for load testing on critical projects — it's most reliable when the site soil is reasonably uniform and the specific Kt factor has been validated for similar conditions.
What this calculation does not cover
- This returns ultimate capacity, not a working load. No factor of safety is applied and nothing here compares the figure against the load on the pile — dividing ultimate capacity down to an allowable capacity is the engineer's step, not this calculator's.
- Torque correlation describes the soil, not the steel. The shaft's tensile strength, the coupling bolts, the helix plates, and buckling of the shaft in compression through soft or organic soil can all govern below the soil capacity returned here, and the smaller of the two controls the pile.
- There is no input for embedment depth, helix diameter or helix count. The correlation assumes the helices are deep enough below grade to fail in deep bearing; an anchor without adequate cover over the top helix fails by shallow cone breakout at less than this figure, which is exactly the direction a pull-out anchor is loaded in.
- The figure reflects only the soil the anchor was turning through over the last short stretch of installation. A weaker stratum above the helices, uncontrolled fill, a perched water table, seasonal moisture change, closely spaced anchors interacting as a group, and long-term creep under sustained tension in soft clay are all invisible to a torque reading.
- This is a field verification estimate, not a foundation design. It does not size the pile, check lateral or overturning loads, address frost depth, adfreeze or corrosion over the service life, and it does not replace the load testing and stamped engineering that permitting authorities generally require for helical foundations.
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This result is a specification — 35 kips — not a quantity. Put the thing it sizes into your project: how many, what you call it, and your supplier’s price.
Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.
Sources checked 2026-09-02 · in the site-wide review of 2026-09-06 · v1.0.1
Regulatory standards & verification citations1
- Torque correlation method (widely used across the helical pile/anchor industry): ultimate capacity Pu = Kt x T, where Kt is an empirical torque factor specific to the shaft geometry and T is the final installation torque
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