Does this worksheet select stud size, material class or preload?

No. Diameter, target preload and torque coefficient must come from the controlled joint design, assembly procedure and matching torque-clamp evidence.

Can one dry or lubricated nut factor be used for every joint?

No. Torque-preload behavior depends strongly on the exact threads, nut, washer or bearing surface, material, coating, lubricant, cleanliness, reuse, running torque and test method.

Does T=KDP establish ASME, ISO, ASTM or VDI compliance?

No. It is an empirical point relationship. Applicable standards and the approved assembly procedure control design, test, tightening sequence, tooling, scatter and acceptance.

Controlled empirical assembly worksheet

Documented stud torque from target preload

Apply one controlled torque coefficient K to one per-stud target preload P and the matching nominal diameter D. The worksheet performs the empirical arithmetic T = KDP; it does not select a stud, strength, preload, lubricant or assembly procedure.

No material presetsNo generic dry/lubricated KExact SI/imperial unitsNo compliance verdict

Critical boundary: torque is an indirect and friction-sensitive way to target clamp force. A point value of K cannot predict achieved preload or its distribution. Use only data and a procedure matching the exact fastener, nut, bearing surface, coating, lubricant, cleanliness, reuse/cycle condition and tool process.

1. Controlled empirical inputs

Documented torque coefficient K *

Dimensionless point value from the exact controlled configuration; not a generic lubricant label.

K evidence method *

Optional controlled lower K bound

Used only for arithmetic preload sensitivity at the nominal torque; it is not a confidence interval unless the source says so.

Optional controlled upper K bound

Matching nominal diameter D *

Diameter unit *

Controlled target preload P per stud *

Preload unit *

2. Joint, source and assembly record

Record / joint ID *

Exact stud, nut, washer and joint identities *

Drawing / specification revision *

Target-preload source, edition and location *

Per-stud load case and preload basis *

K test/report source, revision and sample statistics *

K configuration: threads, materials, coating, lubricant and surfaces *

Diameter definition used by the K source *

Rotating nut/end and bearing interface *

Assembly sequence, passes and running-torque treatment *

Tool ID, calibration date, range and accuracy *

Temperature, cleanliness, reuse/cycles and service condition *

Analyst / checker *

Record date *

Merknader

3. Confirmations

I verified that the target preload is a per-stud value from the controlled joint design and governing load/assembly procedure—not a generic percentage of a property-class value.I verified that K and any bounds match the exact threads, nut, washer/bearing surface, material, coating, lubricant, application quantity, cleanliness, reuse/cycles, temperature and running-torque treatment.I verified that D is the same nominal-diameter definition used by the K evidence and that the entered units refer to one tightened stud/nut interface.I will use the result only inside the approved procedure that controls preload scatter, tool calibration/range, tightening sequence/passes, gasket or joint behavior and verification; it is not an ISO/ASME/ASTM/VDI compliance verdict.

4. Empirical point result

Nominal torque-

Normalized target preload-

Method and applicability

T_nom = K × D × P_mål
If controlled K bounds are supplied and T_nom is applied: P_sens,low = T_nom/(K_høyD); P_sens,high = T_nom/(K_lowD)

What is calculated

One empirical nominal torque for one target preload.
Exact N, kN, lbf, mm, inch, N·m and lbf conversions.
Optional arithmetic K-bound preload sensitivity only.

What must be controlled

Target preload from the complete joint design.
Configuration-specific K evidence and statistics.
Assembly sequence, tool and verification procedure.

What is not calculated

Stud strength, stress area, yield/proof utilization or thread stripping.
Flange/gasket load distribution, relaxation, thermal or external loads.
Achieved-preload probability, acceptance or code compliance.

The optional sensitivity interval is not a guaranteed preload interval and not a statistical confidence/tolerance bound unless the controlled source explicitly defines it that way. A point K by itself provides no scatter estimate.

Sources and standards boundary

NASA Goddard — Torque Tension Testing of Fasteners Used for NASA Flight Hardware Applications: gives T = KDP, documents test determination of K, strong dependence on friction/lubrication/configuration and wide scatter; its reported coefficients are specific to tested hardware and are not presets here.
NASA RP-1228, Fastener Design Manual, March 1990, printed page 17: presents T = KFd as a quick empirical formula and explicitly warns that an assumed K = 0.2 must not be used blindly.
ISO 16047:2005 with Amendment 1:2012: published and confirmed torque/clamp-force test conditions for applicable fasteners; it is a test standard, not a universal K table.
ISO 898-1:2013 with Cor 1:2013: published mechanical-property scope for specified carbon/alloy-steel metric fasteners; its official scope explicitly excludes torque/clamp-force performance and points to ISO 16047 for testing.
ASME PCC-1—2022: current official scope is pressure-boundary flanged joints with specified ring-type gasket geometry—not every stud application and not a generic K value.
VDI 2230 Part 1:2015-11: controlled calculation method for highly stressed single-bolt joints; the licensed method is not reproduced by this point worksheet.
ASTM A193/A193M-26: active bolting-material specification for high-temperature/high-pressure and special-purpose applications. It does not justify one universal B7 preload or K value; exact material/design criteria remain controlled project inputs.
NIST SP 811 Appendix B: exact inch and pound-force basis used for unit normalization.

Klassifikasjon: T = KDP is an empirical general-engineering relationship, not an ISO torque formula. The former metric stress-area table, B7/L7/property-class strengths, 70–75% utilization presets, generic dry/oiled/MoS₂/anti-seize coefficients, universal ±25% statement and assembly advice are withheld as NEEDS_LICENSED_SOURCE or exact project-test/procedure data.