Basic Torque Calculations - accu-calibration.com

Therefore, a longer lever will require less hand force to produce the same amount of torque.

T1 = F1 x L1 = 10 lbs x 2 ft = 20 ft·lbs

T2 = F2 x L2 = 20 lbs x 1 ft = 20 ft·lbs

T1 = T2

Use of Adapter

Formula:

TA x L
L + A

= TW

Length
(L) =

Effective length of the wrench as
described below.

Dial
Wrenches =

The measured distance from the center
of the square drive to the center ring or notch on the handle.

Micrometer
Wrenches =

The measured length from the center
of the square drive to the center of the handle, with the wrench set at the
desired torque reading.

Desired
Torque (TA) =

The torque value designated for the
fastener with or without an adapter.

Added
Length of Adapter (A) =

The measured length from the center
of the adapter drive to the center of the wrench square drive.

New
Setting (TW) =

The torque setting on the wrench
allowing for the added length of the adapter. This reading will be lower than
the desired torque.

Example:

250 ft. lb. Dial Wrench using a 2”
long crowfoot adapter

L = Effective Length: 18.75”

Desired Torque = 250 ft. lb.

Length of Adapter = 2”

Result:

18.75″ x 250 ft. lb.

18.75″ + 2″

= Pull Wrench to
226 ft. lb.

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