Estimating torque by hand measures the force needed to rotate an object around the axis. Torque is a mechanical and engineering concept as it measures rotational force.
Torque is measured in newton meters (Nm). Also, foot-pounds are units for measuring torque.
There are many methods of estimating torque by hand, including finger and palm rules, and the use of hand tools such as torque wrenches, ratchet, and torque multipliers.
A torque wrench accurately measures the specific amount to apply to the torque fastener. While a torque multiplier, on the other hand, increases the torque output from a hand tool such as a ratchet or wrench.
Other hand tools include torque sticks, which are long flexible rods used together with a torque wrench. Torque screwdrivers are special screwdrivers that measure the amount of torque used in a screw.
Also, the torque handles are hand-held devices that enable a user to put in a specific amount of torque to a fastener.
Generally, to estimate a torque by hand, it is essential to consider factors such as size and type of fastener, material, and the amount of torque needed to tighten it correctly. Additionally, the type of tool used is essential, as different devices have different ratings and capabilities.
Contents
Is there a way to estimate torque by hand?
Yes. There are several methods to estimate torque by hand. The technique can be done using “finger” and “palm” rules. Torque by hand is calculated using a torque wrench, torque multiplier, and other hand tools.
However, using torque by hand is associated with errors and, thus, should be the last option in cases where accurate results are recommended, or hand tools such as torque multiplier and torque wrench are not available.
How to estimate torque by hand
There are many methods to estimate torque by hand, including tools such as torque screwdrivers, torque wrenches, torque sticks, and torque handles, in addition to techniques such as the finger rule and palm rule.
In the palm rule, you place your hand on the torque hand tool handle, say the wrench or multiplier, and close your fingers around the handle.
The force needed to rotate the handle in your palm will equal that needed to tighten the fastener. It is the most effective method when using tools with longer handles.
In the finger rule, you place your hand on the tool handle and close your fingers around it, similar to the palm rule. However, instead of using your palm to rotate the handle, you use your fingers to apply the force.
The force required to turn the handle using your fingers is equal to that needed to tighten the fastener. The method gives more accurate results as compared to the palm.
However, strong hand-eye coordination is necessary and is best for hand tools with smaller handles and when correct torque measurements are optional.
It is essential to be careful when using torque by hand as too much or less torque to the fastener could lead to problems such as loose connections.
Use of hand is not recommended due to inaccuracy; thus, torque wrench and torque multiplier are essential.
How much torque can a human apply by hand?
The units of torque that a human can apply by hand depend are several factors, such as the strength and size of the person, the type of fastener being tightened, and the length of the torque tool handle.
For instance, a healthy adult male could apply 90-100 Nm torque by hand at maximum. At the same time, a female could apply up to 60Nm torque.
The figures are not fixed, as it varies depending on the strength and the type of task. Also, a more extended handle hand tool would force the individual to use more torque than a shorter handle hand tool.
Furthermore, a person with stronger muscles applies more torque than weaker hand muscles.
Generally, the amount of torque applied depends on the type of fastener being tightened, as larger pins require more torque while smaller one needs less torque. There, the use of the hand in a critical application is discouraged.
Closing thoughts
Torque by hand is not recommended. The strength, length of the handle, and gender of the user play a significant role in determining the torque units, as males have proven to have more significant strengths than females.
Also, shorter-handle hand torques require less leverage than long-handled tools. A torque wrench and torque multipliers should be prioritized as they give accurate and more reliable results than the hands.
However, there are situations when torque measurements are not needed or when you cannot find a wrench and multiplier; torque by hand is thus used.
By use of the correct tools and procedures, there is the confidence to come up with the accurate torque needed to tighten a fastener, thus, ensuring the safety and reliability of a used product.
