What is 10 ft lb in inch pounds?

10 ft lb is a measurement of torque, specifically the amount of rotational force that can be generated by applying a force of 10 pounds on the end of a lever that is 1 foot long. In other words, 10 ft lb represents the torque or twisting force that can be produced by a 10 pound weight on the end of a 1 foot long wrench. To convert 10 ft lb to inch pounds, we need to understand the relationship between foot-pounds and inch-pounds when measuring torque.

The Relationship Between Foot-Pounds and Inch-Pounds

Foot-pounds and inch-pounds are both units used to measure torque, which is the rotational equivalent of linear force. Just as linear force is measured in pounds, torque is measured in pound-feet or pound-inches. A foot-pound represents the torque generated by a 1 pound force applied on a lever arm that is 1 foot long. Similarly, an inch-pound represents the torque generated by a 1 pound force on a 1 inch lever arm.

Since there are 12 inches in 1 foot, it follows that 1 foot-pound is equal to 12 inch-pounds. This conversion factor allows us to easily convert between foot-pounds and inch-pounds when dealing with torque measurements. The general relationship can be stated as:

1 foot-pound = 12 inch-pounds

Or conversely:

1 inch-pound = 1/12 foot-pounds

This fundamental relationship is key for converting 10 ft lb to inch pounds, as we will see shortly.

The Conversion Formula

Using the relationship between foot-pounds and inch-pounds, we can derive a simple formula for converting any torque measurement in foot-pounds to inch-pounds:

Inch-pounds = Foot-pounds x 12

So for our specific conversion, substituting 10 ft lb into the formula yields:

Inch-pounds = 10 ft lb x 12
= 120 inch-pounds

Therefore, 10 foot-pounds is equivalent to 120 inch-pounds. The conversion factor of 12 allows us to quickly convert the units and determine that 10 ft lb equals 120 inch lb.

Step-by-Step Conversion Process

To summarize the conversion process in step-by-step form:

1. Start with the original torque measurement of 10 ft lb

2. Identify the conversion relationship:
1 foot-pound = 12 inch-pounds

3. Use the formula:
Inch-pounds = Foot-pounds x 12

4. Plug in the original 10 ft lb measurement for foot-pounds

5. Multiply by 12 to convert to inch-pounds
10 ft lb x 12 = 120 inch-pounds

6. The result is 120 inch-pounds

So following these steps clearly shows that 10 ft lb converted to inch-pounds is equal to 120 inch-pounds.

Double Checking the Conversion

It’s always a good idea to double check unit conversions, especially when first learning the process. We can verify that our conversion is correct by working the process in reverse:

Starting with 120 inch-pounds
Applying the conversion factor of 1 ft lb = 12 in lb
Gives us 120 in lb / 12 = 10 ft lb

So converting 120 inch-pounds back to foot-pounds gives us the original 10 ft lb measurement. This helps confirm that the initial conversion from 10 ft lb to 120 inch-pounds is accurate.

Examples of Using 10 ft lb of Torque

To better understand the practical significance of 10 ft lb, here are some examples of situations where this amount of torque would be applied:

– Tightening lug nuts on a car tire to the proper torque specification. Lug nuts on most passenger car wheels are typically torqued to 70-100 ft lb.

– Tightening a 1/4″-20 hex bolt to a specification of 10 ft lb using a standard hex wrench.

– Holding up a 10 pound weight on a 1 foot long horizontal lever. The torque required at the fulcrum point to hold the weight in static equilibrium is 10 ft lb.

– Turning a rotary valve using a 1 foot long wrench that has 10 pounds of force applied at the handle.

– Lifting up one end of a 100 pound engine block using a 10 pound force on a 1 foot long pry bar.

So in practical terms, 10 ft lb represents a modest amount of torque that can be generated through hand tools and levers for applications like those shown above. It is a useful benchmark amount of torque for mechanical and engineering purposes.

Converting Other Torque Values

The same conversion process can be applied to convert any torque measurement between foot-pounds and inch-pounds:

– To convert foot-pounds to inch-pounds, multiply the foot-pounds value by 12
– To convert inch-pounds to foot-pounds, divide the inch-pounds value by 12

Some examples:

– 5 ft lb x 12 = 60 in lb
– 35 ft lb x 12 = 420 in lb
– 250 in lb / 12 = 20.8 ft lb
– 1800 in lb / 12 = 150 ft lb

So whether starting with inch-pounds or foot-pounds, you simply need to apply the ratio of 1 ft lb = 12 in lb to make the conversion. This proportionality relationship makes switching between the units quite straightforward.

Converting 10 ft lb to Other Torque Units

In some fields such as aviation, torque is measured using different units like the newton-meter (N-m). But the conversion process follows the same principals of proportionality and dimensional analysis:

– 1 ft lb = 1.3558 N-m

So to convert 10 ft lb to newton-meters:

10 ft lb x 1.3558 N-m/ft lb = 13.558 N-m

We can summarize other common torque unit conversions for 10 ft lb below:

Unit Conversion Factor 10 ft lb converted
inch-pounds 1 ft lb = 12 in lb 120 in lb
newton-meters 1 ft lb = 1.3558 Nm 13.558 Nm
dyne-centimeters 1 ft lb = 1382500 dyne cm 13,825,000 dyne cm
joules 1 ft lb = 1.3558 J 13.558 J

So by applying the appropriate conversion factors, 10 ft lb can be converted into several alternative torque units as shown above. The conversion process remains the same regardless of the specific units involved.

Converting Torque in the Opposite Direction

For completeness, we can also demonstrate converting torque measurements starting from other units back to foot-pounds:

– 250 in lb x 1 ft lb/12 in lb = 20.83 ft lb

– 15 N-m x 1 ft lb/1.3558 Nm = 11.07 ft lb

– 5,000 dyne cm x 1 ft lb/1382500 dyne cm = 0.0361 ft lb

– 10 J x 1 ft lb/1.3558 J = 7.38 ft lb

So converting torque measurements from other units to foot-pounds simply requires dividing by the appropriate conversion factor rather than multiplying. But in all cases, applying dimensional analysis and proportional reasoning allows torques to be converted between different unit systems.

Practical Examples of Torque Conversions

Being able to convert between units is useful for solving many real-world mechanical problems. Here are some examples:

– A car’s wheel lug nuts are tightened to 100 ft lb. What is the equivalent torque specification in newton-meters?
– Using the conversion factor: 100 ft lb x 1.3558 = 135.58 Nm

– A machinist needs to tighten a screw to 45 in lb. If using a wrench with a 2 ft handle, how much force must be applied?
– 45 in lb / (2 ft * 12 in/ft) = 1.875 pounds of force

– If a 0.5 m long wrench can safely apply 40 N of force, what is the maximum torque that can be generated?
– (0.5 m) x (40 N) = 20 Nm
– 20 Nm x (1 ft lb/1.3558 Nm) = 14.75 ft lb

Being able to move between units allows torque requirements to be converted into usable inputs for designing tools, selecting fasteners, or tightening to specifications. The ability to convert torque measurements is an indispensable tool for engineers, mechanics, and do-it-yourselfers alike.

Torque Conversion Tables

For frequent torque unit conversions, printed tables or online conversion calculators can be very helpful. By looking up known conversion factors, you can quickly find the equivalent torque measurements between inch-pounds, foot-pounds, newton-meters, or other units.

Consulting a complete torque conversion chart saves the effort of memorizing conversion factors or working through the arithmetic each time. Whether you need to convert motor torque, measure fastener tightness, or size tools for applying a given torque, having access to conversion tables and calculators can simplify the process.

Here are some helpful resources for quickly looking up conversions between different torque units:

– Machinery’s Handbook conversion tables
– Fastener torque specification tables
– Online torque unit calculators

Using these tools allows for efficient unit conversions and gets you the right torque measurement for your application.


In summary, converting 10 ft lb of torque into other units like inch-pounds or newton-meters is straightforward using dimensional analysis and the appropriate conversion factors. The key relationship to remember is:

1 foot-pound = 12 inch-pounds

Applying this proportionality and following a step-by-step conversion procedure allows 10 ft lb to be converted into 120 inch-pounds, 13.558 newton-meters, or any other desired torque units. The same process can be used bidirectionally to convert torque measurements into foot-pounds from other starting units. Having access to unit conversion tables and online calculators makes torque unit conversions quick and convenient. So whether you’re tightening lug nuts, sizing a wrench, or analyzing motors, converting between different torque units is an essential engineering skill.

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