What Righty Tighty Lefty Loosey Means (Plus How to Implement It)

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Plus, how to tell which way is right & left on a rotating part

Co-authored by Perryn Olson and Elaine Heredia, BA

Last Updated: January 15, 2025 Fact Checked

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Meaning

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How to Implement It

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When to Switch Directions

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Phrase Origins

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FAQs

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Video

Has someone ever told you, "Righty tighty lefty loosey" while you're tightening or loosening something? This mnemonic phrase was invented to help mechanics and plumbers remember which way to turn a threaded part (like a screw or a bolt) to tighten or loosen it. If you're having trouble visualizing what turning a rotating part right or left should look like, this article will help you understand the meaning, usefulness, and history of "righty tighty lefty loosey."

Righty Tighty Lefty Loosey Explained

"Righty tighty lefty loosey" is a mnemonic for helping people remember which way to turn a screw and other threaded parts to tighten or loosen them on their fittings. Looking at the top of a screw, visualize turning it right (clockwise) to tighten it or turning it left (counterclockwise) to loosen it.

Section 1 of 5:

What does righty tighty lefty loosey mean?

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"Righty tighty left loosey" explains how to tighten or loosen a threaded part. For example, if you want to tighten a screw, you would rotate the screw to the right. If you want to loosen it, you would rotate it to the left. This is because most threaded parts – including screws, nuts, bolts, and connectors – have threads that slant upward to the right when you orient them with the top pointing up.
- Examples of common household items that use threaded parts include light bulb sockets, garden hoses, cabinet door knobs, furniture screws, and water supply valves.

Section 2 of 5:

How to Implement Righty Tighty Lefty Loosey

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Focus on the top of the threaded part and imagine moving it right or left. Keep its starting position in mind as you rotate it right to tighten or left to loosen. Avoid focusing on the bottom of the part or you're more likely to become confused.
- Some people look at the bottom of the head of a threaded part while they're rotating the head to the right to tighten it, and they think that because the bottom is technically moving in a leftward direction, that means they're actually turning the entire part to the left instead of the right. If you struggle with visualizing "right" and "left" on a rotating head, it may be helpful to frame the idea in a different context, like a clock face.
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Turn the threaded part clockwise or counterclockwise. Rotating a threaded part is similar to the hands on a clock rotating around the center of the clock face, so this is often an easier way for people to understand the concept of "righty tighty lefty loosey." Instead of thinking in terms of "right" and "left," turn the head of the threaded part clockwise (right) to tighten it or counterclockwise (left) to loosen it.
- Another way to remember that turning the part clockwise will tighten it is to say the phrase, "Time is always tight." The hands on a clock – i.e., time – move to the right around the clock face. So to tighten something, you must move it with the hands of the clock – i.e., the passage of time.

Section 3 of 5:

When to Switch Directions

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Change direction when dealing with left-handed threads. Go by "lefty tighty, righty loosey" for left-handed or reverse threads. If a thread is left-handed, it means the threads on a part slope upward to the left instead of to the right. Left-handed threads are used in some automotive parts, gas tanks, and other applications where external vibrations or rotations might cause right-handed threads to loosen on their own. If you meet unexpected resistance when turning to the right, it's a sign the thread is left-handed. Common examples of parts with left-handed threads include:^{[1]
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- Steering wheel bolts
- Lug nuts on some vehicles
- Specific types of hoses and machinery
- Propane tank connections
- Some vacuum extractor components
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Use "lefty tighty, righty loosey" when dealing with damage or rust. When you're working with a rusted or damaged part, "righty tighty, lefty loosey" may work, or it may not. If it doesn't, first try gently turning the part in each direction to determine which direction offers the least resistance. Then, apply a penetrating oil and let the part soak for a bit before carefully but firmly trying to loosen it again.

Section 4 of 5:

Origins of Righty Tighty Lefty Loosey

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One reason they're more common than left-handed threads is approximately 90% of the human race is right-handed instead of left-handed.^{[2]
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Research source} Another reason is that in 1864, engineer and machine tool builder William Sellers created standards for manufacturing threaded parts of different diameters (including making most of them right-handed) which we still use in the United States today.^{[3]
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Research source}.
However, many sources report that mechanics and plumbers have been saying it for at least a century – and maybe longer. Its rhyming scheme makes it easy to remember, although some people find using the terms "clockwise" for tightening and "counterclockwise" for loosening easier to understand.

Section 5 of 5:

Frequently Asked Questions (FAQs)

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Some parts have left-handed threads to prevent them from coming loose due to vibrations or external rotational forces. For example, the lug nuts on the wheels on the left side of the vehicle have left-handed, or reverse, threads to prevent the torque from the rotating wheels from loosening them while the vehicle is moving.
Yes, plumbing parts have right-handed threads and will tighten when you rotate them to the right (clockwise). Consequently, they will loosen when you turn them to the left (counterclockwise).
There is no one known inventor of the phrase "righty tighty lefty loosey," but mechanics and plumbers have been using it for decades.