Quick answer: A bobby pin is a closed pin that springs shut to clamp a few strands flat, which makes it best for flyaways, small sections and hidden support. A U-shaped hair pin is open and holds by tension inside a bun or twist, which makes it best for buns, chignons and French twists. Most updos use both.
Key takeaways
- Bobby pins clamp; U-pins hold by tension.
- Use bobby pins for flat, small sections and U-pins for volume.
- Bobby pins can flatten a bun; U-pins can slip out of a flat section.
- Fine hair often finds U-pins gentler because they do not pinch.
- The name bobby pin comes from the bob haircut that became popular in the early 20th century (Mental Floss, 2024).
The basic difference
The difference is in the shape. A bobby pin has two prongs pressed together, one straight and one wavy, with a tension that makes them spring shut. A U-shaped pin has two prongs that stay apart, shaped like a U or a narrow wave. One clamps, the other slides in and holds by friction.
| Bobby pin | U-shaped hair pin | |
|---|---|---|
| Shape | Closed; one straight and one wavy prong | Open U or wave |
| How it holds | Springs shut and clamps | Tension inside the hair |
| Best for | Flyaways, small sections, braids, hidden anchors | Buns, chignons, French twists |
| Effect on volume | Flattens what it holds | Keeps volume |
| On fine hair | Can pinch | Usually gentler |
| Visibility | Easy to hide | Plain pins hide; decorative pins show |
Where the name bobby pin comes from
Bobby pins are named after the bob hairstyle, which became hugely popular in the early 20th century. Women with newly short hair needed a small, discreet way to hold it in place, and the clips that did so became known as bobby pins. Mental Floss notes that several people have been credited with the invention, including San Francisco cosmetics businessman Luis Marcus (Mental Floss, updated October 15, 2024).
When to use bobby pins
Use bobby pins whenever you need to hold a small section flat or hide an anchor. They are the right tool for pinning back bangs, securing the end of a braid against the head, catching flyaways around an updo and anchoring a section under a claw clip or bun.
- Bangs and face-framing pieces: slide in from the side, wavy side down.
- Securing braids: pin the end of a crown braid flat.
- Flyaways: pin small pieces near the nape.
- Extra hold: cross two pins in an X under a heavy section.
Our Black Bobby Pins Card comes in wave or straight styles, 5 or 6 cm.
When to use U-shaped hair pins
Use U-pins whenever you are holding a bun or a twist with volume. They slide into the hair without flattening it and hold by tension, so buns stay round and French twists stay smooth. Larger U-pins can hold a small bun on their own.
- Buns and chignons: four to six around the edge.
- French twists: along the seam.
- Messy buns: loosely, for hold without stiffness.
- Events: decorative pins with pearls or leaves.
Plain options like our Black U-Shaped Hair Pins disappear into dark hair; Pearl U-Shaped Hair Pins decorate the style. Learn the technique in how to use U-shaped hair pins.
Quick decision guide
If you are unsure which pin to reach for, ask what the pin needs to do. If it must hold a small piece of hair flat and out of sight, use a bobby pin. If it must hold a rounded shape such as a bun or twist without crushing it, use a U-pin. If it must do both, use U-pins for the shape and bobby pins underneath.
| You want to… | Reach for |
|---|---|
| Pin back bangs or a side section | Bobby pin |
| Hold a bun or chignon | U-pins |
| Hide the end of a braid | Bobby pin |
| Hold a French twist seam | U-pins |
| Catch flyaways near the nape | Bobby pin |
| Add a decorative touch to an updo | Decorative U-pin |
How to insert a bobby pin correctly
Bobby pins hold best when the wavy prong faces your scalp, because the ridges grip the hair underneath. Slide the pin in against the direction the hair wants to fall, and push it until only a little shows.
- Hold the section where you want it.
- Open the pin slightly with a fingernail.
- Slide it in with the wavy side down, against the hair's fall.
- For more hold, add a second pin crossing the first in an X.
Using both in one updo
Most secure updos use U-pins for shape and bobby pins for support. For a low bun, for example, use U-pins around the bun to hold its shape, then a couple of bobby pins underneath to anchor any heavy or loose sections. For a French twist, U-pins along the seam and bobby pins at the bottom where the twist starts.
| Style | U-pins | Bobby pins |
|---|---|---|
| Low bun | Around the bun | Under heavy sections |
| French twist | Along the seam | At the base |
| Half-up | Optional | To flatten the section before a clip |
| Crown braid | Optional for volume | To secure the ends |
Which is better for fine or thick hair?
For fine hair, U-pins are often the better choice for buns because they do not pinch or flatten, and they need less hair to hold. Bobby pins are still useful for small sections. For thick hair, use more U-pins, larger ones, and add crossed bobby pins under heavy sections for extra anchoring. Our guide to pinning back bangs covers bobby pin techniques for the front.
Matching pins to your hair color
Plain pins work best when they disappear. Black pins blend into dark hair, while lighter hair may suit pins in a finish closer to its tone. Where a pin will show, choose it on purpose: a pearl U-pin or a decorative clip turns the hold into part of the look. Hide the working pins underneath and let one or two decorative pieces sit on top.
Care and storage
Pins are small and easy to lose. Keep them in a lidded tin or on a magnetic dish, put used pins back straight away, and throw out pins whose tips have lost their protective coating, since bare tips can scratch the scalp. Keep decorative pins separately so pearls and stones are not scratched.
Frequently asked questions
What is the difference between a bobby pin and a hair pin?
A bobby pin is closed and clamps a few strands flat. A U-shaped hair pin is open and holds buns and twists by tension.
Which side of a bobby pin goes down?
The wavy side usually goes toward the scalp, because the ridges grip the hair underneath.
Can I use bobby pins for a bun?
You can, but they may flatten it. U-pins usually hold a bun's shape better.
Why are they called bobby pins?
They are named after the bob haircut that became popular in the early 20th century (Mental Floss).
Are U-pins and French pins the same?
Yes, the terms are often used for the same open U-shaped pin.
How many bobby pins does a half-up style need?
Usually two crossed in an X are enough to hold the top section flat, plus one or two more for flyaways.
Shop pins
Find bobby pins, plain U-pins and decorative pins in our hair pins collection, and see how every clip type compares in Types of Hair Clips. Orders ship within the US for a flat $6.99, or free on orders of $79 or more.
Sources
- Jake Rossen, Why Do We Call Them Bobby Pins?, Mental Floss, updated October 15, 2024.
