What Is A 3-Prong Plug Called? | Plug Naming Guide

Ask ten people what that familiar three-pin household plug is called and you’ll hear a mix of answers. Some say “grounded plug.” Others say “Type B.” Electricians may toss out a code like 5-15P. All three can be right, depending on where you live and what you’re holding. This guide clears up the names, the codes behind them, and details that help you match plug, outlet, and cord.

We’ll start with the everyday North American answer, then branch out to regional names and the computer-style connectors many people lump into the same bucket. You’ll pick up quick ID tips, safety notes, and a simple way to read NEMA numbers on the plug. That way, picking the right cord takes seconds, not guesses.

The Common Name People Mean

In the United States, Canada, parts of Mexico, and Japan, the classic three-prong household plug is the Type B design. In trade language it usually carries the code NEMA 5-15P for a 15-amp, 125-volt plug with two flat blades and one round grounding pin. If your lamp, fan, or phone charger has three pins in this shape, that’s the name you want.

There are close cousins. A 20-amp version keeps the same three pins but the neutral blade has a sideways “T” shape; that one is coded NEMA 5-20P. Both mate with matching outlets labeled 5-15R or 5-20R, and both fall under the broader “Type B” family seen on travel charts.

Quick Map Of Common Three-Pin Names

Why Three Prongs Exist

Two blades carry the current: one “hot” and one “neutral.” The round pin bonds the appliance body to ground so a fault trips a breaker instead of shocking you. On many plugs the neutral blade is wider than the hot blade; that shape is called a polarized plug and it ensures the hot conductor lands on the correct side of the device.

Never remove or bend off the round pin to make a plug fit. That defeats the safety path. If you must use an adapter, pick one that keeps the ground connection intact.

For plain-language safety points, see the U.S. Consumer Product Safety Commission’s bulletin on cords and power strips; it backs the advice to use polarized or grounded plugs that match your outlet. The bulletin is posted here: CPSC guidance.

How NEMA Codes Work

On straight-blade household gear, the first number points to the voltage class, the second to the current rating, and the trailing letter tags the piece as a plug (P) or receptacle (R). So 5-15P means 125-volt class, 15 amps, plug. A dryer or range uses different families, such as NEMA 14-30 or 14-50.

Look closely at the body of the plug or its molded strain relief. Manufacturers usually stamp the full code there. If a device ships worldwide, you might also see an IEC appliance inlet on the product and a country-specific wall plug on the cord set that feeds it. The naming system itself lives with the trade group NEMA; you can learn the basics on the NEMA standards page.

Regional Three-Pin Variants

Plugs with three pins aren’t identical across the globe. The UK and Ireland use a rectangular pin design with a fuse inside the plug body; that design pairs with switched, shuttered outlets. Australia and New Zealand use slanted flat pins with a ground blade; related versions appear in China and Argentina. India and South Africa keep round pins in several sizes. Names on travel charts read Type G, Type I, Type D, and Type M for these families.

These shapes are not cross-compatible with North American Type B outlets. Travelers use a small adapter to match prong shapes. That adapter doesn’t change voltage by itself; a separate converter is needed for appliances that can’t accept local mains voltage. For UK gear, the governing spec is BS 1363, which defines the fused plug and the matching socket system used across the UK and Ireland.

When People Say “Computer Plug”

Many folks point at the cord feeding a desktop PC and call it a three-prong plug. One end does have three socket holes, but that end is an IEC 60320 C13 connector, not a wall plug. It mates with a C14 inlet on the computer’s power supply. The other end of that cord set is where the wall plug lives, and in North America that end will usually be NEMA 5-15P.

This naming split matters because IEC letters describe the appliance side only, while NEMA codes describe the wall side. Knowing both terms makes shopping and replacement easier.

Is A 3-Prong Outlet Plug Called Type B?

Yes. If you’re in North America or Japan and the plug has two parallel blades plus a round pin, Type B is the everyday label and NEMA 5-15P or 5-20P is the matching code. That’s the terminology you’ll see in product specs, breaker panel schedules, and outlet labels.

What A 3 Prong Electrical Plug Is Called Abroad

Across the UK and Ireland it’s a BS 1363 plug. In Australia and New Zealand it’s an AS/NZS 3112 plug, commonly grouped under Type I. In India a small three-pin plug is Type D, while large three-pin equipment often lands under Type M. Each system has its own outlet shape, current ratings, and fuse or no-fuse rules.

Identify Yours In Seconds

Start with the shape. Two flat blades and a round pin point to Type B. Slanted blades with a ground blade point to Type I. Three rectangular pins in a wide triangle point to the UK system.

Next, look for a code molded into the plug body. NEMA 5-15P and 5-20P are common on 120-V gear. BS 1363 appears on UK plugs. IEC C13 or C15 marks appear on the appliance end of many cord sets.

Then check the outlet. A T-shaped neutral slot marks a 20-amp 5-20R receptacle. A simple parallel slot next to a round hole marks a 15-amp 5-15R. UK outlets have shutters and a switch. Australian outlets set the slots at an angle.

If the code is missing or scuffed away, snap a clear photo of the plug face and ask a local hardware counter; staff can match shapes to the right code quickly.

Do’s And Don’ts For Three-Pin Plugs

• Keep the ground pin intact. If it breaks, replace the cord set.
• Match plug and outlet ratings. A 20-amp plug belongs on a 20-amp circuit.
• Use polarized or grounded extension cords that match the plug style.
• Avoid three-to-two adapters that drop the ground path.
• On UK plugs, fit the correct fuse value for the appliance.
• Route cords so they don’t pinch under furniture or doors.

Adapters, Converters, And Travel Gear

A small travel adapter changes the prong shape only. It doesn’t change local voltage or frequency. Many phone and laptop chargers accept 100–240 V; check the label. Heat-producing gear like hair dryers often needs a true converter or a country-specific model.

For desktop equipment, you can swap the wall end of an IEC cord set to match the destination. Keep the C13 or C15 end that fits your device, then choose a country-appropriate wall plug on the other end.

NEMA 5 Family Cheat Sheet

Glossary For Quick Reading

• Grounded: A third conductor that ties the appliance frame to earth.
• Polarized: Different blade widths so hot and neutral can’t swap.
• Double-insulated: Extra internal insulation; no ground pin present.
• Receptacle: The outlet on the wall; labeled with an R in NEMA codes.
• Plug: The part on the cord; labeled with a P in NEMA codes.
• IEC 60320: The appliance-side connector family like C13/C14.

Quick Picks For Everyday Scenarios

• Your new toaster has a three-pin plug and your outlet has a T-slot: you’re on a 20-amp branch.
• Your desktop PC cord has a C13 end and a North American wall plug: replace the wall end with the correct country plug when you travel.
• You moved from the UK to Canada: replace BS 1363 cords with NEMA 5-15P cords rated for the device; don’t chop pins to “make it fit.”
• Your workshop tool came with a two-pin plug: look for a model with a ground pin or one marked double-insulated.

Naming It Right Saves Time

When someone asks what a three-prong plug is called, answer with the name that fits the plug and the region. In North America, say “Type B” or “NEMA 5-15P.” In the UK, say “BS 1363.” For the computer cord, say “IEC C13 to NEMA 5-15P,” or swap in the wall plug that applies. Clear names speed shopping, prevent mismatches, and keep safety features working. That naming clarity saves time, money, and needless returns later.

What It Isn’t

A Schuko plug found in parts of Europe has two round pins and spring clips on the sides for earthing. That design gives a ground path but not a third pin. Travel charts label it Type F. People sometimes call it a three-prong style because outlets have two round holes plus contact strips, yet the plug itself carries only two pins.

Another source of mix-ups is the small figure-8 cord used on radios and tiny speakers. That cord has no ground path and no third conductor; its matching device inlet is labeled IEC C7 or C8. If a product requires grounding you’ll see three conductors or a metal ground pin on the connector.

Reading Packaging And Product Pages

Retailers often post the NEMA code in the specs. Look for 5-15P on cords for lamps, chargers, and small appliances. You might see 1-15P on older two-pin cords. Heavy kitchen tools and shop gear may list 5-20P. If the listing says “Type B,” that’s the same family and will fit any 5-15R outlet. When you shop UK gear, the spec sheet will call out BS 1363 and a fuse value.

For computers and displays, product pages list the IEC number for the appliance inlet and the wall plug for the region. A line like “C13 to 5-15P” tells you the appliance end and the wall end in one breath.

Troubleshooting Mismatches

If a plug won’t seat, pause and check both sides. A 20-amp plug won’t go into a 15-amp receptacle. A UK plug won’t enter a North American outlet. If an IEC C15 connector won’t fit your computer, look at the shape; a C15 has a notch that blocks a C13 inlet rated for lower temperatures.

When a cord runs warm, verify the rating. Long runs and thin wire raise heat. Pick a cord with a thicker gauge for high loads on 120-V circuits, and keep extensions as short as the setup allows.

Care And Replacement

Inspect plugs for cracked bodies, bent blades, or a missing ground pin. Replace worn parts instead of taping them up. On UK plugs, open the cover and check the fuse rating when you move a cord to a new device; match it to the appliance nameplate. On IEC cord sets, make sure the connector latches cleanly into the inlet and doesn’t wiggle loose.

Store cords loosely coiled. Tight wraps near the strain relief shorten life. Keep cords dry and out of footpaths, and hang them by the body, not the cable.