Magnet Wire 30ga (800ft) mw30-4 | K&J Magnetics

Happy Holidays! Orders placed after 1:00PM EST on Tuesday, 12/23/2025, will be shipped on Friday, 12/26/2025.

Magnet Accessories
Other Products

Disc Magnets

All disc magnets and cylinder magnets. Axial and diametric magnetization options.

Cylinder & Rod Magnets

Round magnets with thickness greater than or equal to diameter. Cylinder magnets can be magnetized axially through thickness or diametrically.

Ring Magnets

Disc magnets with a hole are called ring magnets. See all round magnets with holes.

Pot/Cup Disc Magnets

Pot and cup magnets are circular shaped mounting magnets with countersunk and counterbored holes.

Studded & Threaded Disc Magnets

Disc magnets with male studs, female studs and internal threads.

Plastic Coated Disc Magnets

Waterproof plastic coated disc magnets to prevent rust and corrosion due to water and moisture.

Rubber Coated Disc Magnets

Rubber coated discs for high-friction and strong grip as well as waterproof protection against rust and corrosion.

Diametric Disc & Cylinder Magnets

Magnets that are magnetized through diameter.

Stepped Disc Magnets

Stepped disc magnets have slots or grooves for secure attachment and easy install. Great for embedding into parts.

Sewing Magnets

Disc sewing magnets are made to be sewn into clothing and curtains and some feature a plastic cover that can go through the wash.

Adhesive Disc Magnets

Magnets with strong 3M adhesive backing for easy attachment without screws and other hardware.

Epoxy Coated Disc Magnets

Magnets with epoxy coating that provides extra water and moisture resistance.

Countersunk Disc Magnets

Magnets with a hole for a screw that is angled so the screw will be flush with the top of the magnet.

Block Magnets

Block, square, rectangular and brick magnets. This category includes all block shapes.

Cube Magnets

Magnets in a cube shape with all equal dimensions.

Bar Magnets

Magnets in a bar shape that are magnetized through length like traditional north/south magnets or through width or thickness.

Adhesive Block Magnets

Magnets with a strong 3M adhesive backing for installation with no screws or hardware.

Countersunk Block Magnets

Countersunk block magnets have screw holes to attach to many surfaces for easy hanging with magnets.

Plastic Coated Block Magnets

Waterproof plastic coated block magnets to prevent rust and corrosion due to water and moisture.

Rubber Coated Block Magnets

Rubber coated blocks for high-friction and strong grip as well as waterproof protection against rust and corrosion.

Stepped Block Magnets

Stepped block magnets have slots or grooves for secure attachment and easy install. Great for embedding into parts.

Channel Magnets

Channel magnets are strong heavy-duty magnets best for lifting and hanging, etc.

All Neodymium Mounting Magnets

Browse all neodymium mounting magnets. All feature a heavy-duty stainless steel assembly that increase pull force to stainless steel and other ferrous metal.

Countersunk Pot/Cup Magnets

Cup and pot magnets in a ring shape with a countersunk or counterbored hole for easy installation and attachment.

Studded & Threaded Magnets

Male stud, female stud and internal thread magnets for easy install with screws and bolts for firm attachment.

Channel Magnets

Channel magnets are best for a strong heavy-duty hold, lifting and pulling.

Rubber Coated Mounting Magnets

Rubber coated mounting magnets offer the strength of a mounting magnet with a strong anti-slip grip and waterproof coating.

Hanging Mounting Magnets

Hanging hook mounting magnets add the flexibility of different hanging options.

Stainless Steel Coated Magnets

Stainless steel coated magnets offer a stainless coating and heavy-duty steel cup assembly to protect against moisture and prevent rust and corrosion.

Mounting Magnet Rubber Covers

Mounting magnet covers for impact resistance and strong grip specced out for metric sizes.

Ring Magnets

Round magnets with a hole. Magnetized axially through thickness or diametrically.

Countersunk Ring Magnets

Countersunk ring magnets have a screw hole in the center for easy mounting. The hole is angled so the screw sits flush with the surface of the magnet.

Plastic Coated Ring Magnets

Waterproof plastic coated ring magnets to prevent rust and corrosion due to water and moisture.

Rubber Coated Ring Magnets

Rubber coated ring magnets for anti-slip and strong grip as well as waterproof protection against rust and corrosion.

Diametric Ring Magnets

Diametrically magnetized ring magnets.

All Grade N52 Neodymium Magnets

Browse all grade N52 rare earth neodymium magnets in disc, block and ring shapes.

Grade N52 Disc Magnets

N52 grade disc magnets are the strongest commercially available grade of rare earth neodymium disc magnets.

Grade N52 Block Magnets

N52 grade block magnets are the strongest commercially available grade of rare earth neodymium block magnets.

Grade N52 Ring Magnets

N52 grade ring magnets are the strongest commercially available grade of rare earth neodymium ring magnets.

All High Heat Neodymium Magnets

High temperature resistant neodymium magnets can withstand heats up to 400F (220C) before reaching curie temp.

High Heat Disc Magnets

High temperature resistant disc magnets can withstand heats up to 400F (220C) before reaching curie temp.

High Heat Block Magnets

High temperature resistance block magnets can withstand heats up to 400F (220C) before reaching curie temp.

All Hook Magnets

Browse all strong neodymium magnetic hooks. Available in open hook, eye-hook, slotted hook, spin and swivel hooks and plastic and rubber hooks.

J-Shaped Hook Magnets

Strong heavy-duty open hook, j-hook magnets for hanging in industrial, commercial or home and DIY applications.

Loop Shaped Eye-Hook Magnets

Heavy-duty loop hook, eye-hook magnets for hanging in industrial, commercial or other home and DIY applications.

Spin Swivel Hook Magnets

Heavy-duty swivel spin hook spins 360 degrees and swivels 180 degrees. Offers hook close to base with rubber grip to lower leverage. Great for hanging in industrial, commercial or home organization and DIY applications.

Rubber Spin Hook Magnets

Strong grip rubber hook magnets for hanging in home, office, on fridge and for DIY applications.

Plastic Hook Magnets

Colorful plastic hook magnets for hanging on fridge, in home or office and DIY applications.

Slotted Hook Magnets

Slotted hook magnets offer both a slot and a hole and are great for hanging pictures and hanging things at multiple angles.

Fishing Magnets

Fishing magnets are super strong heavy-duty hook magnets made to lift heavy metal objects out of the water.

Single Sided Fishing Magnets

Super strong fishing magnets ideal for finding lost and hidden metal inside of lakes, ponds, streams and more.

Double Sided Fishing Magnets

Double-sided fishing magnets allow magnet fishers to catch metal objects on both sides for a wider sweep.

Hook Magnets

Other magnetic hooks for hanging from walls, ceilings, organizing things and more.

Countersunk & Counterbored Magnets

Magnets with a countersunk, counterbored or stepped hole for easy mounting and attachment with screws and other hardware. Also available in attracting pairs.

Plastic Coated Magnets

Waterproof plastic coated neodymium magnets are the best magnets for environments with wetness or moisture or for in fish tanks. They do not leach and prevent rust and corrosion to magnet.

Rubber Coated Magnets

Rubber coated neodymium magnets offer a super strong grip strength that provides high-friction and anti-slip. It also has the added benefit of being waterproof.

Stepped Magnets

Magnets with steps, slots and grooves providing a strong attachment solution for magnets in many products without the need for external hardware.

Diametrically Magnetized Magnets

Diametric magnets have polarization through or across the diameter of the magnet. Diametrically magnetized magnets are useful for sensors, side attachment and many other applications.

Magnetic Push Pins

Strong magnetic push pins in a thumbtack shape great for a colorful way to organize items on your fridge or in your home or office.

Magnetic Clasps

Strong magnetic clasps great for making accessories or other crafts and projects.

Arc Segments Magnets

Arc segment magnets are great for motors, Halbach arrays and more. They feature multiple magnetization directions and come in shapes from pie shape or wedges to thin radial magnets.

Magnetic Latches

Magnetic latches are made for doors, cabinets and drawers and provide a strong closure and have a heavy-duty build.

Magnetic Filter Rods

Magnetic filter rods are super strong and feature food grade stainless steel. They are used in magnetic grates and assemblies to remove ferrous metals from production lines etc.

Star Magnets

Star magnets are the same strong neodymium magnets in a cool star shape. Great for crafts and decorations.

Magnetic Nametag Holders

Magnetic badge holders are a safe and easy way to attach name tags, badges, ID cards and more to clothing without injury from safety pin or damaging clothing.

Stir Bar Magnets

Magnetic stir bars are a great way to mix chemicals and other things. They come in an almost non-reactant PTFE coating making ideal for mixology and mixing chemistry.

Sphere Magnets

Strong sphere magnets are great for many applications, projects and DIY.

Magnet Variety Packs

Magnet sample kits have a large variety of neodymium magnets to test for your application or to learn about neodymium magnets.

Best Selling Magnets

All of our best selling rare earth neodymium magnets in one convenient category.

New Magnets

All new rare earth neodymium magnets and other products in one category.

Telescoping Magnet Pickup Tools

Extendable telescoping magnets are the best magnets to pickup nails, screws, and other hardware and metal parts from hard to reach places. Flashlight ends available.

Fridge Magnets

Strong neodymium fridge magnets come in many colors and shapes and are the best magnets for hanging pictures, recipes, shopping lists and more on your fridge.

Craft & Hobby Magnets

Selection of best magnets for crafts, hobbies and other DIY projects.

Model & Miniature Magnets

Best magnets for Warhammer, Army Painter, model planes, trains and other models and miniatures.

Art & Sign Magnets

Best magnets for hanging art, posters and signs on walls.

Dry Erase Board Magnets

Best magnets for hanging on dry erase boards, magnetic white boards and magnetic glass.

Aquarium & Reef Magnets

Best magnets for fish tank aquariums and reefs. Waterproof plastic coating and no leaching into water.

Levitation Magnets

Best magnets for making objects levitate. Great for science projects and DIY.

Sensor & Relay Magnets

Best magnets for making reed switches, Hall sensors and other magnetic switches and relays.

Science Project Magnets

Collection of best magnets for doing science projects and other DIY projects with magnets.

Stud Finder Magnets

The best magnets for finding studs behind walls. No batteries or fancy equipment required.

Water Treatment Magnets

Strong magnets best for softening and treating hard water.

Meteorite Hunting Magnets

Magnets best for hunting meteorites. Many meteorites are ferro-magnetic and will attract to magnets.

Heavy-Duty Mounting Magnets

Mounting magnets all have a super heavy-duty steel encasing and are the best magnets for attaching to steel and lifting heavy loads.

Filter Rod Tube Magnets

Heavy-duty food grade stainless steel tube best for removing ferrous metal scrap and contamination in production lines in magnetic grate and house assemblies.

Magnetic Latches/Catches

Heavy-duty magnetic latches and catches are best for a secure closure or hold on kitchen cabinets, drawers and doors. Hardware included.

Heavy-Duty Hanging Hooks

Strong industrial and commercial grade hanging hooks with heavy-duty stainless cups are the best magnets for hanging heavy objects from steel.

Heavy-Duty Lifting/Retrieval Magnets

Super strong magnets with a heavy-duty steel assembly and strong metal loop for attaching rope. These magnets are best for lifting, mounting or securing heavy items.

Countersunk Screw Hole Magnets

Strong countersunk and counterbored magnets for firmly fastening to a surface. Simply screw magnet into recess hole and screw will sit flush with magnet surface for easy install.

Stud Finder Magnets

Stud finder magnets are best for a cheap, quick and reliable way to locate studs behind a wall with no batteries required.

Telescoping Pickup Magnets

Extendable pickup magnets are the best way to pickup hard to reach screws, nails, nuts and bolts and other metal objects.

Magnet Pole Finders

Magnet pole finders offers the best way to quickly find the North or South pole of a magnet saving valuable time.

Magnetic Thumbtacks

Strong magnetic thumbtacks are the best way to hang or attach things on a fridge, filing cabinet, magnetic glass or magnetic white board in colorful way.

Plastic Coated Magnets

Waterptoof plastic magnets are the best magnets to use in water or moist environments. The plastic coatings protect the magnet from rust and are bright and colorful to spice up your room!

Rubber Coated Magnets

Rubber coated magnets have a high-friction strong grip and are the best magnets to prevent slipping and sliding.

Magnetic Hooks

Hook magnets are the best and easiest way to hang things on a wall ceiling and many other surfaces. We offer j-hook, eye-hooks, spinning hooks, and swiveling hooks to allow for hanging in hard to hang places.

Adhesive Magnets

These magnets have a strong 3M adhesive and are the best magnets for attaching with no hardware. May not work well on all surfaces. See 3M product guidelines .

Magnetic Badge/Nametag Holders

Name tag holder magnets are the best way to attach a badge, ID or nametag to clothing without pins.

Magnetic Clasps

Clasp magnets are the best fasteners for a secure hold when making accessories or other DIY projects.

Star Magnets

Star magnets are a fun way to decorate your fridge, home or office and still are quite strong.

Sewing Magnets

Sewing magnets are the best way to make adaptive clothing with no buttons or snaps. They can also be used in curtains and offer a washable waterproof plastic case.

Magnet Sample Kits

Magnet variety packs are the best way to get a nice selection of neodymium magnets for learning, testing and sampling.

Magnet Applications

Shop best magnets for each use case or project.

Gift Magnets

Selection of the best magnets for birthday or holiday presents based on popularity and utility.

All Neodymium Magnets

Collection of all rare earth neodymium magnets divided into sub-categories by shape, function and strength.

Neodymium Magnet Applications

Collection of neodymium magnets categorized by use case. Browse this to find magnets best suited for each application.

Neodymium Magnet Accessories

Accessories to get the most out of your neodymium magnets by adding more versatility and helping to identify poles.

Other Products

Explore other magnet related products we sell.

Gift Magnets

Collection of the best magnets to give as gifts, birthday presents or for other holiday or special events.

New Magnets

Collection of all new neodymium magnets and other products.

Monthly Sales

Check out all sales on neodymium magnets. Sales change each month so be sure to stop back to see if your favorite magnets are on sale.

Clearance Magnets

Clearance sales on surplus neodymium magnets while supplies last.

Adhesive Dots for Magnets

Two-sided 3M adhesive dots to easily attach magnets to many surfaces. Bond strength varies per surface. See 3M specs.

Steel Discs & Cups for Magnets

Collection of best steel discs and cups for hanging magnets on walls.

Adhesive Non-Slip Pads for Magnets

Anti-slip pads with adhesive backing are the best way to keep your magnets from slipping and sliding down or across surfaces.

Magnet Pole Identifiers

Magnet pole finders are the best way to find the polarization direction of a magnet and which pole is North or South.

Mounting Magnet Rubber Covers

Mounting magnet covers for impact resistance and strong grip specced out for metric sizes.

Magnet Wire

Enamel coated magnet wire is best for projects that require running a current and creating a circuit.

Telescoping Magnet Pickup Tools

Extendable telescoping magnets are the best magnets to pickup nails, screws, and other hardware and metal parts from hard to reach places. Flashlight ends available.

Pyrolytic Graphite

Pyrolytic graphite is best for experiments involving diamagnetic levitation or cool displays of floating magnets!

Magnetic Viewing Film

Green magnetic viewing film is the best and easiest way to visualize magnetic fields. Can be combined with iron dust to see magnetic field lines.

Steel Balls

Nickel plated steel balls.

Magnetic Fidget Toys

Our hematite magnetic fidget toys are the best way to relieve stress. Smooth shiny finish and relaxing noise sticking together.

Magnet Fidget Toys

Fun with Magnet Fidget Toys

Horseshoe Magnets

Traditional Alnico horseshoe magnets with keeper are great. Learn more about horseshoe magnets in our Why are Magnets Shaped like Horseshoes? article.

MW30-4 Specifications

Weight: This is the weight of a single magnet in ounces and grams.

4.4 oz (124.74 g)
Color: The color of the coating or plating on the product.

Copper
Length:

800 feet
Enamel Insulation:

Polyurethane / Polyamide (Nylon)
Wire Gauge:

30 gauge
Wire Diameter:

0.0109 in (0.28mm)
Temperature Range:

-22ºF (-30ºC) to 311ºF (155ºC)
Solderable:

680°F (360°C)
Specs:

MIL JW-1177/42, MW 80-C, Class 155
Compliance:

RoHS Compliant

Magnet wire is copper wire coated with a very thin layer of insulation (it is not a magnet). It is used for various applications but is mostly used for constructing windings in transformers, inductors, motors, speakers, electromagnets, and much more!

MW30-4 Spec & Certificate Downloads

RoHS Download

Similar Products

mw24-4-magnet-wire

Magnet Wire 24ga (200ft) MW24-4

mw42-4-magnet-wire

Magnet Wire 42ga (1280ft) MW42-4

mw42-8-magnet-wire

Magnet Wire 42ga (2560ft) MW42-8

Recently Viewed Products

stir50-magnetic-stir-bar

0.374 x 1.969 x 1.969 Inch Magnetic Stir Rod N42H STIR50

Magnetization direction icon

dxc2-neodymium-disc-magnet

1 3/4 x 1/8 Inch Neodymium Rare Earth Disc Magnet N42 DXC2

Magnetization direction icon

pg5-pyrolytic-graphite-for-levitation

1.969 x 1.969 x 0.118 Inch Pyrolytic Graphite for Levitation PG5

b888-2pa-n52-neodymium-block-magnet

1/2 x 1/2 x 1/2 Inch Neodymium Rare Earth Cube Magnet N52 B888-2PA-N52

Magnetization direction icon

b888-2pe-n52-neodymium-block-magnet

1/2 x 1/2 x 1/2 Inch Neodymium Rare Earth Cube Magnet N52 B888-2PE-N52

Magnetization direction icon

r822cs-n-neodymium-countersunk-ring-magnet

1/2 x 0.136 x 1/8 Inch Neodymium Rare Earth Countersunk Ring Magnet N42 R822CS-N

Magnetization direction icon

da1-neodymium-disc-magnet

5/8 x 1/16 Inch Neodymium Rare Earth Disc Magnet N42 DA1

Magnetization direction icon

d82e-neodymium-epoxy-coated-disc-magnet

1/2 x 1/8 Inch Neodymium Rare Earth Epoxy Coated Disc Magnet N42 D82E

Magnetization direction icon

dec-neodymium-disc-magnet

7/8 x 3/4 Inch Neodymium Rare Earth Disc Magnet N42 DEC

Magnetization direction icon

mw42-4-magnet-wire

Magnet Wire 42ga (1280ft) MW42-4

nsb8-nickel-plated-steel-ball

1/2 x Nickel Plated Steel Ball NSB8

d101-n52-neodymium-disc-magnet

1/16 x 1/32 Inch Neodymium Rare Earth Disc Magnet N52 D101-N52

Magnetization direction icon

d201-n52-neodymium-disc-magnet

1/8 x 1/32 Inch Neodymium Rare Earth Disc Magnet N52 D201-N52

Magnetization direction icon

r424-neodymium-ring-magnet

1/4 x 1/8 x 1/4 Inch Neodymium Rare Earth Ring Magnet N42 R424

Magnetization direction icon

d84pc-ora-neodymium-plastic-coated-disc-magnet

1/2 x 1/4 Inch Neodymium Rare Earth Plastic Coated Disc Magnet N42 D84PC-ORA

Magnetization direction icon

47eb01-custom-neodymium-magnet

Custom Neodymium Magnet 47EB01

mm-h-25-metric-internal-thread-mounting-magnet

0.984 x 0.315 Inch Neodymium Rare Earth Internal Thread Pot Magnet N38 MM-H-25

Magnetization direction icon

db01-neodymium-disc-magnet

11/16 x 1/32 Inch Neodymium Rare Earth Disc Magnet N42 DB01

Magnetization direction icon

b841-n52-neodymium-block-magnet

1/2 x 1/4 x 1/16 Inch Neodymium Rare Earth Bar Magnet N52 B841-N52

Magnetization direction icon

mmwr-b-y0-neodymium-stainless-steel-mounting-magnet

2 x 1/2 Inch Neodymium Rare Earth Stainless Steel Pot Magnet N42 MMWR-B-Y0

Magnetization direction icon

d601-neodymium-disc-magnet

3/8 x 1/32 Inch Neodymium Rare Earth Disc Magnet N42 D601

Magnetization direction icon

dh23-neodymium-disc-magnet

2/10 x 3/16 Inch Neodymium Rare Earth Disc Magnet N42 DH23

Magnetization direction icon

558m01-custom-neodymium-magnet

Custom Neodymium Magnet 558M01

sb8x04-out-neodymium-stepped-block-magnet

1/2 x 1 x 1/4 Inch Neodymium Rare Earth Stepped Block Magnet N42 SB8X04-OUT

Magnetization direction icon

d43-neodymium-disc-magnet

1/4 x 3/16 Inch Neodymium Rare Earth Disc Magnet N42 D43

Magnetization direction icon

d203-neodymium-disc-magnet

1/8 x 3/32 Inch Neodymium Rare Earth Disc Magnet N42 D203

Magnetization direction icon

re22cs-s-n52-neodymium-countersunk-ring-magnet

7/8 x 0.194 x 1/8 Inch Neodymium Rare Earth Countersunk Ring Magnet N52 RE22CS-S-N52

Magnetization direction icon

Our Services

Free Magnet Calculators

Quantity Discounts

Quality Commitment

Magnet Specifications

Magnet Info Blog