Pack of 1 - single 4 x 3 mm N42 neodymium disc magnet on a half-inch reference grid

4mm x 3mm N42 Neodymium Disc Magnets

1
$3.39
$3.39
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Pack of 1 - single 4 x 3 mm N42 neodymium disc magnet on a half-inch reference grid
  • Pack of 1 - single 4 x 3 mm N42 neodymium disc magnet on a half-inch reference grid
  • Overview panel for 4 x 3 mm N42 neodymium disc magnets - 450 g calculated pull to steel at zero gap, NiCuNi plating, axial magnetisation
  • Stacked rows of 4 x 3 mm N42 neodymium disc magnets shown at real size on a half-inch reference grid
  • Infographic - calculated pull reference of 450 g for a 4 x 3 mm N42 disc magnet on clean flat steel with zero gap
  • Rows of 4 x 3 mm neodymium disc magnets stacked into long columns on a dark background
  • Stacked columns of 4 x 3 mm neodymium disc magnets standing upright on a dark background
  • Two overlapping groups of stacked 4 x 3 mm neodymium disc magnets on a dark background
  • Wargaming miniature parts laid out across a cutting mat with disc magnets for weapon swaps
  • Close-up of miniature weapon and body parts on a cutting mat with disc magnets fitted
  • Miniature torso on a round base with weapon parts on a cutting mat prepared for magnetising
  • Wide block of 4 x 3 mm neodymium disc magnets stacked in parallel rows
  • Magnet safety warning panel: swallowing two or more magnets can cause serious internal injury; keep away from children and medical devices, handle and store with care
  • Infographic - separating small disc magnets safely: slide sideways, keep the stack controlled, mind loose steel and blades
  • Infographic - how diameter and thickness affect disc magnet holding strength and how to read the D x H size format
  • Size chart comparing 2 x 1 mm, 3 x 2 mm and 5 x 3 mm disc magnets on a cutting mat with calculated zero-gap pull of 50 g, 210 g and 650 g
  • Infographic explaining magnet holding force: full pull at direct contact, weaker shear under sideways load, reduced hold across a gap
4mm x 3mm N42 Neodymium Disc Magnets
Hobby Heaven

4mm x 3mm N42 Neodymium Disc Magnets

$3.39
$3.39
Taxes included. Shipping calculated at checkout.
Pack Size
Number of packs

In stock · same-day dispatch before 3pm

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DWG · Product Information

PROJ: MAG/D4X3/1 · SHEET 2 / 4

View · Overview

Product overview

These 4 x 3 mm N42 neodymium disc magnets sit at the top of the 4 mm size ladder, providing the highest holding force in that diameter. They are axially magnetised for flat-face attraction and protected by a NiCuNi coating for normal indoor modelling and craft use.

Choose this format for heavier subassemblies, turrets, substantial weapon fittings and basing jobs where a 4 mm footprint is already established and the part has enough depth for a longer magnet. Its calculated, zero-gap pull reference is 450 g, while the sideways shear estimate is approximately 60 g. This makes it the option for components that should stay seated confidently during handling, rather than for thin panels or shallow shells.

Prepare the joint with a 4 mm drill and a 3.2 mm-deep recess. A 4.1 mm hole is the recommended starting point in a 3D-printed component. Check the available wall depth before drilling, keep the socket square and test polarity against the mating side before adding CA glue. The stronger joint can expose a weak adhesive bond, so allow the glue to cure fully before separating the faces. Packs contain 1, 10, 25, 50 or 100 magnets.

Notes · Q & A

Which magnet size should I choose for miniatures?

A 2×1 mm disc suits infantry weapon swaps, while 3×1 mm is a practical step up for arms and small components. Sizes around 3×2 to 5×2 mm work well for basing and larger parts, with 5×3 mm and above better suited to vehicles, large models and army transport. Each listing includes a calculated pull figure in grams so you can compare sizes on the same basis.

What does the N42 magnet grade mean?

The grade describes the magnetic material: at identical dimensions, a higher number generally produces more pull. N52 is typically around 20–25% stronger than N42 at the same size, but increasing the magnet's diameter or thickness usually makes a larger practical difference than changing grade alone. Our range is clearly specified as N42.

How do I keep the polarity consistent?

Before separating the stack, mark one face with a permanent marker and use that mark as your polarity reference. Dry-fit every pair before applying adhesive, and glue the two halves while the magnets are still attracting each other in the intended orientation. Reversing one magnet is one of the most common magnetisation mistakes.

What size hole should I drill for a magnet?

Use a drill matching the magnet diameter; for a designed 3D-printed socket, allow roughly 0.1 mm extra diameter. Make the recess approximately the magnet thickness plus 0.2 mm for adhesive so the face can sit level with the surrounding surface. CA adhesive is suitable for fixing these magnets into plastic, resin or metal parts.

How should neodymium magnets be handled safely?

Swallowing two or more magnets can cause serious internal injury, so keep loose magnets away from children and use them only for adult hobby work. Neodymium magnets are also brittle and may chip if allowed to snap together. Bring them together slowly from the edge rather than letting their flat faces strike each other.

Notes · Logistics

Shipping

Orders placed before 3pm (Mon–Fri) are dispatched the same day. UK delivery is by Royal Mail 24 Tracked. Free UK delivery on orders over £70. International delivery available via Royal Mail International Tracked or courier.

Returns

If you're not happy with your purchase, contact us within 30 days for a full refund or exchange. Items must be unused and in original packaging.

Table · Specification

Technical specifications

Product details
Brand
Hobby Heaven
Product code
MAG/D4X3/1
Type
Accessories
Shipping weight
60 g
Made in
China
Dimensions & contents
Diameter
4 mm
Thickness
3 mm
Weight per magnet
0.29 g
Magnetic properties
Grade
N42
Pull to steel (calculated, zero gap)
450 g
Pull to steel
4.41 N
Magnet-to-magnet pull
450 g
Shear resistance (estimate)
60 g
Magnetisation
Axial
Max working temperature
80 °C
Coating
Nickel-Copper-Nickel (NiCuNi)
Usage & compatibility
Drill bit
4 mm
Hole in 3D prints
4.1 mm
Recess depth
3.2 mm
Size comparison
4 mm — a 5p coin is 18 mm across
Related sizes
Also consider
4mm x 2mm N42 Neodymium Disc Magnets
8mm x 1mm N42 Neodymium Disc Magnets
5mm x 2mm N42 Neodymium Disc Magnets
10mm x 1mm N42 Neodymium Disc Magnets

Product

4mm x 3mm N42 Neodymium Disc Magnets

Code (proj)

MAG/D4X3/1

Ship. weight

60 g

Brand

Hobby Heaven

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