Neodymium magnets with a hole is a frequent search phrase, and it covers two different published figures that belong to two different shapes. This guide separates them, so that a buyer asking for a magnet with a hole can say which hole is meant and have the inquiry checked against the right table. The two figures are the countersunk hole, M1 to M10, belonging to the countersunk shape family, and the ring inner diameter, 1.5–150 mm, belonging to the ring and tube shape family. No other hole figure is published on this site.
The countersunk hole
The countersunk shape range lists round and rectangular outer forms as customized, a countersunk hole of M1 to M10, standard tolerance ±0.05 mm and minimum ±0.01 mm, and directions axial and through thickness. A countersunk hole is a recessed hole shaped so that a screw head can sit flush with the magnet face, which is the geometric reason for the shape. An inquiry for a countersunk magnet needs the outer form, the hole size in the M range, the grade series and the direction, and the outer dimensions where the form is rectangular. A hole size alone, without a form, does not describe a countersunk magnet, and a form alone, without a hole size, does not describe one either.
The screw that will sit in the hole is a separate matter for the inquiry: its size beyond the published hole range, its material and its length are not assumed here. If the countersunk magnet must sit in a housing, the mating dimensions belong in the inquiry as well, because a magnet that matches its own table but not its housing will need a second round of questions. The countersunk detail page is the specification source for this shape, and its photograph shows a round and a rectangular countersunk magnet with the central hole visible.
The ring inner diameter
The ring and tube range lists an outer diameter of 3.0–200 mm, an inner diameter of 1.5–150 mm and a height of 0.5–50 mm, with standard tolerance ±0.05 mm and minimum ±0.01 mm, and directions axial, diametrical and radial. The inner diameter is a through opening, not a recessed screw hole, and it is measured as a diameter in millimetres, not as an M thread size. An inquiry for a ring needs the outer diameter, the inner diameter and the height together, because a ring without an inner diameter is indistinguishable from a disc, and the two shapes have different tables.
The direction list is where ring and countersunk inquiries most often cross-contaminate: rings list diametrical and radial, countersunk shapes list through thickness, and neither list should be borrowed for the other shape. A ring inquiry that copies through thickness from the countersunk list, or a countersunk inquiry that copies radial from the ring list, has mixed two tables. Checking the direction against the list for the shape named in the inquiry catches the error before it becomes an order, and the magnetization directions guide collects all six lists for that check.
When the part needs both features
Some parts genuinely need both features: a ring whose face also carries a countersunk recess, or a countersunk magnet whose hole also serves as a through opening. Those parts should be described as combinations, with both sets of figures stated explicitly, and the inquiry should ask whether the combination can be made rather than assuming one table covers it. The custom-shape route is the correct channel for a combination that falls outside both published tables: send a dimensioned sketch with both features labelled, the grade series, the direction described in plain words, and the operating temperature, and the review can confirm feasibility instead of the buyer having to force the part into the nearer table.
A forced fit is the failure mode to avoid: ordering a plain ring when the part needs a countersunk recess produces a magnet that matches its order and fails its fixing, and ordering a countersunk magnet when the part needs a through opening produces the reverse. Naming the hole type at the start — countersunk recess or through opening — is a single sentence that prevents that failure, and it is worth writing even when the rest of the inquiry is already long.
Questions to send with a magnet-with-hole inquiry
A specification that can be answered names four items together: the shape family, dimensions inside that family's published range, the grade temperature series, and the magnetization direction exactly as listed for that shape. Add the operating temperature and the fixing method where they affect the choice, and ask coating and warranty as open questions. Please confirm minimum order quantity and lead time before ordering. Warranty terms are unavailable on the published pages — please confirm warranty terms before ordering. Certificates are available upon request; no certificate number or issuing body is published here.
An inquiry that names only a grade, or only a size, will be answered with questions rather than a confirmation, because neither item alone is a complete specification. The extra sentence that states the direction in plain words, or that gives the mating dimension for a fixing, is often the sentence that prevents a second round of correspondence, and it costs nothing to include at the start.
Frequently asked questions
Which grade series should I discuss for neodymium magnets with a hole guide?
Discuss the grade series against the shared grade maximum working temperature table, using the temperature the magnet will actually see in service, including heat from neighbouring parts. The series run from N35–N52 at 80°C through the M series at 100°C, the H series at 120°C, the SH series at 150°C and the UH series at 180°C to the EH series at 200°C. State the operating temperature as a figure in the inquiry, because a grade name without its temperature row has not been specified for a warm environment, and the review needs the temperature to confirm the series discussion rather than infer it from a name alone.
How exactly should I state the magnetization direction?
Copy the direction exactly as listed for the shape named in the inquiry, and do not substitute a synonym that feels equivalent, because the same word can describe a different arrangement on a different shape. Where a drawing uses a different convention, add a plain-words description of the pole positions alongside the listed term, so the review can reconcile the two without guessing. A direction that is assumed rather than confirmed is a common source of a magnet that is dimensionally correct and magnetically wrong for its fixing, so the extra sentence describing the poles is worth writing even in a short inquiry.
What should I ask about coating, warranty and certificates?
Please confirm coating requirements before ordering, because coating type names were not transcribed from the company illustration and no coating type is named on this site; state the operating environment with the coating question so the answer can be specific. Warranty terms are unavailable on the published pages, so please confirm warranty terms before ordering rather than assuming a term. Certificates are available upon request: name the certificate required and its purpose in the inquiry, because no certificate number, issuing body, scope or validity period is published here, and a named request can be matched to the order it belongs to.
What if my size or combination is not in the published range?
Ask whether it can be made, and send the dimension as written rather than rounding it into the published range. A value outside a shape range, a direction not listed for that shape, or a combination of features from two shapes should be raised as an explicit question, with a dimensioned sketch where the geometry is curved, holed or otherwise not captured by a single size figure. Please confirm minimum order quantity and lead time before ordering. A question asked before ordering costs one message; a forced fit into the nearest published table can cost the whole part, because a magnet that matches its order and fails its fixing is worse than an extra round of questions.