Radial magnetization is listed for ring and tube magnets, alongside axial and diametrical. This guide explains what radial means on a ring, why it must not be confused with diametrical, and what an inquiry for a radial ring should contain. The ring range — outer diameter 3.0–200 mm, inner diameter 1.5–150 mm, height 0.5–50 mm, standard tolerance ±0.05 mm and minimum ±0.01 mm — is published on the ring detail page, and this guide is a companion to that page, not a replacement for it.
What radial means on a ring
On a ring, radial magnetization runs outward from the centre toward the circumference, or inward from the circumference toward the centre, depending on the arrangement described. The poles are therefore arranged around the ring's circumference rather than on its two flat faces, which is what distinguishes radial from axial, and the arrangement around the circumference is what distinguishes it from diametrical, where the poles sit on opposite sides across a diameter. Picturing the pole positions before ordering is the cheapest check available: a ring that looks identical from the outside can carry an axial, diametrical or radial arrangement, and the outside gives no clue.
Because the three directions share the same dimensions, a radial ring inquiry that omits the direction is indistinguishable from an axial or diametrical inquiry with the same figures. The direction term is therefore not optional detail; it is one of the four items a complete inquiry must contain, alongside shape, dimensions and grade series. Copy the term radial exactly as listed for rings, and if the drawing uses another convention, add a plain-words description of the pole arrangement so the review can confirm the match.
Radial versus diametrical, and radial versus axial
The diametrical confusion is the common one, because both terms involve the diameter, but they describe different pole arrangements and must not be substituted for each other. A buyer who means radial but writes diametrical has specified a different magnet, and the error will not be caught by checking dimensions, because the dimensions are identical. The axial confusion is different in kind: axial puts the poles on the two flat faces, which is easy to picture but easy to assume by default, especially when a drawing shows a ring in cross-section and the reader infers a direction that was never stated. In both cases the safeguard is the same: state the direction explicitly, check it against the ring list, and do not let a drawing's silence become an assumed direction.
The magnetization directions guide collects all six per-shape lists, and a radial ring inquiry should be checked against the ring list specifically, not against a general direction list. That discipline — direction checked against its own shape — is the single rule that prevents most direction errors on this site, and rings are where it pays off most, because rings list three directions where some shapes list only two.
Geometry, temperature and fixing for a radial ring
State the outer diameter, inner diameter and height together, each inside the ring range, and name the tolerance the drawing requires from the ring tolerances. Discuss the grade series against the shared temperature table using the temperature the ring will actually see, from 80°C for the N35–N52 series to 200°C for the 28EH–38EH series, with the M, H, SH and UH series between. Describe the fixing: whether the ring sits on a shaft, inside a housing or against a plate, and what mating dimensions constrain it, because a radial ring's working arrangement often depends on what surrounds its circumference.
Coating is an open question for radial rings as for every shape here: please confirm coating requirements before ordering, since coating type names were not transcribed from the company's illustration. If the ring is part of an assembly, name the assembly category separately and give the assembly its own dimensions, rather than assuming an assembly parameter from a category name. The assemblies page lists eight names with no per-category figures, and that separation keeps both specifications checkable.
Questions to send with a radial ring 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 radial ring magnet 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.