Miniature bases: sizes and magnet pockets

What the Warhammer 40,000 Base Size Guide actually covers

The Warhammer Design Studio guide is marked “Last updated: June 2025”. It presents base sizes considered appropriate for Warhammer 40,000 models used in matched play and says the information is not a requirement for every game. It advises checking with the organizer for some models marked Unique. Before an event, check the document version and organizer rules; a dated list does not prove current acceptance of a model.

This list covers one game and one context; it does not define bases for other systems or magnet pockets. Keep the version consulted and exact unit name with your project measurements. The site’s miniature-printer guide can help explore another project question.

Two named rows: Battle Sisters Squad and Custodian Guard

In the consulted guide, Battle Sisters Squad is listed at 32 mm and Custodian Guard at 40 mm. The same list gives other values for units in those factions; look up the exact unit row rather than inferring size from faction name. Keep the listed unit name and the date of the version used with the file’s diameter.

The list has separate rows for related models, including Repentia Superior and Sister Repentia. For your file naming, a unit name, base value and guide version/date distinguish files. This naming convention is an organizational suggestion, not a Warhammer Design Studio requirement.

Reading the notation: round, oval, Hull and Unique

The consulted guide uses several notations: a round diameter, two dimensions for an oval, and “Hull” for some vehicles. For example, Vertus Praetors is listed on a 75 × 42 mm oval base, while Sororitas Rhino is listed as Hull. Preserve the notation from the exact row; do not convert Hull into a base diameter.

For a working model, you can organize round, oval and Hull rows into separate file categories. The guide provides listed base sizes, not thickness, underside profile, bevel or magnet position. Define those design dimensions separately and check them in your model.

What the S-05-02-N52N magnet datasheet says and leaves out

The supermagnete page describes disc S-05-02-N52N: 5 mm diameter, 2 mm height, ±0.1 mm tolerance, axial magnetization, Ni-Cu-Ni coating, N52 grade and a listed maximum operating temperature of 65 °C. It also lists manufacturer pull and shear forces. These product values do not characterize a magnet installed in a base or facing another magnet.

The manufacturer’s listed forces are not a retention measurement for a magnetized miniature against a transport tray. The sources do not describe that setup, counterpart, depth, adhesive or print. Treat this disc as a dimensional example; assembly performance would need separate measurements.

An original pocket worksheet with hypothetical clearances

The published ±0.1 mm tolerance describes the magnet, not your printer’s compensation. You can treat pocket diameter as a test parameter around nominal, without assuming a universal value. Print a coupon with several labeled pockets, then measure the magnets and resulting bores before selecting a base dimension. As an adaptable coupon example, label three CAD diameters of 5.0, 5.1 and 5.2 mm without calling them recommended clearances. Then record the actual printed diameters and each magnet diameter. Pocket diameter minus magnet diameter gives a diametral difference; distinguish that from radial clearance. A chosen CAD dimension is not yet a physical measurement.

For depth, choose in your design whether the magnet sits flush, recessed or proud; the product page prescribes none of these. Measure the actual magnet and printed pocket with a suitable method, and mark polarity if the assembly uses a second magnetic part. These are suggested checks, not a validated assembly result. The dimensional-accuracy page is further reading, not proof that every printed hole comes out smaller.

Organize project files and measurements

For each base, record the exact unit name, listed size and version/date of the Base Size Guide used. Separate these project facts from parameters you choose, such as base thickness, magnet pocket and surface relief. This sheet helps distinguish a source value from a dimension you added.

For round, oval and Hull entries, keep the source labels in the design table and note which geometries still need modeling. These categories do not mean every vehicle needs a printed base; the source row may simply list Hull. Save model versions and test-coupon results together. To recover the parameters associated with each variant, you can also record the exact magnet, tested depth and chosen polarity to recover your assembly parameters. A useful check sheet can keep four columns: the value copied from the guide, the dimension you created for the base, the measurement of the magnet actually used, and the measurement of the printed pocket. On a separate coupon, label each diameter and depth variant before printing. After cooling, measure the parts without forcing the magnet; record whether insertion is loose, tight, or impossible, then adjust only the relevant parameter. That record describes your sample and setup, not a general printer tolerance. Keep material, orientation, layer height, and test date with the file so you can reproduce the comparison. If a base row changes in a later guide, duplicate the project record and update only the source value; do not overwrite the earlier measured version. For a two-magnet assembly, mark polarity and test the actual pair in the chosen orientation, since the cited magnet listing gives product data rather than performance for that assembly. A concise record can therefore separate three decisions: which source row was selected, which nominal magnet dimensions were modeled, and which coupon result informed the final pocket. If any of those inputs changes, keep a new version instead of treating the old fit as transferable. This makes the design reviewable without presenting a proposed workflow as a completed physical test. Identify each row by unit name, not faction alone.

Sources and limits

• Warhammer Design Studio — Base Size Guide, June 2025
• supermagnete — S-05-02-N52N, disc magnet 5 × 2 mm

We organize manufacturer and community documentation; we have not measured these products ourselves. The manual for your exact model takes precedence over general guidance.