Brim Flange – The Workshop Ledger

A brim flange, often referred to simply as a flange, is a shaped form used to establish the profile of a hat brim during construction or renovation. After the crown has been blocked, the brim is worked into or over the flange, where heat, steam, pressure, and controlled drying help establish its intended shape.

What a Brim Flange Does

The brim flange is one of the principal shaping tools used in traditional felt hat making. Its contoured working surface provides a form against which a softened brim can be worked and allowed to set.

Unlike a hat block, which establishes the basic dimensions and profile of the crown, a flange establishes the brim’s profile. Depending on its design, a flange may produce a relatively flat brim, an upward or downward slope, a curl, or a more complex profile that varies around the front, sides, and rear of the hat.

The flange does not by itself determine the finished appearance of the brim. Felt characteristics, moisture, heat, pressure, ironing, finishing technique, and subsequent hand shaping can all influence the final result.

Flange Profiles

The shape of a brim flange determines the basic profile into which the brim is worked. Flanges may differ in the amount and direction of curl or slope they impart, and that profile may change around the front, sides, and rear of the hat.

Brim width is also an important characteristic of a flange. A flange intended for a narrow dress-hat brim may have substantially different proportions from one designed for a wider fedora or Western brim.

Two flanges marked for the same hat size can therefore produce very different results. The flange’s actual dimensions and working profile—not simply its nominal size—must be considered when selecting it for a particular hat.

Flange Size & Crown Clearance

A brim flange must provide sufficient clearance for the blocked crown while positioning the brim correctly on its working surface. For this reason, the dimensions of the crown opening are an important characteristic of every flange.

Nominal size alone does not guarantee compatibility. Two flanges carrying similar size markings may differ in crown-opening dimensions, head oval, block profile, or other design characteristics that influence how they relate to a particular hat block.

Understanding the relationship between crown clearance and flange geometry is important when selecting equipment for a workshop. The methods used to evaluate compatibility between individual hat blocks and flanges are discussed in the Hat Making & Construction section of The Workshop Ledger.

Flange Materials

Traditional brim flanges are most commonly made with wood, which provides a durable shaped working surface capable of repeated use during brim forming and finishing.

Modern flanges may also be produced through methods such as CNC machining and 3D printing. These approaches can make replacement, custom-sized, or otherwise difficult-to-find flange profiles more accessible to contemporary hat makers.

Regardless of material, a flange must maintain an accurate working profile while tolerating the heat, moisture, pressure, and repeated handling involved in hat making. Vintage wooden flanges should also be inspected for cracking, warping, previous repairs, or other deterioration before being placed into service.

Hat Blocks & Brim Flanges

Hat blocks and brim flanges perform complementary roles. The block establishes the crown’s basic dimensions and profile, while the flange establishes the basic profile of the brim. Together, they provide much of the underlying geometry from which the finished hat is shaped.

A hatter may therefore need multiple blocks and flanges even when working within a relatively narrow range of hat sizes. Different crown profiles, head ovals, brim widths, and flange profiles allow the same nominal hat size to serve as the basis for substantially different finished hats.

Using a Brim Flange

A brim flange is employed after the crown has been blocked to establish or refine the overall profile of the brim. Its contoured working surface provides the geometry from which the broader shape of the brim is developed, whether that profile is flat, sloping, curled, or otherwise contoured.

The precise methods by which the felt is worked against the flange vary according to the characteristics of the felt body, the construction of the flange, and the hatter’s preferred workshop practices. Traditional and modern methods employ different combinations of heat, steam, moisture, pressure, and supporting equipment to encourage the felt to conform to the flange’s profile.

Although the purpose of a brim flange remains consistent, the techniques used to achieve the desired result are matters of workshop practice rather than encyclopedia knowledge. Detailed procedures for flanging and brim shaping are presented in the Hat Making & Construction section of The Workshop Ledger.

Workshop Notes

In July 2026, The Workshop Ledger acquired two vintage wooden brim flanges from a private seller through a hat-making group. Both are marked size 7¾ and were purchased together for $170 including shipping. The larger flange is marked Jolly and has a recorded brim width of 2⅝ inches, while the second carries the identifying number #728 and has a recorded brim width of 1¾ inches.

The 7¾ size was selected with the workshop’s 61 cm open crown hat block in mind, with the expectation that the larger nominal size would provide additional crown clearance. Actual compatibility will be established through measurement and dry fitting rather than the marked sizes alone.

The two flanges also provide substantially different brim-width options. The 2⅝-inch Jolly flange offers a wider working profile, while the 1¾-inch #728 provides an option for narrower-brim hats. Their exact profiles—and their suitability for particular hat styles—will be determined through measurement and practical use rather than assumed from the markings alone.

Future workshop testing will document how each flange performs with different felt bodies and brim treatments, including the methods of steaming, ironing, weighting, and drying used; the resulting brim profile; and any limitations or advantages discovered through repeated use. These observations will be added as workshop experience develops.

Selected References

The information presented in this article has been synthesized from historical publications, professional hat-making sources, surviving workshop equipment, and original research conducted by The Workshop Ledger. Ongoing investigation of traditional flanging methods, historical workshop practices, and vintage brim flanges continues to refine and expand the understanding of this essential hat-making tool.

Principal sources informing this article include original research maintained within The Workshop Ledger Research Library concerning brim flanges, hat blocks, and traditional brim-shaping systems, together with observations of professional workshop practice documented by Hornskov Hat Works and research conducted using the Workshop Ledger’s own collection of vintage wooden flanges. The relationships described between brim flanges, hat blocks, crown clearance, and brim geometry represent a synthesis of available historical and modern professional sources. As additional primary sources—including historical trade catalogs, patents, manufacturer literature, and workshop manuals—are identified and verified, they will be incorporated into future revisions of this article.