Hat Making Tool: DeCou Rounding Jack, Maple Deluxe Model, Clockwise Cutting, for Hat Brims

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Project by Mark A. DeCou posted 04-19-2008 09:50 PM 10236 views 1 time favorited 9 comments Add to Favorites Watch


If you’d like one, email me and we can discuss what tools I have on hand, or what the current delivery schedule will be for custom made tools.

email: [email protected]


Video: What does this thing do? Watch this video by California Custom Hat Maker Tom Gomez from Premier Panama Hats using one of my Rounding Jacks on a felt body Hat. Here is a link to Tom's ebay Store

To See More Hatmaking Tool Videos from Tom Gomez:
  1. Foot Tollikers: click here to see
  2. Kettle Curling Tool: click here to see one
  3. Puller Downer: click here to see one:
  4. Pusher Downer: click here to see one


This item is a Hat Making Tool that I designed and built.

Maple & Walnut Wood
Brass Adjustable Crown Shoe
Brass Under-Plate
Cutting Capacity: 1.25” – 8.0”
Abalone Shell Inlay


Customer Testimony Printed w/ Permission:
Hi Mark,
I picked up the rounding jack from Customs yesterday, and just cut
the first brim with it. Thank you so much for this wonderful tool! I
never dreamed that it would be so easy to work with, almost cut the brim
itself! Thanks for this great piece of craftsmanship.

Have a nice weekend!
Best regards
Thomas Osygus – Germany

Website: ad Vintage Fedora


Project Story:

Rounding Jacks are used to cut the brim felt to size on fedora, western hats, cowboy hats, and several other styles. The brass adjustable curve on the front is placed against the crown, and then the cutter is moved in a rotation around the hat, keep the pressure against the crown. Setting the blade to the proper size is done by adjusting the cutter to the desired cut size, and then tightening the brass knurled knobs.

Display Stand: The display stand is designed to sit on the hatmaker’s work bench and hold the cutter when it is not being used. The retractable blade can remain extended this way between uses. This particular stand shown in the photos is Black Walnut. This display stand is meant to make the whole project look like a functional-art sculpture, while it serves it’s functional purpose of the Rounding Jack safely.

To make the cut. The blade guard knurled nut is loosened, the blade dropped down and the nut retightened. The slider nuts are loosened and the desired cut width is indicated by the pointer, and the slider nuts are tightened. The hat is placed on a wood crown block to give a firm resistance to the pressure being applied with the cutter, and the brim is placed between the bottom brass plate and the bottom of the cutter. Then, depending on whether the hatmaker is a Clockwise, or a Counterclockwise cutter, the Rounding Jack is slowly moved around the contour of the crown while pushing the cutter toward the center (head). Felt Hat Blanks are very expensive, so after the cutting is complete, a big sigh of relief is heard from the hatmaker.

The Adjustable Brass Crown Band on the front of the cutter is used when the brim is to be cut wider on the sides, than on the front and back. By adjusting the curve of the brass band, the cutter is pushed away farther on the wider curve of the crown sides.

- – - – - – - – - – - – - – - – - – - – - – - – - – - – - – - – - – -

Here is a Slideshow with more of my Rounding Jacks Shown
Click the “Speaker” icon for music


Artisan Hat Tools by Mark DeCou Studio
(Do you want to see More? Just follow these links):

ARE LISTED IN MY ETSY.COM ONLINE SHOP, click here to check inventory

Rounding Jacks, Collector’s Editions:
  1. Ebonized Walnut Clockwise with Laser Engraving
  2. Walnut Counter Clockwise w/Laser Engraving
  3. Walnut Uni-Directional Cutter
Rounding Jacks, Deluxe Model:
  1. Maple Deluxe Model, Counter Clockwise Cutter
  2. Maple Deluxe Model, Clockwise Cutter
  3. Walnut Deluxe, Counter Clockwise Cutter
  4. Walnut Deluxe, Clockwise Cutter
Rounding Jacks, Hobbyist-Hatter Model:
  1. Walnut Hobbyist-Hatter Model, Counter Clockwise Cutter
  2. Walnut Hobbyist-Hatter Model, Clockwise Cutter
Bench-Top Display Stands for Rounding Jacks:
  1. Walnut Bench-Top Display Stand
  2. Oak Bench-Top Display Stand
    Click here to check inventory
Customized Rounding Jacks, Personalized for Specific Hatters:
  1. Spradley Hats in Apline, TX
  2. Rachel Pollock of La Bricoleuse
  3. Brainpan Hat Shop in Sumner, WA
  4. Steve Delk's Adventurebilt Hat Co.
  5. Marc Kitter's Adventurebilt Hat Co.
  6. Pyrate Trading Co.
  7. Hatman Jack at Wichita Hat Works
  8. Inaaya Hat Co.
  9. Penman Hat Co.
Formillons & Conformateurs:
  1. Complete Restoration of a Maillard Conformateur and Formillon
  2. New DeCou Formillion & Conformer, Prototypes #1 & #2
  3. Custom Designed Conformateur Carrying & Storage Case
  4. New Plot Base Board for the Maillard Allie Formillon
  5. Maple Wrench for Tightening Formillon Thumbnuts
Foot Tollikers:
  1. Left-Handed & Right-Handed Foot Tolliker
  2. Foot Tolliker: Elk Antler & Birch Wood, on a Display Stand
  3. Foot Tolliker: Walnut Wood, on a Display Stand
  4. Foot Tollikers: Three in White Birch Wood
  5. Foot Tollikers: Walnut Wood Set of Four
  6. Foot Tollikers, Birch Wood Double Set, on Display Stand
Brim Edge Curling Tools:
  1. Hinge-Shackle Curling Tool for the Homburg Hat
  2. Full Circle Shackle Curling Tool
  3. Half Circle Shacking Curling Tool
  4. Groove Tolliker Curing Tool
Band Blocks:
  1. Thick Poplar Wood, Various Sizes and Oval Shapes, with Tapered Sides
Crown Blocks
  1. Long Oval Crown Block Sculpting Work
Hat Block Spinners:
  1. Late Turned Hat Block Spinners
Flange Stands:
  1. Heavy Duty Flange Stands
Puller Downers:
  1. Puller Downers
Pusher Downers:
  1. Pusher Downers
Hat Racks, Hat Stands, & Cedar Band Blocks:
  1. Hat Racks to keep oval shapes
Stainless Steel Slip Stick:
  1. “Coming Soon”, please check back.

(Note:This project story, project design, and photos are protected by copyright in 2008-2010 by the Author, M.A.DeCou., all rights reserved, no use allowed without expressed written permission.)

-- Mark DeCou - American Contemporary Craft Artisan -

9 comments so far

View Roger Strautman's profile

Roger Strautman

657 posts in 4742 days

#1 posted 04-19-2008 10:30 PM

I’m sure the customers will come in time. Nice prototype!

-- " All Things At First Appear Difficult"

View Karson's profile (online now)


35211 posts in 5009 days

#2 posted 04-19-2008 10:47 PM

Great looking tool Mark. Good luck on the sales to follow.

-- I've been blessed with a father who liked to tinker in wood, and a wife who lets me tinker in wood. Appomattox Virginia [email protected]

View ChicoWoodnut's profile


904 posts in 4424 days

#3 posted 04-19-2008 10:53 PM

It looks like you have found a niche that could at least keep you in wood for more ambitios projects (not that this isn’t abitious :)

-- Scott - Chico California

View jockmike2's profile


10635 posts in 4855 days

#4 posted 04-19-2008 11:26 PM

Go for it buddy. Build them and they will come. People still where a lot of custom hats out there. mike

-- (You just have to please the man in the Mirror) Mike from Michigan -

View Mark A. DeCou's profile

Mark A. DeCou

2008 posts in 5014 days

#5 posted 04-20-2008 02:48 AM

Now, Mike, if you want to help me, you just need to buy some hats. If you need any references on where to buy a good one, let me know. The more hat buyers there are, the more hatmakers there will be, and the more Brim Jacks I can build. See, the circle of life.

I hate to think of the skin cancer that is headed toward my generation who have only worn baseball caps with our ears exposed. I quit doing that several years ago, but it will be a hard lesson for the rest of us I fear.

Thanks for the comments everyone,

-- Mark DeCou - American Contemporary Craft Artisan -

View Grumpy's profile


25952 posts in 4459 days

#6 posted 04-20-2008 03:56 AM

Not onlt a useful tool Mark but a very presentable one as well.

-- Grumpy - "Always look on the bright side of life"- Monty Python

View Dan'um Style's profile

Dan'um Style

14182 posts in 4591 days

#7 posted 04-20-2008 04:34 AM

well done. looks like it was fun to make. good research.

-- keeping myself entertained ... Humor and fun lubricate the brain

View Obi's profile


2213 posts in 4845 days

#8 posted 04-20-2008 06:57 AM

So… have you made any hats yet? I wanna see them when you do. Might not be a lumber thing, but the knives are bone and steel, so hey, work it.

My money guy has about 2 dozen hats of various shapes and styles, so I’ll pass the link on to him.

View Lee A. Jesberger's profile

Lee A. Jesberger

6866 posts in 4588 days

#9 posted 04-20-2008 12:43 PM

Hey Mark;

It is very good to see you’re finding new / old products to work on. This prototype you have shown here will work for cutting circular shapes in veneers.

It is somewhat like the cutter I made to cut veneer borders on table tops. (although mine were pretty simple in design and function, and were not adjustable).

Item number 7. Wouldn’t that be a Hat Puller Downer?

NIce stuff.


-- by Lee A. Jesberger

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