Built-to-Order, Hat Making Tool, Rounding Jack, Deluxe Model, CLOCKWISE cutter, Maple Wood Adjustable Front Brass Shoe

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Arrives from the United States

Made in Elmdale, Kansas

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This custom built, handmade tool is of my own design, used by hat makers for cutting the brim to size on custom hats. The rounding jack front shoe pushes against the crown block or band block inside the hat, and the blade slices the felt a consistent distance all the way around the hat brim. This tool follows the oval shape of the crown, and cuts the brim in the same shape, at any distance you set the blade to cut away from the crown.

Below is a long list of typical questions and details that will provide further information.

I designed this tool, and hand build each one to order, doing all the brass machining, soldering, manufacturing, all woodworking and assembly. Each tool comes with my engraved signature and the date.

The cutting blade for this item is a standard Stanley Brand Utility Knife Blade, with an angled cutting position for extreme ease and smoothness of cut.

A Bench-Top, or shelf, Display Stand is also available as a separate item, shown here also in my Etsy Shop.


You can anticipate a 10-24 week wait to receive your order.


I offer several different models of this tool, this item listed is a:

This item is:
Maple Deluxe Model - Gen. 4 Design
Clockwise Cutter
Adjustable Front Brass Shoe - optimizes the front arc to best fit different blocks
Brass Under-Plate
Laser Engraved Ruler Position Indicator, with Metric and English Units
Capacity 1.125" - 8.0"


A Little History:
Several years ago I was asked by a custom hat maker to build him an improved rounding jack, something that was better, stronger, longer, and cut with an angled blade position, and it was to be much improved over the vintage models that hat makers fight over on eBay. I have a mechanical engineering degree and a woodworking business and the project seemed to be a good match, so I undertook the challenge eagerly.

To start the research phase, I visited a custom hat shop and asked a lot of questions. Then, I collected 8 different varieties of vintage rounding jacks and analyzed why they broke, or fell apart, or just why they didn't work well. I then took my research to the woodshop and built a couple of early prototypes (the 1st one I kept, the 2nd I was talked into selling), which then led to a "1st production" model that I sent to a couple of hat makers for shop testing.

After their comments came in, I improved the design some more, and what resulted is this top of the line rounding jack. I have sold many of these since, in a variety of sizes and configurations.

If you have a special situation that requires a special cutter, drop me a note and I'll consider if it is something I can tackle successfully.


I realize that this tool is a big investment. From my perspective, they take a long time to build and brass is expensive, and the sales market is so small for such a specialized tool that it doesn't make sense to outsource the parts to a factory and carry the inventory costs until one of them sells. But, I can appreciate the investment you'll be making, and how hesitant you might be in trusting my work.

Therefore, if you would like a reference list of hat makers to contact before you buy, please send me an email and I'll send you a list of my rounding jack users who can answer your questions, and testify to my work quality.


Here is a link that shows a short video by hat maker Tom Gomez from the Los Angeles area, as he quickly cuts a brim. The video shows Tom's first felt hat cut with a rounding jack.



I ship hat making tools to customers across the United States, and many international locations, and it is increasingly hard to predict the actual shipping costs. I have tried to include the cost of shipping to cover most people, but really it is just a guess until I actually hand the package across the counter to the shipping clerk.

If the shipping cost listed on your purchase seems too high to be reasonable, don't forget that once the package ships, if you have paid more than I need to cover the cost, I will refund the difference to you through Paypal, or through Etsy if you have paid with a credit card, AFTER I know the exact amount.

The need for a refund can be especially true if you have ordered multiple items and the combined individual shipping cost calculation is higher than what it will actually be when I put all of the items in one box.

BUT, don't worry, your final shipping price will be adjusted to reflect the actual cost of shipping the item to you.


For many places in the World, I can not buy enough postage insurance on any particular package to cover the cost of the contents should it get lost, or stolen while in transit. In particular, Mexico and Eastern Europe are deemed worrisome by the United States Postal system. I will insure your package for the full replacement cost if I can, and if not, I'll get you as much insurance as I can toward the actual value.

If a package is lost by the postal carrier, I will send you whatever the insurance payment is, after I receive the payment. Unfortunately, if I am unable to insure the full replacement cost, you'll only receive what insurance value I could purchase for you. Filing a Claim, and getting payment is about a 3-6 month adventure if it happens, so you'll have to be patient with UPS or the USPS if your package isn't delivered.

In all of the years I have shipped packages, only one time did UPS lose a package, and never has one gotten lost by USPS, but you do need to be aware of the risks, especially to foreign Countries that are deemed risky by the shipping company. Some Countries are deemed so risky by the USPS, that they will not insure the package at all. I'm sorry if this causes you concern, my other option is to accept USA only orders.



Below, are some typical questions I get about rounding jacks which include your questions, so I thought you might find the extra information to be helpful in your decisions.


Brim Preparation?

Brims should be ironed flat, and all subsequent brim curves, or rolls should be done after the rounding jack has cut the brim to the desired width. Very Soft Felts will require some brim stiffener. This stiffener is available in proprietary concoctions sold by several vendors on the internet, or Starch, or diluted Shellac. This stiffener gives the brim enough stiffeness that the felt will not pull or bunch up as you cut through very soft felts. For felt that is normally supplied by such vendors as Winchester, you will not need any additional brim stiffener to make a perfect cut with a rounding jack.


How is the Cut Width Set?
You decide what distance from the Crown you want the brim to cut, set the rounding jack size pointer to that dimension on the laser engraved ruler, tighten the nut, lower the blade and tighten that nut. Put the felt in between the bottom of the wood rounding jack and above the brass base plate, and push gently against the Crown and move whichever direction the model is designed to cut. After you practiced a couple of time, cutting a brim should be a matter of 15-20 seconds.


Brim Edge Smoothing?

If you hold the rounding jack consistently and carefully against the crown, when the end of the cut meets the beginning of the cut, the two cuts will meet. What you have left is a square edge. Some like to sand that edge to take square cut away, while others prefer to leave it cut square. If your cuts don't mate up as you go around the crown, you can leave a little "burr" in your cut when it is finished cutting. This "burr" can be either sanded, or trimmed smooth. If you are consistent in your method, a perfect cut, without a "burr" is typical of experienced users.


Clockwise vs. Counter Clockwise vs. Uni-Directional?

Cutting Direction: The blades are set at an angle so that they shear the felt easier. That requires me to lay the blade to one side, and so I have to pick which direction the rounding jack will move, thus Clockwise (CW) or Counter-Clockwise (CCW). I do have the Uni-Directional design for hatters that can not pick a direction, or have an application that requires going both CW and CCW.

Nearly every hat maker picks a direction they think works best for them, and then they stick to that direction. There seems to be no preference over going a certain direction based on being right handed or left handed.

I personally would prefer to pull the tool in a Clockwise manner, but the majority of orders have been for Counter Clockwise, but not a big majority. Over the years that I've built rounding jacks, I've sold dozens and dozens of them, and it's worked out to about 60% want the Counter Clockwise direction, and 39% want Clockwise, and the balance have been the Uni-directional cutters.

The Uni-Directional blade holder holds the blade in one direction. To reverse and go the other way, you have to remove the brass nut, pull off the blade holder cover, turn the blade over, and assemble it all back together. Takes about 10 seconds or so once you have the hang of it.

The uni-directional blade holder holds the blade in a straight up and down position. The other styles hold the blade at an angle of about 45 degrees. The advantage of the angled position is that the blade slices easier, but the uni-direction blade cuts well also. I suppose the main advantage of the angled position is that the blade can be a little more dull and still cut smoother. But, with a sharp blade, both styles cut well.


Brass vs. Wood Blade Holder:

The wood blade holders work great. The people that buy the brass blade holder models like the appearance as the top reason, and then they appreciate the heaviness of the tool. That machined brass is thick, and so it adds a nice weight to the tool. What that does for me and the folks that have ordered it, is that they just like the "feel" of it, but I don't know that any of us could prove that it does a better job.

The Machined Brass is something I personally do in my shop, and the time it takes to machine, sand, polish, and hand file, etc. to get the brass to look good and the blade holder to work great, takes some time. Time is money, and so the brass model is more expensive than the wood blade holders.


What Shape do Rounding Jacks Cut?

Rounding Jacks cut a consistent distance away from the crown block. You set the tool at something like 7.5cm, and as you use the tool to cut, and the brim will be 7.5cm all the way around the elliptical crown block.

There is a size indicator brass point, you just set it on the ruler increment you want, tighten the slide thumbnut, slide the blade down and into position and tighten it, and you are ready to cut without needing to use a tape measure or marking the felt.

After you've done it a couple of times, you can reasonably expect to perfectly cut a brim to the width you want in a matter of 30 seconds, or less.


What Is the Adjustable Brass Shoe on the Front Curve for?

The only exceptions to cutting the brim the same width all the way around, is if you use the models that have the adjustable front brass "shoe". This adjustment allows you to make the radius on the front of the rounding jack smaller.

What this does, as you move around the crown block cutting the brim, you'll cut the front/back of the hat to the setting on the rounding jack, and as you move around to the sides, the cutter will be gradually moved away from the crown block. This produces a cut that is called a "dimensional brim" style, where the sides are wider than the front/back.

The difference in width isn't extreme, depending on the crown block size, you could expect maybe in the range of 3mm-12mm wider on the sides of the brim. You would set the front shoe in the position that best fits the crown block you are using, to get the sides cut to the width you want. Typically, hatters set the front shoe to fit the front of the crown block, matching the curve, and then as they move around to the sides, the "dimensional brim" style is cut wider on the sides of the hat.


What To Do if You want To Cut the Front/Back Longer than the Sides?

If you are wanting to cut any other profile of brim shape than a consistent width, or the "dimensional brim" (wider sides), you will have to do it another way, as the rounding jack will not cut any other way.

For brims that are not the conventional, making a template that has the profile of the cut on the edge, and a hole in the middle to fit over the crown block is about the only way a non-factory crafts person has to cut brims.

The cutting is then done by marking with chalk and using scissors, or a razor knife following the edge of the template. Any shape can be made this way, but you have to make your template first.

I've considered offering these templates for sale, but I just have too many other hot irons in the fire to get that done, and everyone would something different, so it would be hard to guess ahead of an order what someone would want to buy.

So, right now, hatters will have to make their own out of cardboard or plywood. The profile will need to be made from stiff material, and you can use either a sharp knife, or a rolling cutter to follow the template.


What Blades does the Rounding Jack Take?

The blades are Stanley brand Utility Knife blades. The blades run in price of about 100 blades for around $17.00 USD at this time. When the blade gets dull, you pull off one brass thumbnut and remove the blade, put a new blade in the blade holder, and reattach the blade guard and thread the thumbnut back on. Takes about 10-15 seconds to change the blade, so it's pretty easy.


Will The Rounding Jack cut my Handmade Felt?

Cutting Wool: The rounding jack works best using commercially prepared felt, any material is fine. For home-made felt, where the felt is very soft, adding a stiffener to the felt is recommended. What happens with really soft felt is that as you move the rounding jack around the hat, the soft felts are not easy to keep flat. The blade is sharp, and with the angled position of the blade, it cuts very easily, but the felt needs to stay fairly flat to get a smooth consistent cut.

I had a customer that was trying to cut very soft alpaca wool felt that she was making herself. She added a stiffener solution to make the brim more stiff, and she ironed it down smooth and flat, and that solved her problems. Stiffeners generally come in either a Starch-base, or a Shellac-base. Some hat makers make up their own stiffener solution, while others order it from the internet where it is made up for application with a spritzer spray bottle.


What are the different Models, and Which Model does What?

Different Models:

Hobbyist Model: Least expensive, cuts a brim width ranging from 3cm-15cm (1.125"-6"). This model does not have the decorative blade holder, and does not have the adjustable front brass shoe.

Artisan Model: Same as the Hobbyist, but with a brim width ranging from 3cm-20.3cm (1.125"-8")

Deluxe Model: This model is the same as the Artisan, although the front curve has the adjustable brass front shoe.

Collector Model: This model is the same as the Deluxe, although I use thicker brass sheet metal, and the blade holder is machined from brass. Some of these have been personalized with laser engraving, and other features to make them special for the hat maker ordering them.

Uni-Directional Model: This model is shown in the Collector Version, however, I could make this style blade holder in wood for any of the models upon special request. This blade holder allows you to go either Clockwise or Counter Clockwise.

Decorative Blade Guards: I have found that hat makers admire finely made tools, they like to use them, display them, and collect them. So, I offer small added cosmetic wood colors to the blade holder bar just to dress them up. So, some of the models will show a "decorative blade holder" listing, while others will have a plain wood.


Is there a Video to Watch?

Here is a short video of a hat maker using one of my rounding jacks, you can go to this link to find the video:



Can I Get The Display Stand Free with the Rounding Jack?

The Display Stand is not sold with the rounding jacks, there is a separate listing for that item. I can make those in walnut, maple, or oak right now, and I've also done them in black stained wood which looks pretty cool also.


What is the Warranty on the Rounding Jacks?

I don't really have a stated warranty on the hat making tools. If someone has a problem, I try to fix it, but it rarely happens. I want life-time customers, not single purchase customers, so I try every thing I can to make reasonable people happy.

If someone were to change their mind and want their money back, if I can do that, I will, but I first try to modify, or make it work for them.

There's no one here but me, so if I'm gone, that's it, and nobody else here can help with warranty issues. I don't have any money or assets to sue for, so going to court isn't going to help, so I try to keep people happy so they blog and post about me in a positive way. Social Media is a big scare for all of us in home-based internet businesses, and I want positive things said about me, and that helps you, gives me the incentive to do my best.

Also, it's never happened, but if the tool is kept for quite awhile and then someone wanted their money back, I'd consider that, but I'd not feel obligated to do that past a certain reasonable point, maybe after several weeks of using the tool.


I have sold a lot of rounding jacks over the years. But, if you still don't trust my word, and want to talk to actual users/customers of my rounding jacks, let me know and I can get you a few names that have agreed to answer questions. Realize that most hatters don't enjoy sharing information about the craft to competitors, but a few have agreed to give testimonials about the tools I have made for them over the years. They are not however, to be considered as free advisors on hat making, and they most likely won't answer those types of questions....just letting you know ahead of time.

If you have any questions, please check out my website www.decoustudio.com where I have my email address listed in the "Contact Me" section.

Mark DeCou

    Average review
    Over the moon with my new rounding jack!!
    Jun 30, 2015 by missjereira

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