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American Ceramic Supply Company highly recommends to all of our ceramic customers to use Orton Cones when firing their projects for best results. Not only do you need Orton Cones if you have a manual kiln, but using Self Supporting Cones ‘on the kiln shelves’ is the best way to see what is really going on inside your kiln during the firing process. Inspecting the Self Supporting Shelf or Witness Cones after firing will aid you in determining if your kiln is firing properly and to the right temperatures. Firing to the right temperatures, ‘on the shelf’, is necessary for the maturity of your clay bodies and glazes. Choose from the Cones - all Cones come in boxes of either 25 or 50 - and then e-mail us with your list and quantities, name, shipping address - and we’ll get back to you with availability, your costs and shipping for your approval before purchase. If you have a sales tax certificate or are tax exempt, please e-mail us with that information for confidential wholesale pricing. Copies of sales tax certificates or exemption status forms must be on file before we can quote wholesale pricing.

What you should know about Orton Cones
Why Use Pyrometric Cones
- Cones have been used in firing ceramics for more than 100 years. They are useful because they can determine when a firing is complete, or if the kiln was provided enough heat, or if there is a temperature difference in the kiln, or if a problem occurred during the firing.
What is a Cone? - Cones are slender pyramids made from about 100 carefully controlled compositions. They bend in a repeatable manner over a relatively small temperature range (less than 50F). The final bending position is a measure of the amount of heat absorbed. We refer to one cone number as being hotter or cooler than another. The coolest cone number is O22 and the hottest is 42. The first cones were numbered from 1 to 20. When cooler cones were developed, an 'O' was placed before the number. So cones cooler than Cone 1 increase from O1 to O2, etc. to O22.
Cone Bending - Both temperature and time and sometimes atmosphere affect the final bending position of a cone. Temperature is the predominant variable. We refer to the temperature as an equivalent  temperature, since actual firing conditions may vary somewhat from those in which the cones were originally standardized. Using charts available from Orton, an equivalent temperature can be determined by measuring the final bending position of the Cone, if the heating rate is known. Orton Self-Supporting Cones duplicate their bending behavior with a standard deviation of 2.4 angular degrees or less than + 2C.
How are Cones used? - Cones are used as witness cones located on a kiln shelf near the ware or in a kiln shut off device (e.g.  Kiln-Sitter®). The cone bends when glass forms and it becomes soft. The composition of the cone and the amount of heat determine when and how  much glass is formed. It is important to note that it is the weight of the sensing rod that causes the cone (or bar) in a Kiln-Sitter® to bend. Changes in weight affect the bending of the cone. A witness cone bends because of gravity acting on it. Therefore, mounting height and angle is important. The higher the cone or the more it leans over at the start,  the more gravity affects bending, causing early bending. It is for this reason Orton developed Self-Supporting Witness Cones some 20 years ago,  where mounting height and angle is fixed. It typically takes 15 to 25 minutes for a cone to bend, depending upon the cone number. The cone bends slowly at first but once it reaches the halfway point, it bends quickly. When the cone tip reaches a point level with the base, it is considered properly fired; however, the difference between a cone  touching the shelf and a cone at the 4 o'clock position is small and rarely affects the fired results.

Orton Cones bars

Orton Pyrometric Cone Bars
For use in a Kiln Sitter

Orton Cones Small Sitter Cones

Orton Pyrometric Cones
For use in a Kiln Sitter

The Orton Three Cone System

Orton Three Cone System Cones

Orton Pyrometric Cones -
Self Supporting
For use on a kiln shelf - use with both manual and automatic or digital kilns for best results.

American Ceramic Supply Co - Cone Chart - copyright

Cone 10     9     8     7     Cone 6    Cone 5      4      3      2      1      01   02   03   Cone 04   Cone 05   Cone 06   Cone 07   08   09 and    up to Cone 018
_______________________________________________________________________________________________________  - Cone 022

2350F                             2250F   2150F                                                                 1940F                        1830F                                                       Below 1700F

Cone 10                          Cone 5 & 6 Stoneware                                                      Greenware                 Low Fire Glazes                                       Real Gold
Stoneware                                                                                                                     turns to Bisque          Always use Medium                                Decals, Lustres
                                                                                                                                        Always use Slow                                                                           Glass Fusing


For Manual Kilns with a Kiln Sitter
For use in the Sitter

Boxes of 50 - prices are per box
Retail - $12.00 - Your price - $9.60
Bars - BRB - Cone 022 through Cone 10
Cones - SRB - Cone 022 through Cone 10

Self Supporting Shelf or Witness Cones
For use on the Kiln Shelf
Boxes of 25 - prices are per box
Retail - $12.00 - Your price - $9.60
Cones - SSB - Cone 022 through Cone 10

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American Ceramic Supply Company has been selling and servicing ceramic kilns to the ceramic industry, schools, individuals and studios for 40 years. Based in Fort Worth, Texas, American Ceramic Supply Company services and supplies ceramic equipment and supplies to traditional ceramic shops, paint your own pottery studios, ceramic potters, art teachers and art educators, ceramic and pottery finished ware producers, ceramic and pottery home based hobbyists. American Ceramic Supply Company provides education, training and consulting services to traditional ceramic shops, paint your own pottery studios, potters, art teachers and art educators, ceramic and pottery finished ware producers and home based hobbyists. American Ceramic Supply also educates and assists the architects, contractors, builders and electricians for our customers as they create their ceramic shops, paint your own pottery studios, ceramic rooms in their new schools and buildings and in their homes.

American Ceramic Supply Company and American Glass Supply Company sell ceramic kilns including Paragon Kilns, Skutt Kilns, Amaco/Excel Kilns, Cress Kilns and Olympic Kilns. Paragon’s Kilns include the Touch and Fire electric automatic kilns such as the TnF 82, TnF23, TnF24, TnF27 and TnF28’s, the Ovation kilns, Dragon and Super Dragon kilns, Iguana Kilns, Caldera and Clamshell Kilns, Janus kilns, as well as the small kilns such as the SC series kilns, heat treating kilns, doll and porcelain kilns. Skutt kilns include the Kiln Master kiln series - the popular KM818, KM1018, KM1027, KM1218, KM1227-3 and KM1231 kilns, the Glass Master kiln line such as the GM814, GM1014, GM1214 - the very popular GM1414 coffin kiln, and the production glass kiln line - the GM818, GM1018 and the GM1227-3 as well as the Skutt Hot Start Pro Kiln and the new Firebox kilns - Firebox 8 and Firebox 14 including the clamshell kiln GM22. Through American Ceramic Supply Company, Olympic Kilns has fantastic gas and glass kilns, raku kilns, electric - manual and automatic kilns such as the Dual Media Kilns, the Champ kiln, the Freedom Series kilns, the Commercial Electric kilns, and the Torchbearer Gas kilns- both available as propane or natural gas kilns. Olympic also has truck kilns, commercial industrial kilns, custom kilns, DPF Cleaning Kilns and industrial kilns. Amaco kilns and Excel Kilns are very popular kilns with teachers and art educators. Front loading kilns, top-loading kilns, professional kiln line series, Fine Art kilns, Professional Kiln series, and metal enameling kilns are all part of the Amaco kilns and Excel kilns production series. Whether you need a pottery kiln, jewelry kiln, silver art clay kiln, glass fusing kiln, glass slumping kiln, knife heat treating kiln, clay tile production kiln, low fire kiln, high fire kiln, 120V kiln, 240V kiln, 208V kiln or even a 480V kiln! -
American Ceramic Supply Company can provide you with just the kiln for your very special needs and desires to last you for a very long time!

American Ceramic Supply Company continues to sell, service, educate and provide on-going marketing and technical support to the ceramic and pottery industry. Our goals are the best customer service we can possibly offer, generosity of information to our customers so that they can succeed and accomplish their ceramic dreams and desires and
doing the right thing by God and Country.

American Ceramic Supply Company, Inc. - est. 1975
American Glass Supply Co.
The Pottery Consultant
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