CTM Potters Supplies - if you use clay you need CTM

Doncaster Tel: 01709 770801

Simba Materials Limited t/a

CTM Potters Supplies Co Reg No 05659119

   Doncaster Fax : 01709 770803

doncaster@ctmpotterssupplies.co.uk CTM Potters Supplies - Doncaster, Unit 8 Broomhouse Lane Industrial Estate, Edlington, Doncaster DN12 1EQ

Delivery charges and VAT will be added on to all orders. Prices on this website and in all downloads are net of VAT. Prices are subject to change without notice.

Exeter Tel: 01395 233077

   Exeter Fax : 01395 233905

admin@ctmpotterssupplies.co.uk CTM Potters Supplies - Exeter, Unit 10A Mill Park Industrial Estate, White Cross Road, Woodbury Salterton EX5 1EL

All prices are in GBP - often per kg - and need delivery and VAT to be added. For some items there are pictures or more information if you press on the link. You can order by email, phone, fax but but you cannot pay online - please see ORDERING

Please Note

Orton Pyrometric Cones

  • Standard Large Cones
  • OR Codes         6 cm tall
  • box of 50 £11.50+ VAT
  • bag of 10 £4.20 + VAT
  • we usually stock grades 017 to 012, 08 to 01 and 1 to 12
  • Small Cones
  • OSC Codes        3 cm tall
  • box of 50 £8.00 + VAT
  • bag of 10 £2.90 + VAT
  • we usually stock grades 017 to 015, 010 to 01 and 1 to 12
  • Mini Bars
  • OMB Codes     2.5 cm tall
  • box of 50 £8.40 + VAT
  • we usually stock grades 017 to 014, 08 to 01 and 1 to 12

It is always worth asking if we have a temperature grade as we do have some odd ones.


Please be clear in which size, grade and quantity you want.

Delivery Charges

For props, stilts, extension props, batts, shelves, tile cranks, bead firing stands, support, nichrome wire, t/couples, pyrometers, blankets, mortar etc - go to REFRACTORY/FIRING



We do strongly advise the use of pyrometers, controllers and thermocouples as they are much more accurate in their use. However, where you are unable to do so, or are needing to compare the relative difference in “heat work” in different areas of a kiln,

Orton Pyrometric Cones and Bars are a useful tool.

The cones and bars are made out of a refractory material designed to bend at different temperature ranges but based on the “heat work” that they have reached.


What this means is that the bending is a function of the “temperature reached” and of “the rate of increase in temperature” within the last 100oC of reaching the target temperature that particular cone has been designed to bend at.  


So for example a 05 cone bends at 1030oC at a rate of 60oC per hour, 1038oC at 100oC per hour, 1046oC at 150oC per hour or 1062oC at 300oC per hour.  But as it is a function of heat and time it will also bend if soaked - a 05 cone can bend at 1010oC if reached there very slowly and is then soaked for over an hour.


Once it starts to bend it can take 25-30 minutes to fully bend - it bends slowly at first - in the picture below the first cone started bending at 1250oC, second cone is 25 minutes later at 1277oC and the third cone is 6 minutes later at 1282oC so you can see the large difference in bend between the second and third cone is only 5oC ! - Cone 10 at 60oC phr.


Each grade is a slightly different colour for identification purposes and made in pairs - you need to split them before using them. They come as a box of 50 of one grade - for the Standard Large Cones and Small Cones we can sell in 10’s but not the Mini-Bars.

OR for Large

OSC for Small

OMB for Mini-Bars

Bending Temperature oC based on a "Rate of Increase at 60 oC per hr"

Bending Temperature oC based on a "Rate of Increase at 150 oC per hr"

Bending Temperature oC based on a "Rate of Increase at 300 oC per hr"

018

712

732

752

017

736

761

784

016

769

794

825

015

788

816

843

014

807

836

870

013

837

859

880

012

858

880

900

011

873

892

915

010

898

913

919

09

917

928

955

08

942

954

983

07

973

985

1008

06

995

1011

1023

05

1030

1046

1062

04

1060

1070

1098

03

1086

1101

1131

02

1101

1120

1148

01

1117

1137

1178

1

1136

1154

1184

2

1142

1162

1190

3

1152

1168

1196

4

1160

1181

1209

5

1184

1205

1221

6

1220

1241

1255

7

1237

1255

1264

8

1247

1269

1300

9

1257

1278

1317

10

1282

1303

1330

11

1293

1312

1336

12

1304

1324

1355

If you intend to use cones in a very fast firing kiln - 300oC per hour - please calcine the cones first - fire them up to 400oC

PRICE LIST

BROWSE - RING or EMAIL

We will price it up for you. Pay over the phone or you can do a bank transfer!