M-340S

M-340 with 0,25% added 60-80 mesh granular manganese. Has the same plastic and drying properties as M-340. The added manganese produces a fine black fired speck that usually bleeds up through glazes. Contains manganese so, a kiln vent should be used during the firing. 

Characteristics:
Cone: 5
Wet Color: Grey
Fire Color
                Oxidation: Light Buff
Texture: Very Slightly Coarse
Average Shrinkage
                Oxidation Cone 4: 4,0-5,0%
                                  Cone 7: 5,5-6,5%
Average Water Absorption
                Oxidation Cone 4: 4,0-5,5%
                                 Cone 7: 1,0-2,0%
COE x 10-6: N/A

* Protect from freezing.