A na-atụba onye na-abaghị uru na alkali phenolic resin sand ma ọ bụ sodium silicate-bonded san process.Surface hardness esịmde kacha nta HRC48-58 na hardness omimi n'etiti 4-6mm (HRC45), mgbe okpomọkụ ọgwụgwọ usoro. The idler nwere ike idi elu mmetụta na-eyi. mgbochi n'okpuru ọnọdụ ọrụ siri ike.