지석(후렌지) - 발명특허(제 0951137호)
Patented (No. 0951137) Grinder (Flanges).
Patented Design for Mechanical Knife Sharpener (No. 0580337)
전동연마용 칼갈이 - 디자인특허(제 0580337호)
Design Patent for Grinding Stone (No. 0573072)
EPOXY지석 착수
Design Patent for Grinding Stone (No. 0573072)
숫돌 - 디자인특허(제 0573072호)