root4154 ^(^

대한민국 10대 걷기여행길을 소개합니다 http://v.media.daum.net/v/20160130094319266

여섯 청년의 특별한 나무 공방 이야기 http://media.daum.net/v/20140917144006853

ASTM, SAE AND ISO GRADE MARKINGS AND MECHANICAL PROPERTIES FOR STEEL FASTENERS Identification Grade Mark Specification Fastener Description Material Nominal Size Range (in.) Mechanical Properties Proof Load (psi) Yield Strength Min (psi) Tensile Strength Min (psi) No Grade Mark SAE J429 Grade 1 Bolts, Screws, Studs Low or Medium Carbon Steel 1/4 thru 1-1/2 33,000 36,000 60,000..