Home / Standards / GB/T 17889.4-2012 GB/T 17889.4-2012 Abolished Ladders - Part 4: Single or multiple hinge-joint ladders 梯子 第4部分：带有单个或多个铰链的梯子 Standard Type GBT ICS N/A CCS J09 Status Abolished Issue Date 2012-05-11 Implementation 2012-12-01 Centralized Committee 国家标准委 Issuing Authority 国家标准委