248 GB/T 1098-1979 半圆键 键和键槽的剖面尺寸 Semi-circular (Woodruff) keys--Dimensions of cross sections and keyways
249 GB/T 1099-1979 半圆键 型式尺寸 Woodruff keys--Types and dimensions
250 GB/T 1144-1987 矩形花键尺寸、公差和检验 Straight-sided spline—Dimensions tolerances and verification
251 GB/T 1168-1976 螺柱技术条件 Studs--Technical requirements
252 GB/T 1228-1991 钢结构用高强度大六角头螺栓 High strength bolts with large hexagon head for steel structures 253 GB/T 1229-1991 钢结构用高强度大六角螺母 High strength large hexagon nuts for steel structures
254 GB/T 1230-1991 钢结构用高强度垫圈 High strength plain washers for steel structures
255 GB/T 1231-1991 钢结构用高强度大六角头螺拴、大六角螺母、垫圈技术条件 Specifications of high strength bolts with large hexa-gon head, large hexagon nuts, plain washers for steel structures
256 GB/T 1237-1988 紧固件的标记方法 Designation system for fasteners
257 GB/T 1337-1988 六角自锁螺母 Self-locking nuts,hexagon
258 GB/T 1338-1988 小六角扁自锁螺母 Self-locking nuts,reduced hexagon oblate
259 GB/T 1339-1988 小六角自锁螺母 Self-locking nuts,reduced hexagon
260 GB/T 1340-1988 成组游动托板自锁螺母支架 Supports for self-locking nuts,anchor floating,Gang channel
261 GB/T 1356-1988 淅开线圆柱齿轮 基本齿廓 Basic rack tooth profile of involute cylindrical gears
262 GB/T 1357-1987 渐开线圆柱齿轮模数 Modules of involute cyindrical gears
263 GB/T 1563-1979 楔键 键和键槽的剖面尺寸 Taper keys--Cross section dimensions of keys and keyways
264 GB/T 1564-1979 普通楔键 型式尺寸 Taper keys for general use--Types and dimensions
265 GB/T 1565-1979 钩头楔键 型式尺寸 Gib-head taper keys--Types and dimensions 266 GB/T 1566-1979 薄型平键 键和键槽的剖面尺寸 Thin flat keys--Cross section dimensions and keyways