桥架这东西，外行看都长得像铁皮盒子，但一份合同写不写细节，直接决定这批货是“能用十年”还是“装完就返工”。

The bridge frame looks like an iron box to outsiders, but whether a contract specifies the details or not directly determines whether this batch of goods can be used for ten years or reworked after installation.

签单前把下面几条钉死，比砍单价有用：

Pin the following items before signing the order, which is more useful than cutting the unit price:

板材厚度按桥架宽度分档写，别只写“加厚”。宽度不超过150mm时侧板至少1.0mm，150到300mm至少1.2mm，300到500mm至少1.5mm，500mm以上至少2.0mm。到货用卡尺抽三点，标1.5实测1.1的，直接退。

The thickness of the board should be written according to the width of the bridge, not just "thickened". When the width does not exceed 150mm, the side panel should be at least 1.0mm, at least 1.2mm for 150 to 300mm, at least 1.5mm for 300 to 500mm, and at least 2.0mm for 500mm and above. Three points should be drawn with a caliper upon arrival, and if marked as 1.5 and measured as 1.1, it should be returned directly.

表面处理写工艺名+数值。热浸镀锌平均锌层≥65μm、局部不低于52μm；静电喷塑膜厚≥60μm。只写“镀锌处理”四个字，等于没约定。

Write the process name and numerical value for surface treatment. The average zinc layer of hot-dip galvanizing is ≥ 65 μ m, and locally it is not less than 52 μ m; The thickness of the electrostatic spray film is ≥ 60 μ m. Just writing the four words' galvanized treatment 'is equivalent to no agreement.

承载别信“承重强”这种形容词。让厂家标明SWL等级（A到D）和对应挠度——钢制满载挠度不超过跨距1/200。弯通、三通、伸缩节要和直段同材质同防腐，很多低价单在这里偷换薄板。

Don't believe in adjectives like 'strong load-bearing capacity'. Ask the manufacturer to indicate the SWL grade (A to D) and corresponding deflection - the steel full load deflection shall not exceed 1/200 of the span. Bent joints, tees, and expansion joints should be made of the same material and anti-corrosion as straight sections, and many low-priced orders are secretly replaced with thin plates here.

随货资料列清单：合格证、材质单、镀锌/盐雾报告、防火桥架的消防检测报告。缺一样，隐蔽验收时监理有权不让封板。

List of accompanying documents: certificate of conformity, material list, galvanizing/salt spray report, fire inspection report for fire-resistant bridge. If there is a missing item, the supervisor has the right not to allow the board to be sealed during concealed acceptance.

非常后加一句：大货和封样不一致按退货处理，误工按天扣。这一句比前面所有参数都管用。

Finally, add one sentence: If there is a discrepancy between the bulk and the sealed sample, it will be treated as a return, and any delay will be deducted on a daily basis. This sentence works better than all the previous parameters.

把“厚度分档、锌层写数、承载写等级、资料列清单”写进附件，桥架这摊采购才真正落了地。

Only by including the "thickness grading, zinc layer number, bearing grade, and data list" in the attachment, did the procurement of bridge frames truly come to fruition.