Clogged threads are caused by poor drainage of a threaded section after the product is withdrawn from the galvanizing kettle. Clogged threads, as seen to the left, can be cleaned by using post-galvanizing cleaning operations such as a centrifuge or by heating them with a torch to approximately 500 F (260 C) and then brushing them off with a wire brush to remove the excess zinc. The clogged threads must be cleaned before the part will meet the specification.
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