What is a "Black" Bolt?

The vast majority of bolts that Portland Bolt provides are either hot-dip galvanized or plain steel with no coating. In the construction fasteners industry, we typically refer to the plain steel as “black.” On our quotes and orders at Portland Bolt, we abbreviate that to “blk”. Other companies may refer to bolts with no coating as “bare”, “plain”, or “plain finish.”

The picture below from one of our quotes that says “blk” is short for “black” and is simply referring to a bolt with no coating.

Occasionally, there is some confusion as to what a black bolt means. There are some plating options such as black oxide or black zinc that provide an unmistakably black finish, but in the construction fastener industry, it’s relatively infrequent that those coatings are used. In the event that we are quoting either of those options, it would be made clear on our paperwork. See example below:

Of course, you can ask any of our sales representatives if there are any questions regarding the finish on the bolts you are being quoted or ordering.

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    Do you know what finish a GM bolt would have if it is described as:
    “xxxxxx (part number) 280M” ?

    thank you!

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