What is the name of a black iron block with two holes?

Here are some possible examples, in which a black iron block with two holes can be called:

Connectors: If two or more parts are connected by iron blocks, they can be called connectors, connecting plates or connecting blocks.

Fixing parts: If iron blocks are used to fix or support other objects, they can be called fixing parts, fixing plates or supporting blocks.

Mounting seat: If iron blocks are used to install or fix equipment or components, they can be called mounting seats, mounting plates or mounting blocks.

Cushion: If iron blocks are used in mechanical structures to provide support or adjust height, they can be called cushion blocks, pads or adjustment blocks.

Other special-purpose parts: according to the specific application and industry, iron blocks may have specific names, such as "shock absorber bracket" and "axle bracket" in automobile manufacturing.

Please note that these are just some possible examples, and the actual names may vary according to the specific circumstances. If you can provide more information, such as the use of iron, industry or related context, I can give a more accurate answer.