What is the finish of the rack mount screws and what is its purpose?

The rack mount screws have a nickel-plated finish to prevent rust.

What is the thread type of the screws included in this pack?

The screws included in this pack are 10-32 thread type.

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StarTech.com CABSCRWS1032 Server Rack Screws - 50 Pack - 10-32 Screws - Rack Mount Screws - Network Rack Screws - Rack Mount Hardware

Mount server, telecom and A/V equipment with these high quality rack mount screws
Nickel-plated finish to prevent rack mounting screws from rust
Works with rack mount hardware like your server network or audio/video equipment
50 x 10 32 screws included / Server rack screws / 10-32 screws / Network Rack Screws / Cabinet mounting screws / 10 32 mounting screws / 10 32 thread / Rackmount chassis / Rack mount equipment