The kit includes four bolt lengths in 1/4"-20 thread: 1-1/2", 2", 2-1/2", and 3". Each length is paired with matching hex nuts, flat washers, and spring washers, totaling 192 pieces across all components.

All hardware in this kit is made from 304 stainless steel, which offers strong corrosion resistance, good tensile strength, and resistance to oxidation — suitable for both indoor and general outdoor applications.

All bolts in this kit use 1/4"-20 UNC (Unified National Coarse) thread, one of the most common thread standards in the SAE system. They are compatible with standard 1/4"-20 nuts, tapped holes, and threaded inserts.

Yes. 304 stainless steel provides good rust and oxidation resistance for general outdoor environments. For highly corrosive environments such as marine or coastal applications, 316 stainless steel is generally recommended.

Flat washers distribute the clamping load over a larger surface area to prevent damage to the workpiece. Spring washers (split lock washers) add tension to resist loosening from vibration. Using both together provides maximum holding security for the fastened joint.

This kit is suitable for machinery assembly, furniture hardware, electronic enclosures, household appliances, lighting fixtures, and general DIY fastening projects requiring 1/4"-20 hardware in lengths from 1-1/2" to 3".

The kit comes in a compartmentalized storage box with separate sections for each bolt length and hardware type, keeping all 192 pieces sorted and easy to access without mixing sizes together.