This is a high-quality Hex Button Head Socket Cap Bolt Assortment Kit. Hex bolts are commonly used in furniture, cabinets, machinery, appliances, and many other applications. These bolts will not rust, corrode, or stain. The length of the bolts is measured from the top of the head to the end of the bolt. The head of the bolt has a hexagonal shape which provides a larger surface area for gripping with tools. These bolts are available in different lengths and sizes. Please check the description for the sizes and lengths available for this kit. The kit includes a wide variety of bolts in different sizes, so you will always have the right bolt for the job.