Genuine OEM replacement part, this item is sold individually.
As the description says, this is the Steering Shaft for all of the Lawn Tractors shown below.
One of the most popular reasons this part is replaced, is that the gear on the shaft becomes worn or stripped.
It is advised that you check the part number 717-0622C Steering Gear Segment, before replacing the just the Steering Shaft.

Genuine Manufacturer Approved Carriage Bolt is a standard part that fits a variety of products. This part is sold individually and the Nut is not included. The square area under the head is designed to fit into a square hole in the work piece it measures 5/16-18 x .75. It is this square hole that restrains the bolt and keeps it from turning when the nut is tightened.

This is a genuine manufacturer-sourced replacement hardware that is commonly utilized on Craftsman lawn and garden equipment. A lock nut is a type of nut that resists loosening when it is properly threaded onto a bolt. This is a standard hardware which has multiple applications depending on your unit, make sure to check appropriate diagrams for correct location and use of this item. Please note this durable metal lock nut is sold individually.

This is a Genuine Manufacturer Approved replacement part used on a variety of Lawn Tractors. This part is Sold Individually. This item helps to secure Axle Assembly to the Pivot Axle. This also helps Axle to move freely and effortless. Due to constant use and pressure being put on this part it would need to be inspected periodically and replaced if its showing signs of wear.

This steering gear is an original part from Craftsman for lawn tractors. This piece is part of the tractors steering mechanism. This steering gear maneuvers the steering sector gear to move the lawn tractor wheels right or left. You will need a socket set to replace this part. This steering gear is made of metal and sold individually.

This cable is an original part from Craftsman for lawn tractors. This part pivots and pulls the belt idler pulley to fasten the belt and spins the cutting blades. It is recommended that you wear gloves before installing this part. You will need a pliers and a screw driver to replace this part. This cable is made of made of rubber, metal, and wire components.