Understanding the difference between rolled threads and cut threads?

This fastener characteristic can sometimes be confusing because the end results can be so similar. Knowing the difference can ensure you buy the right fastener for your specific application. 

To put it into the most simple terms, each process is basically explained within the title, “rolled thread” being when the metal rod is rolled to create threading and “cut thread” being the application when the metal rod is cut to create threading.

Understanding Rolled Threaded Fasteners

Rolled threaded fasteners are formed by cold forging blank metal rods at varying lengths between specific threaded dies. There are flat and rounded die plates for different applications. The threaded dies determine the pitch, length, Minor and Major diameter, and thread and Helix angle. As the blank rod is applied between the threaded dies it is pinched and rolled, this moves material into the desired threaded die holes some depressed and other expressed, leaving crest and root formation of a threaded fastener. At the end of the process the peak thread or crest will protrude from the pitch of the fastener because of the way the metal was pressed. The important characteristic of this process is that the material stays intact and is only manipulated to form the thread. This implies that this process maintains a more structurally sound product. Cold rolling fasteners allow for much larger quantities to be made at a time, it also costs much less than CNC cutting. 

POSITIVE

• Fast to manufacture
• Typically cheaper for bulk orders
• Requires minimal hands on
• Pre Cut die used to form thread making it more consistent
• Grain structure of metal isn't cut, it's reshaped making it stronger.
• Lighter 

NEGATIVE

• Can only work upto certain size rod
• Pitch and thread length is limited

Understanding Cut or Machine Threaded Fasteners

Cut threaded fasteners are created by tools or machines that have to manually engrave or cut out material from the blank metal rod in order to form the designed threading characteristics. Typically, these rods are attached to a tool that wraps around the rod using a metal tipped accessory to scrape away metal until desired shape is created.You can also cut the rods by programming the characteristics into a machine like a cnc machine to enable exact size and measurements to the thread. This process literally removes material from the rod digging grooves or threads little bits at a time. It can also be an issue because the naturally occurring grain of the metal is being interrupted and may cause chipping at high torques. Because the machine has to cut small amounts each pass, to avoid as much structural damage as possible, it takes longer than rolled threading. It also costs more due to the machinery and manpower required. However there are some benefits with cut threading like the ability to cut almost any size rod and create extremely large or small threading. The ability is endless. However, that's not a normal requirement, so as a common use process it is believed that rolled threading is more efficient. 

POSITIVE

• Can use with all shapes size rods
• Sharper grooves and edges
• Large threads or tiny pitch

NEGATIVE

• Cost more money
• Tooling will eventually wear out
• Not as structurally sound
• Requires additional manpower
• Takes longer due to multiple passes required.

In the end there are not many real life applications that would validate one process over the other. It more comes down to cost and time and how many fasteners you need made. Just know that no matter which you choose, if it's made from a reputable manufacturer, you'll be happy with the result!