Mechanical design engineers planning a drivetrain typically have a range of component options to choose from, and many decisions will boil down to the specific application. When it comes to creating optimal torque output, rotational speed and direction, few decisions are as important in designing high performing gear drives as choosing the right gear for the job. 

With so many products, applications and requirements out there, several different gear types have been developed to handle specific jobs correctly. For most basic and common applications of gears sets, the options are most often focused on two specific types, which we’ll contrast here: spur gears vs. helical gears.

7 Factors to Consider in Choosing a Straight Cut Spur Gear or Helical Gear

We can’t hope to cover every scenario or evaluate how different configurations may weigh into a choice between a helical gear and a spur gear in this article. Focusing on some of the most general requirements will help guide a decision; we’ll make comparisons between these two gear options on these seven general performance considerations:  

Power transmission efficiency - the amount of speed to be transferred without waste or producing added forces

Load bearing capacity - the torque production and accommodation between the drive shaft and reduction gears

Speed handling - byproduct of efficiency and load bearing capacity, speed of movement the gear can handle

Durability requirement - expected lifetime of the gear, bending strength, scoring resistance and surface durability

Vibration & noise limits - the level gear mesh smoothness required in the final product

Cost to manufacture & maintain - the complexity to produce the gear and their relative availability

Capabilities - the mechanical function of the gear in relation to the gear set