Welcome To Our Website. Any questions about PCD cutting, brazing and grinding, Call Us:+86 17700605088

The Difference Between Ra and Rz

2020-10-19 11:29:32

 

 

The methodology of measurement and what is measured when calculating Ra and Rz are quite different. This is critical to understand if you will not be paid for your parts because the Ra you measured is not in fact the Rz surface profile that customer specified.

 

What is Ra?

What is Ra

 

Ra is calculated by an algorithm that measures the average length between the peaks and valleys and the deviation from the mean line on the entire surface within the sampling length. 

 

Ra averages all peaks and valleys of the roughness profile and then neutralizes the few outlying points so that the extreme points have no significant impact on the final results.

 

What is Rz?

What is Rz

 

“Rz is calculated by measuring the vertical distance from the highest peak to the lowest valley within five sampling lengths, then averaging these distances. Rz averages only the five highest peaks and the five deepest valleys—therefore, extremes have a much greater influence on the final value.”

 

Ra is the arithmetical average value of all absolute distances of the roughness profile from the center line within the measuring length.

 

Rz is the average maximum peak to valley of five consecutive sampling lengths within the measuring length. 

 

Ra averages all measurements and does not have any discriminating value in separating rejects from acceptable cylinders.”

 

When you want the better surface roughness of your parts, please feel free to contact More Super Hard, our experienced sales engineer will service for you.



  • Exhibits Recommand-A&G EXPO 2023
    19 September 2023

    Exhibits Recommand-A&G EXPO 2023

    A&G EXPO features abrasives, superhard materials and products, covering the latest technologies and products in the entire grinding industry chain, and providing grinding solutions.The 6th A&G EXPO will be held In Zhengzhou, Henan at September 20th to 22nd.Moresuperhard also participate A&G EXPO2023.

  • Case Sharing-Grinding and Regrinding  MCD Cutting Tools
    15 September 2023

    Case Sharing-Grinding and Regrinding MCD Cutting Tools

    Moresuperhard provide grinding and regrinding solution for MCD cutting tools.Today Moresuperhard share regrinding solutions of mcd cutting tools for Cellulose Acetate Eyeglass Frames.Moresuperhard provide cnc grinding machine and vitrified diamond grinding wheel for mcd cutting tools.

  Add:  Zhongyuan Rd, Zhongyuan District, Zhengzhou, 450001, Henan, China

  Tel: +86 17700605088

  WhatsApp:+86 17700605088

  E-mail: pcd@moresuperhard.com