DIN 338 - What does it mean?

DIN 338 is a standard set by the Deutsches Institut für Normung (DIN), the German Institute for Standardization, that specifies the dimensions and characteristics of twist drills (also known as twist drill bits). These are commonly used tools for drilling holes in a variety of materials including metal, wood, and plastic. Here’s what DIN 338 entails and why it’s important:

Key features of DIN 338


  ※Overall Length: Specifies the total length of the drill bit.

  ※Flute Length: Specifies the length of the helical flutes that remove material as the drill bit penetrates the workpiece.

  ※Diameter: Specifies the diameter of the drill bit, ensuring it meets specific tolerances for accuracy.

2.Types of Drill Bits:  

 DIN 338 covers parallel shank twist drills (also known as straight shank twist drills), which have a uniform diameter throughout the shank and cutting portion.

3.Helix Angle: 

 The standard defines the helix angle of the flutes, which affects the cutting action and the type of materials the drill is best suited for.

 Common types include:

  ※Type N: Normal helix, suitable for general-purpose drilling in materials like steel and iron.

  ※Type W: Higher helix angle for softer materials like aluminum and plastics.

  ※Type H: Lower helix angle for harder materials like stainless steel and cast iron.

4.Point Angle:

 Defines the angle of the drill bit tip, typically around 118 degrees for general-purpose bits. This angle can vary depending on the specific material and application.


 The standard specifies the types of materials the drill bits can be made from, such as high-speed steel (HSS) or other specialized alloys.


 DIN 338 may also specify surface coatings like black oxide, titanium nitride (TiN), or other coatings that enhance the durability and performance of the drill bits.


DIN 338 is a crucial standard for ensuring the quality, consistency, and performance of twist drills used across various industries. By adhering to this standard, manufacturers can produce reliable and efficient drill bits that meet the needs of professionals and hobbyists alike, while users can be confident in the tools they select for their drilling tasks. If you have any questions about it,pls feel free to contact us!

Post time: May-23-2024