Types of Braze Joints

Butt Joint

Lap Joints

Butt-Lap Joint

Different types of joints can be created by joining two similar or dissimilar metals. Irrespective of the fact that there can be a variety of joints depending upon the style of joining, functions and assembly geometry, most of them are variety of two basic joints types that are Butt Joint and Lap Joint.

Butt Joint
When two metals are positioned in a head-to-head arrangement for brazing, it will result in a Butt joint. It provides the benefits of a single and consistent thickness at the joint. The preparation of this type of joint is very simple, while the proper result of butt joint are extra strong and possess sufficient tensile strength to serve different application.


A properly bonded butt joint is strong enough and have sufficient tensile strength to meet different application needs. The preparation of this type of joint is simple. The only drawback with butt joint is that the bonding area cannot be larger than the cross-section of the thinner member.


Lap Joints
Lap joint is the type of joint that have a larger surface area because it is formed by overlapping of two metals. This type of joint is preferred to those applications which require comparatively stronger bonds. It offers double thickness at the joining area. Due to overlapping, it helps in the maintenance of a uniform joint clearance mainly in tubular joints.


Usually the lap joint is self-supporting during the brazing process. As one flat member resides on the other, it helps to maintain a uniform joint clearance particularly in tubular joints, where nesting one tube inside the other holds them in proper alignment for brazing.


Butt-Lap Joint
It is a combination of both butt and lap type of joint and offers the advantages of both. Butt-lap joint give the profitable features of single thickness as well as of maximum strength. Self supporting in nature, butt-lap joint requires more work to assemble.



Advantages of a Brazed Joint

• A properly brazed joint is very strong joint and is usually stronger than the metals being joined.
  
  
• Generally, the brazed joints are made at relatively low temperatures which usually lies between 1150°F to 1600°F (620°C to 870°'C). The most important thing is that the base metals are not melted and thus, they can typically retain most of their physical properties.
  
  
• So you can select whatever metals you want to join, irrespective of the temperature difference between their melting point.
  
  
• Joints made by brazing seems good in appearance. These joints are neat and clean and have no comparison to the welded joints.