Views of a damaged "High-Speed-Steel" bur =>7 photos

 In this essay, I will show only damaged HSS burs. In the next essay I will write how they can be repaired with some degree of skill & knowledge.

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 The edge of the teeth has been damaged beyond in being used again successfully. The corners have been totally worn away but can be repaired with little effort.

 

 The bur corners have been in contact with a metal that changes the shape of the cutting edges.

  Constant wearing of the edges of the teeth renders the cutting action to be unsafe & unusable. In this case, please select another same size of bur from your inventory.

  Your selected bur will cut into the metal with little effort, why is this? The teeth have been kept sharp and constantly ready for advanced gemstone setting.

  If the bur teeth have been chipped or worn, the results could be catastrophic.

 THIS IS THE EPITOME OF A TERRIBLY DAMAGED BUR. Observe the damaged teeth, sometimes a bur like this can't be successfully repaired.

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 In the next following tutorial essay, I MIGHT BE ABLE TO REPAIR THIS BUR, BUT IT CAN BE SAVED ONLY BY REDUCING THE OVERALL MILLIMETER SIZE (anything is possible with certain limitations).

 

Why is a "Stone Shaped, Setting Bur" needed?" =>18 photos.

 This photo is the epitome of a 4-claw engagement ring. The claws are thick and have good strength to hold a diamond securely (under normal conditions) for many decades. 

  This "156C"shaped cutting bur has teeth that are sharp but have one major problem.

 The teeth are too close together they just don't cut deep into the metal as the HSS (High Steel Steel) bur will do.

 This HSS bur was meant for two things and that is to 'CUT & CARVE' A SEAT DEEP INTO THE METAL.

 I used a 'bud shaped' bur to prepare an indentation into the top 30% of the claw before the HSS cutting has started.

   The teeth of this HSS are spaced well apart and justify the main reason why they are great in preparing to set this gemstone. 

While the bur is rotating, it is allowing the metal granules to be quickly ejected. With other closely knit bur teeth, this option does not work well.

  Many times, during preliminary stone setting very soft stones, such as an Emerald or Amethyst these stones need to be finished with a 'Cup Bur' (77B). 

 

 In this photo, you can see the bur teeth at the correct angle. The correct name for this bur is a "156C" The letter "C" signifies that this bur is made with Carbide Steel, the "life of this bur" depends upon how this bur is making contact with the metal of the claw.  

 

 These (Carbide, #77B burs) will round off the tips of the claws evenly. We are looking for perfection at all times.

   The angles of the gemstone MUST ALWAYS MATCH THE ANGLES OF THE BUR.

 There are no shortcuts to be used in this type of stone setting.

  For any (experienced) Diamond Setter) a full inventory of burs is imperative. My own inventory well exceeds 150 HSS burs of all sizes. This total does not include my "156C" burs.

 Here are 10 of my HSS burs; as you can see, these burs are constantly well-maintained and not touching other burs.

 The angles of the metal cutting bur must align with the stone at all times. If the interior claw angles do not meet the stone, then gem-setting problems will surely begin.

 In this photo, I used a bud shaped bur, as I just explained to prevent the rotating bur from ruining the claw.

 The bur MUST PREPARE A 'STONE SEAT' WITH THE CORRECT DIMENSIONS. 

  Here are just a few of my 156C burs that will be needed in setting these very small rubies.

 

 I always spread out the 4 claws, as I need to have greater access for my handpiece and bur.

 These HSS burs tend to be rather aggressive for some delicate claw settings. You need to decide which kind of bur is best for you.

  I ALWAYS KEEP MY 'UNUSED BURS' IN THEIR OWN PLASTIC CONTAINER AND WELL OILED. RUST IS THE CONSTANT ENEMY OF STEEL BURS.

 There are two sizes of bur angles. The first is the 45degree angle, and here is the most common 90degree angle.

 As all of us are working with the 90degree shaped stone, there is little need for the shallower size.

 Some setters will use the 'shallow shaped' bur to make a bearing cut. I personally shy away from this size, that is my preference.