M35 Cobalt-Containing High Speed Steel Straight Shank Twist Drill 25PCs Set Twist Drill 1-13mm

 The structural characteristics of the hobbing drill and its impact on cutting processing

   (1The diameter of a twist drill is limited by the hole size, and the helical grooves make the drill core thinner, resulting in lower drill rigidity. There are only two flange bands for guidance, making it easy for the hole axis to deviate. The cross-cut edge makes centering difficult, leading to increased axial resistance and an increased risk of drill swaying. Therefore, the shape and position errors of the holes drilled are relatively large.

   (2）The front and rear cutting surfaces of a twist drill are both curved, and the lead and clearance angles at each point along the main cutting edge are unique. The lead angle of the side cutting edge can reach ...-55The cutting conditions are very poor; the distribution of cutting speed along the cutting edge is unreasonable, with the lowest strength of the knife tip having the largest cutting speed, leading to severe wear. Therefore, the precision of the processed hole is low.

   (3）The main cutting edge of the drill bit participates in the cutting process, and the cutting speeds at different points on the edge are not equal, which is easy to form helical chips and causes difficulty in chip removal. Therefore, the chips are squeezed and rubbed against the hole wall, often causing scratches on the hole wall, and the surface roughness after processing is very low.

 Maintenance and Care of Twisted Drills

  (1) When drilling steel parts, ensure sufficient cooling and use metal cutting fluid.

 (2) Good drill rod rigidity and guide gap can improve the accuracy of drilling and the life of the drill bit.

 (3) Please ensure that the magnetic chuck is flat and clean.

  (4) When drilling thin plates, it is necessary to reinforce the workpiece. When drilling large workpieces, please ensure the stability of the workpiece.

  (5) At the beginning and end of drilling, the feed rate should be reduced.1/3。

  (6) For materials that produce a large amount of fine powder when drilled, such as cast iron and cast copper, cooling liquid can be omitted and compressed air can be used to help remove the chips.

 (7) Please remove the iron chips wrapped around the drill body in time to ensure smooth chip discharge.