Straight Shank HSS Twist Drill Bits for Drilling Metal Iron and Aluminum

Advantage:

Wear resistance: precision grinding technology, strong wear resistance
Sharp head: sharp blade, special sharpening, fast drilling speed
Longer life: high hardness, durable use and long life
Smooth drilling: excellent material, higher drilling performance than ordinary drills

Precautions:

1. The life span of twist drills without coolant and coolant is between 5-20 times, depending on the actual operating environment.
2. The results of different speeds and human use will vary greatly
Theoretically: the slower the speed, the longer the life, but too slow will make it impossible to drill
3.The most important thing about the sharpness and wear resistance of twist drills is the geometric angle. Theoretically, twist drills are not exactly the same, but they are all slightly different, just like human beings.

The material has good toughness, wear resistance and strong drilling ability.
Commodity use: suitable for drilling and reaming of wood such as walnut, vajra, bodhi seed, buddha beads, etc., and also for drilling amber, iron, aluminum, plastic, etc.
The thinner drill bit should be used carefully when drilling holes, and use it slowly, so it is not easy to break!

Pay attention to the small details of the twist drill:
①: The cutting edge should be level with the grinding wheel surface. Before grinding the drill bit, the main cutting edge of the drill bit and the grinding wheel surface should be placed on a horizontal surface, that is to say, when the cutting edge contacts the grinding wheel surface, the entire edge must be ground.
②: The axis of the drill bit should be inclined at an angle of 60° with the surface of the grinding wheel. This angle is the front angle of the drill bit. The angle at this time is incorrect, which will directly affect the size of the top angle of the drill bit, the shape of the main cutting edge and the bevel angle of the chisel edge.
③: Grind backwards from the edge of the twist drill. That is, the cutting edge of the drill starts to contact the grinding wheel, and then slowly grinds down along the entire flank surface. , Also pay attention to the cooling of the drill bit, so that it can not be over-ground, causing the cutting edge to discolor, and even the cutting edge is annealed.
④: The cutting edge of the drill must swing up and down, and the tail of the drill must not be warped. The main cutting edge must swing up and down on the grinding wheel, that is, the hand holding the front of the drill bit must evenly swing the drill up and down on the grinding wheel surface. However, the hand holding the handle cannot swing, and the rear handle must not be tilted upwards, that is, the tail of the drill bit cannot be tilted higher than the horizontal center line of the grinding wheel, otherwise the cutting edge will be blunt and unable to cut.