3 Steps to Find Your Right Drills Bit Easily!

3 Steps to Find Your Right Drills Bit Easily!

Follow these 3 steps, you will find the right drill bits easily!
Before that, let's take a look at what a drill should look like. 
There are the following parts of a drill:

Drill Part
Body: The body between the shank and the point of the drill is called the body, which is fluted and relieved.

Point: The endpoint of the drill is called point and it is cone-shaped.
Different point angles are designed for different materials, this is the company's know-how.

Shank: It is the part that fits into the holding device.

Flutes: Spiral grooves on the body of the drill are called flutes, and their length is called "Flute Length"

Diameter: The diameter over the margins of a drill measured at the point.

Helix Angle: The angle is formed by the leading edge of the land with a plane containing the axis of a drill.

Margin: It's also known as a land. The length of the body across the body between the flutes. The surface of margin is part of a cylinder that is interrupted by the flutes and what is known as body clearance. This allows the drill to revolve without binding when drilling deep holes.

Body Clearance: The part of the body whose diameter is slightly less than the diameter of the drill is called body clearance, in order to reduce the friction between the drill and the walls of the hole being drilled, while the margin ensures the hole is with the accurate size.

Step 1: What is your processing method? 

1) Through
2) Blind
3) Flat Bottom
4) Chamfer
5) Step
6) Cross
7) Inclined Surface

Step 2: What is your processing material?

According to the specifications of ISO 513, the materials are classified into six common types according to the characteristics of the materials.
Groups Workpiece materials SPEED TIGER Related Products 
P  Low-alloy steel and cast steel
High-alloy steel and cast steel
e.g., S45C, 1045, CK45, 1.0503; SCM440, 4140, 42CrMo4.
PK / PKC Series
FD / FDC Series
M  Stainless steel (austenitic)
e.g., AISI 316, SUS316, 0Cr17Ni-12Mo2, SUS304, X5CrNi18-10, JIS SUS304L.
SN / SNC Series
K  Grey cast iron (GCI)
Ductile cast iron
Nodular cast iron (NCI)
PK / PKC Series
N  Non-ferrous metals:
Aluminum and aluminum alloys
e.g., A1070, A4032, A6061, A5052, A7075, AC, ADC, AlZnCu1.5
AL / ALC Series
- Titanium and titanium alloys
e.g., Ti6Al4V, Ti6Al2Sn4Zr2Mo, Ti4Al4Mo2Sn0.5Si, Ti10Al2Fe3Al, Ti5Al5V5Mo3Cr, Ti7Al4Mo
- Nickel / Inconel
e.g.,  Inconel 601, 617, 625, Incoly 800, Monel 400, Inconel 718, 718plus, Incoly 925, Waspalloy, Hastelloy, Rene.
SN / SNC Series for Titanium
H  Hardened steel
e.g., SKD61, SKD11, STAVAX, SKT, HPM1, S45C, 1045, 1.0503, C45; 4140, SCM440, 42CrMo4.
HD Series

Step 3: How to choose the size you exactly need?

The basic 3 elements of drilling:
  • ​1. The size of the hole
  • 2. Depth of the hole
  • 3. The accuracy of the hole
So, the last step is to select the most suitable drill bit based on these 3 elements.
  1. The size of the hole: You use metric? Or inch? Do you know the number of tap threads? Or forming tap? Then you will know the size you need to use.
  2. What’s your processing depth (=Depth of the hole)?3 times of the diameter? The maximum of Speed Tiger’s Drill Bits is 8 times.
  3. The accuracy of the hole: There are h6 ~ h13, and the tolerance class of Speed Tiger’s Drill Bits is h7.

Tips: With the correct coating on the tool, the machining effect will be multiplied with less effort!
The purposes of coating are:
✔️ Increase the hardness.
✔️ Increase lubricity.
✔️ Provide better chip evacuation.
✔️ Provide a thermal barrier.
✔️ Improve the surface finish.
✔️ Reduce abrasive wear.
✔️ Prolong the tool's life.

According to the characteristics of the workpiece material and the geometry of the drill bits, we select 5 types of coatings suitable for the drills. Let's take a look at the characteristics:

Item Coating Type ZrN-A nACo nACro TB
Characteristic Hardness (HV) ~3400 45 (Gpa) 42 (Gpa) >6000
Thickness (IJm) 2~4 2~4 2~4 <1
Oxidation Temp.(°C) 900 1200 1100 500
Friction Coefficient 0.3 0.35 0.35 <0.1
Color Golden Blue Gray Black
Carbon Steel X
High Speed Steel X
Stainless Steel X
Alloy X
Copper / Aluminum X X
Inconel X
Plastic / Composites/
Wood / Paper
Cutting Way Dry Cutting
Wet Cutting
Oil Spray

Too much information? 
No worries, we have already matched the drills and their coatings.
All you need to know is the material you want to process and the diameter and depth of the hole you need, and then you can choose the right drill bits from SPEED TIGER carbide drill bits series.

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About Speed Tiger

Speed Tiger is a professional manufacturer of Carbide Cutting Tools and offers OEM Services, having rich experience in producing carbide cutting tools and processing consultants for more than 24 years.
Speed Tiger Products Range

Established in 1998, Speed Tiger specialized in the production of precision carbide end mills, drills, turning tools, thread mills, and other tungsten carbide steel customized cutting tools. Speed Tiger crafts cutting tools at extreme nanometer precision +-2㎛ to the exact, enabling to achieve professional cutting quality.

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