Chungjin / Gundrills
Deep hole gundrills
Resolving tool troubles through perfect tool engineering
Customised gundrills
Outer diameter range ø1.6 - 60 mm
Single flute, Double flute, Solid and step gundrills
PCD gundrills, Gunreamers
Amazing facts!
── Introducing ideas and technologies ──
Chungjin Engineering Co., Ltd. from South Korea is a professionally manufacturer of Gundrills and Gunreamers for 20 years since its establishment in 1993. Based on the technical skills accumulated in cutting tool manufacturing over the years, Chungjin have successfully developed their own technology to produce excellent products by incorporating them into the gundrill developed for processing holes in gun barrels with the aim of developing localisation.
Chungjin supplies tools to the domestic and overseas markets with the best quality and technology, and after starting exports, currently exporting to major markets such as Japan, China, and other Asian countries. Through endless product development and efforts, Chungjin obtained a certificate for their R&D department in 2012 to further devote themselves to product research and development, and as a result, succeeded in manufacturing the first PCD gundrill in South Korea and received the Vision Enterprise Certificate Award of the year.
Chungjin can customise gundrills from a minimum outer diameter of ø1.9 to a maximum outer diameter of ø60, and manufacture double flute, step gundrills, gun reamers, gundrill guide bushes, rest bushes, rubber bushes, brass bushes, etc. along with gundrills. In addition, Chungjin solves problems through tool engineering when tool troubles occur.
All employees of Cheongjin Machinery are promised to do their best to create the best service for customers, implement the best quality in the industry, and manage customer-centred company in accordance with the company’s management policy.
Specification
Single flute gundrills with brazed tungsten carbide tip
Sizes
DRILL Outside Diameter (ØD 0.005) [mm] | Carbide tip length (ℓ) [mm] | Total length (L) |
1.9~3.0 Less | 15 | As per order request |
3.1~5.0 Less | 20 | |
5.0~7.1 Less | 25 | |
7.0~10.0 Less | 30 | |
10.1~13.5 Less | 35 | |
13.6~16.5 Less | 40 | |
16.6~21 Less | 45 | |
21.1~25 Less | 50 | |
25.1~30 Less | 55 | |
30.1~60 | 60 |
DRIVER SIZE based on DRILL Outside Diameter (ØD) [mm] | DRIVER Outside Diameter (ØD) [mm] | DRIVER Inside Diameter (Ød) [mm] |
6.0 Less | 12.70 | 4.0 |
6.1~12 Less | 19.05 | 5.0 |
12.1~20 Less | 25.40 | 6.5 |
20.1~25 Less | 31.75 | 8.0 |
25.1 and over | 38.10 | 10.0 |
Tip shape
Tip shape | Outer | Inner | Work material |
Standard | 42 | 20 | Low carbon steel, |
30 | 20 | Carbon steel, |
Tip name
DRILL diameter (ØD) [mm] | Oil Clearance (G) [mm] |
3.5 | 0.7 |
7 | 1.1 |
9.5 | 1.3 |
13 | 1.6 |
16 | 1.8 |
19.0 | 2.4 |
22.0 | 2.6 |
25 | 2.7 |
Cutting condition
Work material | Ø2~6.5 mm | Ø6.5~13 mm | Ø13~19 mm | Ø19~25 mm | Ø25- mm | |||||
Cutting | Feed | Cutting | Feed | Cutting | Feed | Cutting | Feed | Cutting | Feed | |
Carbon | 60~70 | 0.010 | 70~80 | 0.020 | 80~90 | 0.025 | 80~90 | 0.030 | 80~90 | 0.035 |
Carbon | 50~60 | 0.007 | 60~70 | 0.015 | 70~80 | 0.020 | 70~80 | 0.025 | 70~80 | 0.030 |
Alloy steel | 60~70 | 0.010 | 70~80 | 0.020 | 80~90 | 0.025 | 80~90 | 0.030 | 80~90 | 0.035 |
Alloy steel | 50~60 | 0.017 | 60~70 | 0.015 | 70~80 | 0.020 | 70~80 | 0.025 | 70~80 | 0.030 |
Normal | 65~75 | 0.020 | 70~80 | 0.030 | 80~90 | 0.050 | 80~90 | 0.060 | 80~90 | 0.080 |
Ductile | 45~55 | 0.010 | 50~60 | 0.020 | 55~65 | 0.030 | 60~70 | 0.040 | 60~70 | 0.045 |
Aluminium | 100~150 | 0.020 | 100~160 | 0.030 | 140~180 | 0.050 | 140~180 | 0.060 | 140~180 | 0.080 |
Copper | 100~120 | 0.020 | 100~120 | 0.030 | 120~150 | 0.050 | 120~150 | 0.060 | 120~150 | 0.080 |
Cutting quality
Work material | Roughness of finished surface | Diameter expansion amount |
Steel (less than HB200) | ||
Steel (over HB200) | ||
Normal cast iron | ||
Aluminium alloy |
Gallery
Double flute gundrills with brazed tungsten carbide tip
Sizes
DRILL diameter (ØD) [mm] | Tip length | Total length |
6.0~7.5 Less | 15 | As per order request |
7.6~9.5 Less | 20 | |
9.6~12 Less | 25 | |
12.1~18 Less | 33 | |
18.1~22 Less | 40 | |
22.1~25 Less | 45 | |
25.1~ | 50 |
DRIVER SIZE based on DRILL | DRIVER | DRIVER |
6.0~12.0 Less | 19.5 | 5.0 |
12.0~20.0 Less | 25.40 | 6.5 |
20.0~25.0 Less | 31.75 | 8.5 |
25.0~30.0 Less | 38.10 |
※ The above table may be applied differently depending on the characteristics of the processed work material.
Cutting conditions
Work material | Ø6~8 mm | Ø8~13 mm | Ø13~19 mm | Ø19~25 mm | Ø25~ mm | |||||
Cutting | Feed | Cutting | Feed | Cutting | Feed | Cutting | Feed | Cutting | Feed | |
Normal | 55~75 | 0.050 | 60~80 | 0.060 | 70~90 | 0.080 | 70~90 | 0.120 | 80~100 | 0.150 |
Ductile | 45~60 | 0.040 | 55~70 | 0.060 | 60~80 | 0.060 | 60~80 | 0.080 | 65~85 | 0.100 |
Aluminium alloy | 100~150 | 0.050 | 120~160 | 0.080 | 150~180 | 0.080 | 150~180 | 0.120 | 150~180 | 0.150 |
Cutting quality
Work material | Roughness of finished surface | Diameter expansion amount |
Normal cast iron | ||
Ductile cast iron | ||
Aluminium alloy |
Gallery
Single flute gundrills with brazed tungsten carbide tip and chipbreaker
Sizes
DRILL |
Bit length |
Total length |
6.0~7.0 Less |
25 |
As per order request |
7.1~10.0 Less |
30 |
|
10.1~13.5 Less |
35 |
|
13.6~16.5 Less |
40 |
|
16.6~21 Less |
45 |
|
21.1~25 Less |
50 |
|
25.1~30 Less |
55 |
DRIVER SIZE based on DRILL Outside Diameter (ØD) [mm] | DRIVER Outside Diameter (ØD) [mm] | DRIVER Inside Diameter (Ød) [mm] |
6.0~12 Less | 19.05 | 5.0 |
12.1~20 Less | 25.40 | 6.5 |
20.1~25 Less | 31.75 | 8.0 |
25.1 Over | 38.10 | 10.0 |
Cutting condition
Gallery
Solid tungsten carbide monoblock gundrills
Made to order
Gallery
Step gundrills with brazed tungsten carbide tip
Made to order
Gallery
Gunreamers
Made to order
Gallery
Accessories
Guide bushes, rest bushes, brass bushes, etc.