1. Home
  2. /
  3. ITI Course
  4. /
  5. Drill parts Shank, flutes, tang, body, land, margin, web, body clearance, point and heel

Drill parts Shank, flutes, tang, body, land, margin, web, body clearance, point and heel

Friends, in today’s post, what are the parts of the drill or the parts of the drill. In what sizes it is available in the market, etc. have been told about it. If you want to get information about all these then read the post completely.

1.shank

This is the top part of the drill, this part of the drill is plane, in the drill machine this part is trapped or caught. And it is of following two types-

(i) straight shank

The part of this type of shank is parallel or cylindrical. This type of shank drill is used for small diameter drills.

(ii) Taper Shank

This shank has Morse paper, this type of shank is made in standard taper. The upper part of the taper shank is planeed from both the sides to form a tang. And a wedge shaped tool drift is used to take the taper shank drill out of the drill chuck.

2.tang

This part is in the taper shank drill, it is small and flat. This part only fits into the spindle of the drilling machine.

3.Flutes

These are a type of grooves, which are made in the body of the drill. And it removes shavings of metal or material when the drill is rotating. These are three or more in longer drills.

purpose of flutes

  1. The flute forms the cutting edge in the drill.
  2. There is a gap in the middle of the flute, where the coolant can easily reach the cutting edge, and the drill does not heat up, which increases the life of the drill.
  3. The shavings come out more easily through the flute, so longer drills tend to create more flutes.

4.Body

The part of the drill in which the flutes are cut, that part of the drill is called the body. This part is from the dad center to the neck. And this part has a slight taper (5mm to 100mm) from the dead center to the shank. Due to this taper, the body of the drill does not rub against the walls of the hole while drilling.

5.Land

The entire area between the flutes in a drill is called the land. And leaving some part of this land, the diameter of the rest is reduced a bit. This diameter is called the clearance diameter.

6.Margin

Above the land there is a fine spiral shaped raised line in the cutting shape, which is called margin. This margin is what forms the shape of the hole. And the distance between two opposite margins is the diameter of the drill. The width of this margin is kept from 1 mm to 2 mm depending on the size of the drill.

7.Body Clearance

The rest or remaining part of the land excluding the margin is called the body clearance. And the body does not friction with the clearance hole, as it has a smaller diameter, due to which the friction is reduced.

8.point

The front part of the drill, which is in the shape of a cone, is called a point. It is also called chisel edge or dad center.

9.heel

The part behind the cutting edge is called the heel. This part is taper at the back so that only the cutting edge touches the bottom of the job while cutting.

10.web

The middle of the body of the drill, which remains between the flutes built on it, is called the web. And its thickness increases from point to shank.

drill size

It has been described in four systems, which are described below-

1.Millimeter size drill

Drills of this size are described on the basis of the metric method. According to this method, drills up to 16 mm are of straight shank and drills larger than 16 mm are of taper shank. It is of two types-

(i)Straight Shank Drill

Drills up to 16 mm in size come in a straight shank. These are as follows-

S.No. Size interval
1. from 0.2 to 0.98 mm total 32 drills
2. from 1 to 3 mm 0.05 mm
3. from 3 to 14 mm 0.1 mm
4. from 14 to 16 mm 0.25 mm

(ii) Taper Shank Drill

Drills larger than 3 mm have a taper shank. Six types of Morse taper are provided in this type of drill shank. It is displayed from MT1 to MT6. These are of the following types.

No. no Size interval
1. from 3mm to 14mm 0.3 mm
2. from 14mm to 32mm 0.25 mm
3. 32mm to 51mm 0.5 mm
4. 52mm to 102mm 1 mm

Morse taper is found in large size drills. This Morse taper is self catching. Which are as follows-

S.No. drill size in mm morse taper number
1. from 3 to 14 1
2. 14.25 to 23 2
3. 23.50 to 31.50 3
4. 32 to 49.50 4
5. 50 to 76.50 5
6. 77 to 100 6

2.inch size drill

Also called a fractional size drill, there are drills of smaller sizes (up to 1/2″) of straight shanks and larger sizes of taper shanks. Which are as follows-

(i)Straight Shank Drill

These drills range in size from 1/64″ to 1/32″, and are available in 1/64″ spacing.

(ii) Taper Shank Drill

These drills range from 1/8″ to 5″ in diameter.

S.No. Size interval
1. 1/8″ to 2″ 1/64″
2. 2″ to 7/2″ 1/32
3. 7/2″ to 5 1/16″

3.Number Size Drills

According to this method drills are available in the markets from 1 to 80 numbers. Of these, the number 1 drill is the largest, measuring 0.228″ or 5.791 mm in diameter. And the number 80 drill is the smallest, with a diameter of 0.0135″ to 0.35 mm. Their full description is as follows-

S.No. inches mm
1. 0.228 5.791
2. 0.221 5.613
3. 0.213 5.410
4. 0.209 5.309
5. 0.2055 5.220
6. 0.204 5.182
7. 0.201 5.105
8. 0.199 5.055
9. 0.196 4.978
10. 0.1935 4.915
11. 0.191 4.851
12. 0.189 4.801
13. 0.185 4.699
14. 0.182 4.623
15. 0.180 4.572
16. 0.177 4.496
17. 0.173 4.394
18. 0.1695 4.305
19. 0.166 4.216
20. 0.161 4.216
21. 0.159 4.039
22. 0.157 3.988
23. 0.154 3.912
24. 0.152 3.861
25. 0.1495 3.797
26. 0.147 3.734
27. 0.144 3.658
28. 0.1405 3.569
29. 0.136 3.454
30. 0.1285 3.264
31. 0.120 3.048
32. 0.116 2.946
33. 0.113 2.870
34. 0.111 2.819
35. 0.110 2.794
36. 0.1064 2.705
37. 0.104 2.642
38. 0.1105 2.578
39. 0.0995 1.527
40. 0.098 1.489
41. 0.096 2.438
42. 0.0935 2.375
43. 0.089 2.261
44. 0.086 2.184
45. 0.082 2.083
46. 0.081 2.057
47. 0.0785 1.994
48. 0.076 1.930
49. 0.073 1.854
50. 0.070 1.778
51. 0.067 1.702
52. 0.0635 1.613
53. 0.0595 1.511
54. 0.055 1.395
55. 0.052 1.321
56. 0.0465 1.181
57. 0.043 1.092
58. 0.042 1.067
59. 0.041 1.041
60. 0.040 1.016
61. 0.0390 1.00
62. 0.0380 0.98
63. 0.0370 0.95
64. 0.0360 0.92
65. 0.0350 0.90
66. 0.033 0.85
67. 0.032 0.82
68. 0.031 0.79
69. 0.0292 0.75
70. 0.0280 0.70
71. 0.0260 0.65
72. 0.0240 0.65
73. 0.0240 0.60
74. 0.0225 0.58
75. 0.0210 0.52
76. 0.0200 0.50
77. 0.0180 0.45
78. 0.0160 0.40
79. 0.0145 0.38
80. 0.0135 0.35

4.Character Shaped Drills

They are displayed in English letters. The smallest drill is denoted by ‘A’, with a diameter of 0.234″ or 5.994 mm. And the largest drill is denoted by ‘Z’, which has a diameter of 0.413″ or 10.490 mm. their Complete The description is as follows-

Letter inches mm
A 0.234 5.944
B 0.238 6.045
C 0.242 6.147
D 0.246 6.248
E 0.250 6.35
F 0.257 6.528
G 0.261 6.629
H 0.266 6.756
I 0.272 6.909
J 0.277 7.036
K 0.281 7.137
L 0.290 7.366
M 0.295 7.493
N 0.302 7.671
O 0.316 8.026
P 0.323 8.204
Q 0.332 8.433
R 0.339 8.611
S 0.348 8.839
T 0.358 9.093
U 0.368 9.347
V 0.377 9.576
W 0.386 9.804
X 0.397 10.084
Y 0.404 10.262
Z 0.413 10.490

Friends, if you like this post then share it with your friends and join us Telegram Channel Join.

Read Also- about the drill

Read in Hindi: Drill parts Shank, flutes, tang, body, land, margin, web, body clearance, point and heel
in Hindi

Leave a Reply

Your email address will not be published.