What is TPI?


Examples of mechanical elements with a pitch:
- Screws / Threads.
- Knurls..
- Saw blades.
- Milling Cutters.
TPI Conversion Calculator
TPI conververtion formulas

\( \large TPI = \LARGE \frac {1}{P} \large \text { (P in Inches)} \)
\( \large TPI = \LARGE \frac {25.4}{P} \large \text { (P in mm)} \)
\( \large P = \LARGE \frac {1}{TPI} \large \text { (P in Inches)} \)
\( \large P = \LARGE \frac {25.4}{TPI} \large \text { (P in mm)} \)
\( \large TPI = \LARGE \frac {25.4}{P} \large \text { (P in mm)} \)
\( \large P = \LARGE \frac {1}{TPI} \large \text { (P in Inches)} \)
\( \large P = \LARGE \frac {25.4}{TPI} \large \text { (P in mm)} \)
TPI Convertion Chart
TPI | Pitch (Inch) | Pitch (mm) |
---|---|---|
2 | 0.5000 | 12.70 |
3 | 0.3333 | 8.47 |
4 | 0.2500 | 6.35 |
5 | 0.2000 | 5.08 |
6 | 0.1667 | 4.23 |
7 | 0.1429 | 3.63 |
8 | 0.1250 | 3.18 |
9 | 0.1111 | 2.82 |
10 | 0.1000 | 2.54 |
11 | 0.0909 | 2.31 |
12 | 0.0833 | 2.12 |
13 | 0.0769 | 1.95 |
14 | 0.0714 | 1.81 |
15 | 0.0667 | 1.69 |
16 | 0.0625 | 1.59 |
17 | 0.0588 | 1.49 |
18 | 0.0556 | 1.41 |
19 | 0.0526 | 1.34 |
20 | 0.0500 | 1.27 |
21 | 0.0476 | 1.21 |
22 | 0.0455 | 1.15 |
23 | 0.0435 | 1.10 |
24 | 0.0417 | 1.06 |
25 | 0.0400 | 1.02 |
26 | 0.0385 | 0.98 |
27 | 0.0370 | 0.94 |
28 | 0.0357 | 0.91 |
29 | 0.0345 | 0.88 |
30 | 0.0333 | 0.85 |
31 | 0.0323 | 0.82 |
32 | 0.0313 | 0.79 |
33 | 0.0303 | 0.77 |
34 | 0.0294 | 0.75 |
35 | 0.0286 | 0.73 |
36 | 0.0278 | 0.71 |
37 | 0.0270 | 0.69 |
38 | 0.0263 | 0.67 |
39 | 0.0256 | 0.65 |
40 | 0.0250 | 0.64 |
41 | 0.0244 | 0.62 |
42 | 0.0238 | 0.60 |
43 | 0.0233 | 0.59 |
44 | 0.0227 | 0.58 |
45 | 0.0222 | 0.56 |
46 | 0.0217 | 0.55 |
47 | 0.0213 | 0.54 |
48 | 0.0208 | 0.53 |
49 | 0.0204 | 0.52 |
50 | 0.0200 | 0.51 |
51 | 0.0196 | 0.50 |
52 | 0.0192 | 0.49 |
53 | 0.0189 | 0.48 |
54 | 0.0185 | 0.47 |
55 | 0.0182 | 0.46 |
56 | 0.0179 | 0.45 |
57 | 0.0175 | 0.45 |
58 | 0.0172 | 0.44 |
59 | 0.0169 | 0.43 |
60 | 0.0167 | 0.42 |
61 | 0.0164 | 0.42 |
62 | 0.0161 | 0.41 |
63 | 0.0159 | 0.40 |
64 | 0.0156 | 0.40 |
65 | 0.0154 | 0.39 |
66 | 0.0152 | 0.38 |
67 | 0.0149 | 0.38 |
68 | 0.0147 | 0.37 |
69 | 0.0145 | 0.37 |
70 | 0.0143 | 0.36 |
71 | 0.0141 | 0.36 |
72 | 0.0139 | 0.35 |
73 | 0.0137 | 0.35 |
74 | 0.0135 | 0.34 |
75 | 0.0133 | 0.34 |
76 | 0.0132 | 0.33 |
77 | 0.0130 | 0.33 |
78 | 0.0128 | 0.33 |
79 | 0.0127 | 0.32 |
80 | 0.0125 | 0.32 |
81 | 0.0123 | 0.31 |
82 | 0.0122 | 0.31 |
83 | 0.0120 | 0.31 |
84 | 0.0119 | 0.30 |
85 | 0.0118 | 0.30 |
86 | 0.0116 | 0.30 |
87 | 0.0115 | 0.29 |
88 | 0.0114 | 0.29 |
89 | 0.0112 | 0.29 |
90 | 0.0111 | 0.28 |
91 | 0.0110 | 0.28 |
92 | 0.0109 | 0.28 |
93 | 0.0108 | 0.27 |
94 | 0.0106 | 0.27 |
95 | 0.0105 | 0.27 |
96 | 0.0104 | 0.26 |
97 | 0.0103 | 0.26 |
98 | 0.0102 | 0.26 |
99 | 0.0101 | 0.26 |
100 | 0.0100 | 0.25 |
101 | 0.0099 | 0.25 |
102 | 0.0098 | 0.25 |
103 | 0.0097 | 0.25 |
104 | 0.0096 | 0.24 |
105 | 0.0095 | 0.24 |
106 | 0.0094 | 0.24 |
107 | 0.0093 | 0.24 |
108 | 0.0093 | 0.24 |
109 | 0.0092 | 0.23 |
110 | 0.0091 | 0.23 |
111 | 0.0090 | 0.23 |
112 | 0.0089 | 0.23 |
113 | 0.0088 | 0.22 |
114 | 0.0088 | 0.22 |
115 | 0.0087 | 0.22 |
116 | 0.0086 | 0.22 |
117 | 0.0085 | 0.22 |
118 | 0.0085 | 0.22 |
119 | 0.0084 | 0.21 |
120 | 0.0083 | 0.21 |
121 | 0.0083 | 0.21 |
122 | 0.0082 | 0.21 |
123 | 0.0081 | 0.21 |
124 | 0.0081 | 0.20 |
125 | 0.0080 | 0.20 |
126 | 0.0079 | 0.20 |
127 | 0.0079 | 0.20 |