Choose the Right Spur Gear Cutter, Every Time
Involute & Module Involute Cutters, 14-1/2° and 20° Pressure Angles — All In One Place
Use this guide to determine the right spur gear cutter for your application. You only need three numbers: the diametrical pitch (or module, for metric gears), the pressure angle, and the total number of teeth on the gear. Then follow the five steps below to find your Travers item number.
You’ll get:
- Cutter number ranges by number of teeth
- 14-1/2° and 20° involute (standard) cutter item numbers
- 14-1/2° and 20° module involute (metric) cutter item numbers
- Cutter diameter and hole size for every pitch and module
What you need before you start
- Diametrical pitch (for metric gears, this is the module)
- Pressure angle (14-1/2° or 20° for most gears)
- Total number of teeth on the gear
How to select your spur gear cutter in 5 steps
- Step 1: Use the range charts below to find the cutter number based on the number of teeth on your gear.
- Step 2: Find the chart that matches your gear: 14-1/2° or 20° pressure angle, and involute (standard) or module involute (metric).
- Step 3: In the first column of that chart, find the diametrical pitch (or module) of the gear you are making.
- Step 4: On the top row, find the cutter number from Step 1.
- Step 5: Look to the right of your pitch and below your cutter number to find the Travers item number.
Step 1: Find your cutter number
Involute gear cutters
Range of cutters by number of teeth on the gear
| Cutter # | # of teeth of gear |
|---|---|
| 1 | 135 teeth to rack |
| 2 | 55 to 134 teeth |
| 3 | 35 to 54 teeth |
| 4 | 26 to 34 teeth |
| 5 | 21 to 25 teeth |
| 6 | 17 to 20 teeth |
| 7 | 14 to 16 teeth |
| 8 | 12 to 13 teeth |
Specify cutter # and pitch when ordering.
Involute module gear cutters (metric): module marking guide
Module cutters are marked two ways: TTC standard markings and industry standard markings.
| TTC standard: cutter # | TTC standard: # of teeth | Industry standard: cutter # | Industry standard: # of teeth |
|---|---|---|---|
| 1 | 135 teeth to rack | 1 | 12 to 13 teeth |
| 2 | 55 to 134 teeth | 2 | 14 to 16 teeth |
| 3 | 35 to 54 teeth | 3 | 17 to 20 teeth |
| 4 | 26 to 34 teeth | 4 | 21 to 25 teeth |
| 5 | 21 to 25 teeth | 5 | 26 to 34 teeth |
| 6 | 17 to 20 teeth | 6 | 35 to 54 teeth |
| 7 | 14 to 16 teeth | 7 | 55 to 134 teeth |
| 8 | 12 to 13 teeth | 8 | 135 teeth to rack |
Steps 2–5: Find your Travers item number
Pick the chart that matches your gear. Items in each chart are listed by diametrical pitch (or module) down the left side and cutter number across the top.
14-1/2° pressure angle involute (standard) spur gears
Involute gear cutters (E18)
| Diametrical Pitch | Cutter Diameter (in.) | Hole Size (in.) | Cutter #1 | Cutter #2 | Cutter #3 | Cutter #4 | Cutter #5 | Cutter #6 | Cutter #7 | Cutter #8 |
|---|---|---|---|---|---|---|---|---|---|---|
| 2* | 5-3/4 | 1-1/2 | 10-281-020 | 10-282-020 | 10-283-020 | 10-284-020 | 10-285-020 | 10-286-020 | 10-287-020 | 10-288-020 |
| 2-1/2* | 5-3/4 | 1-1/2 | 10-281-025 | 10-282-025 | 10-283-025 | 10-284-025 | 10-285-025 | 10-286-025 | 10-287-025 | 10-288-025 |
| 3* | 5-1/4 | 1-1/4 | 10-281-030 | 10-282-030 | 10-283-030 | 10-284-030 | 10-285-030 | 10-286-030 | 10-287-030 | 10-288-030 |
| 4 | 4-1/4 | 1-1/4 | 10-281-040 | 10-282-040 | 10-283-040 | 10-284-040 | 10-285-040 | 10-286-040 | 10-287-040 | 10-288-040 |
| 5 | 3-5/8 | 1-1/4 | 10-281-050 | 10-282-050 | 10-283-050 | 10-284-050 | 10-285-050 | 10-286-050 | 10-287-050 | 10-288-050 |
| 6 | 3-1/2 | 1-1/4 | 10-281-060 | 10-282-060 | 10-283-060 | 10-284-060 | 10-285-060 | 10-286-060 | 10-287-060 | 10-288-060 |
| 7* | 2-7/8 | 1 | 10-281-070 | 10-282-070 | 10-283-070 | 10-284-070 | 10-285-070 | 10-286-070 | 10-287-070 | 10-288-070 |
| 8 | 2-7/8 | 1 | 10-281-080 | 10-282-080 | 10-283-080 | 10-284-080 | 10-285-080 | 10-286-080 | 10-287-080 | 10-288-080 |
| 9* | 2-3/4 | 1 | 10-281-090 | 10-282-090 | 10-283-090 | 10-284-090 | 10-285-090 | 10-286-090 | 10-287-090 | 10-288-090 |
| 10 | 2-3/4 | 1 | 10-281-100 | 10-282-100 | 10-283-100 | 10-284-100 | 10-285-100 | 10-286-100 | 10-287-100 | 10-288-100 |
| 11* | 2-3/8 | 1 | 10-281-110 | 10-282-110 | 10-283-110 | 10-284-110 | 10-285-110 | 10-286-110 | 10-287-110 | 10-288-110 |
| 12 | 2-5/8 | 1 | 10-281-120 | 10-282-120 | 10-283-120 | 10-284-120 | 10-285-120 | 10-286-120 | 10-287-120 | 10-288-120 |
| 14 | 2-1/2 | 1 | 10-281-140 | 10-282-140 | 10-283-140 | 10-284-140 | 10-285-140 | 10-286-140 | 10-287-140 | 10-288-140 |
| 16 | 2-1/2 | 1 | 10-281-160 | 10-282-160 | 10-283-160 | 10-284-160 | 10-285-160 | 10-286-160 | 10-287-160 | 10-288-160 |
| 18 | 2-3/8 | 1 | 10-281-180 | 10-282-180 | 10-283-180 | 10-284-180 | 10-285-180 | 10-286-180 | 10-287-180 | 10-288-180 |
| 20 | 2-3/8 | 1 | 10-281-200 | 10-282-200 | 10-283-200 | 10-284-200 | 10-285-200 | 10-286-200 | 10-287-200 | 10-288-200 |
| 22* | 2 | 7/8 | 10-281-220 | 10-282-220 | 10-283-220 | 10-284-220 | 10-285-220 | 10-286-220 | 10-287-220 | 10-288-220 |
| 24* | 1-3/4 | 7/8 | 10-281-240 | 10-282-240 | 10-283-240 | 10-284-240 | 10-285-240 | 10-286-240 | 10-287-240 | 10-288-240 |
| 26* | 1-3/4 | 7/8 | 10-281-260 | 10-282-260 | 10-283-260 | 10-284-260 | 10-285-260 | 10-286-260 | 10-287-260 | 10-288-260 |
| 28* | 1-3/4 | 7/8 | 10-281-280 | 10-282-280 | 10-283-280 | 10-284-280 | 10-285-280 | 10-286-280 | 10-287-280 | 10-288-280 |
| 30* | 1-3/4 | 7/8 | 10-281-300 | 10-282-300 | 10-283-300 | 10-284-300 | 10-285-300 | 10-286-300 | 10-287-300 | 10-288-300 |
| 32 | 2-1/4 | 1 | 10-281-320 | 10-282-320 | 10-283-320 | 10-284-320 | 10-285-320 | 10-286-320 | 10-287-320 | 10-288-320 |
| 48 | 1-3/4 | 7/8 | 10-281-480 | 10-282-480 | 10-283-480 | 10-284-480 | 10-285-480 | 10-286-480 | 10-287-480 | 10-288-480 |
*Special sizes
20° pressure angle involute (standard) spur gears
Involute gear cutters (E188)
| Diametrical Pitch | Cutter Diameter (in.) | Hole Size (in.) | Cutter #1 | Cutter #2 | Cutter #3 | Cutter #4 | Cutter #5 | Cutter #6 | Cutter #7 | Cutter #8 |
|---|---|---|---|---|---|---|---|---|---|---|
| 4 | 3-5/8 | 1-1/4 | 10-289-041 | 10-289-042 | 10-289-043 | 10-289-044 | 10-289-045 | 10-289-046 | 10-289-047 | 10-289-048 |
| 5 | 3-3/4 | 1-1/4 | 10-289-051 | 10-289-052 | 10-289-053 | 10-289-054 | 10-289-055 | 10-289-056 | 10-289-057 | 10-289-058 |
| 6 | 3-1/2 | 1-1/4 | 10-289-061 | 10-289-062 | 10-289-063 | 10-289-064 | 10-289-065 | 10-289-066 | 10-289-067 | 10-289-068 |
| 7 | 2-7/8 | 1 | 10-289-071 | 10-289-072 | 10-289-073 | 10-289-074 | 10-289-075 | 10-289-076 | 10-289-077 | 10-289-078 |
| 8 | 2-7/8 | 1 | 10-289-081 | 10-289-082 | 10-289-083 | 10-289-084 | 10-289-085 | 10-289-086 | 10-289-087 | 10-289-088 |
| 9 | 2-3/4 | 1 | 10-289-091 | 10-289-092 | 10-289-093 | 10-289-094 | 10-289-095 | 10-289-096 | 10-289-097 | 10-289-098 |
| 10 | 2-3/4 | 1 | 10-289-101 | 10-289-102 | 10-289-103 | 10-289-104 | 10-289-105 | 10-289-106 | 10-289-107 | 10-289-108 |
| 12 | 2-5/8 | 1 | 10-289-121 | 10-289-122 | 10-289-123 | 10-289-124 | 10-289-125 | 10-289-126 | 10-289-127 | 10-289-128 |
| 14 | 2-1/2 | 1 | 10-289-141 | 10-289-142 | 10-289-143 | 10-289-144 | 10-289-145 | 10-289-146 | 10-289-147 | 10-289-148 |
| 16 | 2-1/2 | 1 | 10-289-161 | 10-289-162 | 10-289-163 | 10-289-164 | 10-289-165 | 10-289-166 | 10-289-167 | 10-289-168 |
| 18 | 2-3/8 | 1 | 10-289-181 | 10-289-182 | 10-289-183 | 10-289-184 | 10-289-185 | 10-289-186 | 10-289-187 | 10-289-188 |
| 20 | 2-3/8 | 1 | 10-289-201 | 10-289-202 | 10-289-203 | 10-289-204 | 10-289-205 | 10-289-206 | 10-289-207 | 10-289-208 |
| 24 | 2-1/4 | 1 | 10-289-241 | 10-289-242 | 10-289-243 | 10-289-244 | 10-289-245 | 10-289-246 | 10-289-247 | 10-289-248 |
| 32 | 2-1/4 | 1 | 10-289-321 | 10-289-322 | 10-289-323 | 10-289-324 | 10-289-325 | 10-289-326 | 10-289-327 | 10-289-328 |
| 40 | 1-3/4 | 7/8 | 10-289-401 | 10-289-402 | 10-289-403 | 10-289-404 | 10-289-405 | 10-289-406 | 10-289-407 | 10-289-408 |
| 48 | 1-3/4 | 7/8 | 10-289-481 | 10-289-482 | 10-289-483 | 10-289-484 | 10-289-485 | 10-289-486 | 10-289-487 | 10-289-488 |
14-1/2° pressure angle module involute (metric) spur gears
Module involute gear cutters (E28)
| Module | Cutter Diameter (in.) | Hole Size (in.) | Cutter #1 | Cutter #2 | Cutter #3 | Cutter #4 | Cutter #5 | Cutter #6 | Cutter #7 | Cutter #8 |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 1 | 10-290-301 | 10-290-302 | 10-290-303 | 10-290-304 | 10-290-305 | 10-290-306 | 10-290-307 | 10-290-308 |
| 1-1/4 | 2 | 1 | 10-290-311 | 10-290-312 | 10-290-313 | 10-290-314 | 10-290-315 | 10-290-316 | 10-290-317 | 10-290-318 |
| 1-1/2 | 2 | 1 | 10-290-321 | 10-290-322 | 10-290-323 | 10-290-324 | 10-290-325 | 10-290-326 | 10-290-327 | 10-290-328 |
| 1-3/4 | 2-1/4 | 1 | 10-290-331 | 10-290-332 | 10-290-333 | 10-290-334 | 10-290-335 | 10-290-336 | 10-290-337 | 10-290-338 |
| 2 | 2-1/2 | 1 | 10-290-341 | 10-290-342 | 10-290-343 | 10-290-344 | 10-290-345 | 10-290-346 | 10-290-347 | 10-290-348 |
| 2-1/4 | 2-1/2 | 1 | 10-290-351 | 10-290-352 | 10-290-353 | 10-290-354 | 10-290-355 | 10-290-356 | 10-290-357 | 10-290-358 |
| 2-1/2 | 2-1/2 | 1 | 10-290-361 | 10-290-362 | 10-290-363 | 10-290-364 | 10-290-365 | 10-290-366 | 10-290-367 | 10-290-368 |
| 2-3/4 | 2-1/2 | 1 | 10-290-371 | 10-290-372 | 10-290-373 | 10-290-374 | 10-290-375 | 10-290-376 | 10-290-377 | 10-290-378 |
| 3 | 2-1/2 | 1 | 10-290-381 | 10-290-382 | 10-290-383 | 10-290-384 | 10-290-385 | 10-290-386 | 10-290-387 | 10-290-388 |
| 3-1/4 | 2-1/2 | 1-1/4 | 10-290-391 | 10-290-392 | 10-290-393 | 10-290-394 | 10-290-395 | 10-290-396 | 10-290-397 | 10-290-398 |
| 3-1/2 | 2-1/2 | 1-1/4 | 10-290-401 | 10-290-402 | 10-290-403 | 10-290-404 | 10-290-405 | 10-290-406 | 10-290-407 | 10-290-408 |
| 4 | 3 | 1 | 10-290-411 | 10-290-412 | 10-290-413 | 10-290-414 | 10-290-415 | 10-290-416 | 10-290-417 | 10-290-418 |
20° pressure angle module involute (metric) spur gears
Module involute gear cutters (E29)
| Module | Cutter Diameter (in.) | Hole Size (in.) | Cutter #1 | Cutter #2 | Cutter #3 | Cutter #4 | Cutter #5 | Cutter #6 | Cutter #7 | Cutter #8 |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 1 | 10-290-011 | 10-290-012 | 10-290-013 | 10-290-014 | 10-290-015 | 10-290-016 | 10-290-017 | 10-290-018 |
| 1-1/4 | 2 | 1 | 10-290-021 | 10-290-022 | 10-290-023 | 10-290-024 | 10-290-025 | 10-290-026 | 10-290-027 | 10-290-028 |
| 1-1/2 | 2-1/4 | 1 | 10-290-031 | 10-290-032 | 10-290-033 | 10-290-034 | 10-290-035 | 10-290-036 | 10-290-037 | 10-290-038 |
| 1-3/4 | 2-1/4 | 1 | 10-290-041 | 10-290-042 | 10-290-043 | 10-290-044 | 10-290-045 | 10-290-046 | 10-290-047 | 10-290-048 |
| 2 | 2-1/2 | 1 | 10-290-051 | 10-290-052 | 10-290-053 | 10-290-054 | 10-290-055 | 10-290-056 | 10-290-057 | 10-290-058 |
| 2-1/4 | 2-5/8 | 1 | 10-290-061 | 10-290-062 | 10-290-063 | 10-290-064 | 10-290-065 | 10-290-066 | 10-290-067 | 10-290-068 |
| 2-1/2 | 2-3/4 | 1 | 10-290-071 | 10-290-072 | 10-290-073 | 10-290-074 | 10-290-075 | 10-290-076 | 10-290-077 | 10-290-078 |
| 2-3/4 | 2-7/8 | 1 | 10-290-081 | 10-290-082 | 10-290-083 | 10-290-084 | 10-290-085 | 10-290-086 | 10-290-087 | 10-290-088 |
| 3 | 2-7/8 | 1 | 10-290-091 | 10-290-092 | 10-290-093 | 10-290-094 | 10-290-095 | 10-290-096 | 10-290-097 | 10-290-098 |
| 3-1/4 | 3 | 1 | 10-290-101 | 10-290-102 | 10-290-103 | 10-290-104 | 10-290-105 | 10-290-106 | 10-290-107 | 10-290-108 |
| 3-1/2 | 3 | 1 | 10-290-111 | 10-290-112 | 10-290-113 | 10-290-114 | 10-290-115 | 10-290-116 | 10-290-117 | 10-290-118 |
| 3-3/4 | 3-1/4 | 1 | 10-290-121 | 10-290-122 | 10-290-123 | 10-290-124 | 10-290-125 | 10-290-126 | 10-290-127 | 10-290-128 |
| 4 | 3-1/4 | 1 | 10-290-131 | 10-290-132 | 10-290-133 | 10-290-134 | 10-290-135 | 10-290-136 | 10-290-137 | 10-290-138 |
| 4-1/4 | 4 | 1 | 10-290-141 | 10-290-142 | 10-290-143 | 10-290-144 | 10-290-145 | 10-290-146 | 10-290-147 | 10-290-148 |
| 4-1/2 | 4 | 1 | 10-290-151 | 10-290-152 | 10-290-153 | 10-290-154 | 10-290-155 | 10-290-156 | 10-290-157 | 10-290-158 |
| 5 | 4 | 1 | 10-290-161 | 10-290-162 | 10-290-163 | 10-290-164 | 10-290-165 | 10-290-166 | 10-290-167 | 10-290-168 |
| 5-1/2 | 4 | 1 | 10-290-171 | 10-290-172 | 10-290-173 | 10-290-174 | 10-290-175 | 10-290-176 | 10-290-177 | 10-290-178 |
| 6 | 4 | 1 | 10-290-181 | 10-290-182 | 10-290-183 | 10-290-184 | 10-290-185 | 10-290-186 | 10-290-187 | 10-290-188 |
| 7 | 4-3/4 | 1-1/4 | 10-290-191 | 10-290-192 | 10-290-193 | 10-290-194 | 10-290-195 | 10-290-196 | 10-290-197 | 10-290-198 |
| 8 | 4-3/4 | 1-1/4 | 10-290-201 | 10-290-202 | 10-290-203 | 10-290-204 | 10-290-205 | 10-290-206 | 10-290-207 | 10-290-208 |
| 8-1/2 | 5-1/4 | 1-1/2 | 10-290-211 | 10-290-212 | 10-290-213 | 10-290-214 | 10-290-215 | 10-290-216 | 10-290-217 | 10-290-218 |
| 9 | 5-1/4 | 1-1/2 | 10-290-221 | 10-290-222 | 10-290-223 | 10-290-224 | 10-290-225 | 10-290-226 | 10-290-227 | 10-290-228 |
| 9-1/2 | 5-1/2 | 1-1/2 | 10-290-231 | 10-290-232 | 10-290-233 | 10-290-234 | 10-290-235 | 10-290-236 | 10-290-237 | 10-290-238 |
| 10 | 5-1/2 | 1-1/2 | 10-290-241 | 10-290-242 | 10-290-243 | 10-290-244 | 10-290-245 | 10-290-246 | 10-290-247 | 10-290-248 |
Need every chart on one free printable sheet?
Download the complete Spur Gear Cutter Selection Guide PDF: all four item charts and both cutter range tables.
Spur gear cutter basics
Diametrical pitch and module
Standard involute gears are specified by diametrical pitch. Metric gears are specified by module. Use the involute (standard) charts for diametrical pitch and the module involute (metric) charts for module.
Pressure angle
Check whether your gear has a 14-1/2° or a 20° pressure angle. These are the two pressure angles for most gears. The item charts are organized by pressure angle and by involute (standard) or module involute (metric).
How cutter numbers work
Cutter numbers #1 through #8 each cover a range of teeth. For standard involute cutters, #1 covers 135 teeth to rack and #8 covers 12 to 13 teeth. Find your cutter number from your tooth count first, then look up the item number by pitch or module.
Before you order
- Confirm your gear’s pressure angle (14-1/2° or 20°) and whether it is specified by diametrical pitch or module.
- Count the total teeth on the gear and find your cutter number (#1 through #8) in the Step 1 charts.
- Check the cutter diameter and hole size listed next to your pitch or module.
- Specify the cutter number and pitch (or module) when ordering. Items marked with an asterisk in the 14-1/2° involute chart are special sizes.
Shop the tools for the job
Frequently asked questions
What information do I need to select a spur gear cutter?
You need three things: the diametrical pitch (or module, for metric gears), the pressure angle (14-1/2° or 20° for most gears), and the total number of teeth on the gear.
How do I find my cutter number?
The cutter number comes from the number of teeth on your gear. For standard involute cutters, a gear with 17 to 20 teeth uses a #6 cutter, and a gear with 35 to 54 teeth uses a #3 cutter. Check the range chart above for your tooth count.
What is the difference between a 14-1/2° and a 20° pressure angle cutter?
The cutter must match the pressure angle of the gear you are making. Use the 14-1/2° charts for 14-1/2° gears and the 20° charts for 20° gears.
What is the difference between involute and module involute cutters?
Standard involute cutters (E18 and E188) are listed by diametrical pitch. Module involute (metric) cutters (E28 and E29) are listed by module. Use the chart that matches how your gear is specified.
Why do the metric cutters show two sets of markings?
Travers (TTC) standard markings number the module cutters in the same order as the standard involute cutters, starting with #1 for the largest tooth counts. Industry standard markings number them in the reverse order. Both are shown in the module marking guide above.
Where do I find the cutter diameter and hole size?
Both are listed in the second and third columns of each item chart, next to the diametrical pitch or module.
What do the asterisks in the chart mean?
Items marked with an asterisk in the 14-1/2° involute chart are special sizes.
What do I need to specify when ordering?
Specify the cutter number and the pitch (or module) when ordering. Each cutter number has its own Travers item number in the charts.
Who can help if I can’t find my size?
Call the Travers expert tech support team at 800.234.9985, or submit a request online. Have your diametrical pitch (or module), pressure angle and total number of teeth ready.



