# Running a 3/8" 24tpi Threading Operation **URL:** \ **Category:** Project/Part Showcase\ **Created:** [March 1, 2026, 3:53pm UTC](https://sinecorecnc.discourse.group/t/running-a-3-8-24tpi-threading-operation/17 "2026-03-01T15:53:23Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![RickJ](https://yyz1.discourse-cdn.com/flex003/user_avatar/sinecorecnc.discourse.group/rickj/32/20_2.png) [@RickJ](https://sinecorecnc.discourse.group/u/RickJ)\ **Post date:** [March 1, 2026, 3:53pm UTC](https://sinecorecnc.discourse.group/t/running-a-3-8-24tpi-threading-operation/17/1 "2026-03-01T15:53:23Z")
Here is my first part ran on the Sinecore. A 3/8”-24tpi, the cap head was drilled and broached for 5/16 hex key. I had a video to share, but it seems only photo file types are accepted. ![Cap_Screw_24tpi](https://canada1.discourse-cdn.com/flex003/uploads/sinecorecnc/original/1X/5c6b9bac773b6b0997cdd95d3515c63c98300282.jpeg) ---
**Author:** ![Aidan](https://avatars.discourse-cdn.com/v4/letter/a/c5a1d2/32.png) [@Aidan](https://sinecorecnc.discourse.group/u/Aidan)\ **Post date:** [March 3, 2026, 9:00pm UTC](https://sinecorecnc.discourse.group/t/running-a-3-8-24tpi-threading-operation/17/2 "2026-03-03T21:00:54Z")
That looks amazing! If you are able to upload the video to YouTube and link it here, I would love to see it! Did you broach with a program? ---
**Author:** ![RickJ](https://yyz1.discourse-cdn.com/flex003/user_avatar/sinecorecnc.discourse.group/rickj/32/20_2.png) [@RickJ](https://sinecorecnc.discourse.group/u/RickJ)\ **Post date:** [March 4, 2026, 12:35am UTC](https://sinecorecnc.discourse.group/t/running-a-3-8-24tpi-threading-operation/17/3 "2026-03-04T00:35:43Z")
Thanks Aidan! No, I did not broach using the program, the shank dia. was too large for the turret. I guess I could have used the tool post. Maybe next time. The broach I used was a Polygon Solutions with a 3/4” shank. I did however use the program to center drill, and drill for broaching (this video does not show that operation though). [https://youtube.com/shorts/mFW-7-dRH68](https://youtube.com/shorts/mFW-7-dRH68) ---
**Author:** ![RickJ](https://yyz1.discourse-cdn.com/flex003/user_avatar/sinecorecnc.discourse.group/rickj/32/20_2.png) [@RickJ](https://sinecorecnc.discourse.group/u/RickJ)\ **Post date:** [March 4, 2026, 1:12am UTC](https://sinecorecnc.discourse.group/t/running-a-3-8-24tpi-threading-operation/17/4 "2026-03-04T01:12:01Z")
Here is a video of the pre-drilling operations prior to the broach. The stub drill I had for this operation was a bit too big in dia., so I used a jobber drill bit I had on hand and is clearly too long, but it did the job. You will notice my feeds and speeds are pretty conservative. I’m just trying to be ‘safer than sorry’ as I get used to CNC lathe work. [https://youtube.com/shorts/g6mBNLJwxJg?feature=share](https://youtube.com/shorts/g6mBNLJwxJg?feature=share) ---
**Author:** ![RickJ](https://yyz1.discourse-cdn.com/flex003/user_avatar/sinecorecnc.discourse.group/rickj/32/20_2.png) [@RickJ](https://sinecorecnc.discourse.group/u/RickJ)\ **Post date:** [March 4, 2026, 1:19am UTC](https://sinecorecnc.discourse.group/t/running-a-3-8-24tpi-threading-operation/17/5 "2026-03-04T01:19:02Z")
5/16” Hex Key broach to cap screw. ![.3125 Hex Broach](https://canada1.discourse-cdn.com/flex003/uploads/sinecorecnc/original/1X/4ec3889e0c6bdb7f3ac3e131e6eed7e32957de33.jpeg) ---
**Author:** ![Aidan](https://avatars.discourse-cdn.com/v4/letter/a/c5a1d2/32.png) [@Aidan](https://sinecorecnc.discourse.group/u/Aidan)\ **Post date:** [March 4, 2026, 5:07pm UTC](https://sinecorecnc.discourse.group/t/running-a-3-8-24tpi-threading-operation/17/6 "2026-03-04T17:07:24Z")
Even with the warning, I was still shocked to see the length of that drill! It does look like the drill might be slightly off center, but with the conservative feed rate and the bit being able to flex a little, it clearly got the job done. Fantastic work! ---
**Author:** ![Kchu001](https://yyz1.discourse-cdn.com/flex003/user_avatar/sinecorecnc.discourse.group/kchu001/32/15_2.png) [@Kchu001](https://sinecorecnc.discourse.group/u/Kchu001)\ **Post date:** [April 7, 2026, 1:43am UTC](https://sinecorecnc.discourse.group/t/running-a-3-8-24tpi-threading-operation/17/7 "2026-04-07T01:43:55Z")
In you don’t mind, can you please share you speed and feeds specially for the parting and drilling. Thanks! ---
**Author:** ![RickJ](https://yyz1.discourse-cdn.com/flex003/user_avatar/sinecorecnc.discourse.group/rickj/32/20_2.png) [@RickJ](https://sinecorecnc.discourse.group/u/RickJ)\ **Post date:** [April 7, 2026, 11:29pm UTC](https://sinecorecnc.discourse.group/t/running-a-3-8-24tpi-threading-operation/17/8 "2026-04-07T23:29:23Z")
Here are my Fusion 360 feeds/speeds for the Center Drilling. ![Center Drill Fusion Feeds_Speeds](https://canada1.discourse-cdn.com/flex003/uploads/sinecorecnc/original/1X/cda550c75b0440a06ea3d1827654e522ad621e11.jpeg) ---
**Author:** ![RickJ](https://yyz1.discourse-cdn.com/flex003/user_avatar/sinecorecnc.discourse.group/rickj/32/20_2.png) [@RickJ](https://sinecorecnc.discourse.group/u/RickJ)\ **Post date:** [April 7, 2026, 11:30pm UTC](https://sinecorecnc.discourse.group/t/running-a-3-8-24tpi-threading-operation/17/9 "2026-04-07T23:30:55Z")
Definitely used pecking. ![Center Drill Fusion Pecking](https://canada1.discourse-cdn.com/flex003/uploads/sinecorecnc/original/1X/bcf7d16a16e4c5210bb41ec8a49cfe5791d6e2a1.jpeg) ---
**Author:** ![RickJ](https://yyz1.discourse-cdn.com/flex003/user_avatar/sinecorecnc.discourse.group/rickj/32/20_2.png) [@RickJ](https://sinecorecnc.discourse.group/u/RickJ)\ **Post date:** [April 7, 2026, 11:35pm UTC](https://sinecorecnc.discourse.group/t/running-a-3-8-24tpi-threading-operation/17/10 "2026-04-07T23:35:30Z")
Here are my Fusion 360 feeds/speeds for the Drilling. ![Drilling Fusion Feeds_Speeds](https://canada1.discourse-cdn.com/flex003/uploads/sinecorecnc/original/1X/a8e88623974ac77ff3d6a22418fd9917a3bed6ff.jpeg) ---
**Author:** ![RickJ](https://yyz1.discourse-cdn.com/flex003/user_avatar/sinecorecnc.discourse.group/rickj/32/20_2.png) [@RickJ](https://sinecorecnc.discourse.group/u/RickJ)\ **Post date:** [April 7, 2026, 11:36pm UTC](https://sinecorecnc.discourse.group/t/running-a-3-8-24tpi-threading-operation/17/11 "2026-04-07T23:36:43Z")
Again pecking is important. ![Drilling Fusion Pecking](https://canada1.discourse-cdn.com/flex003/uploads/sinecorecnc/original/1X/d944203adb7864614c828f327daba887d4b71d20.jpeg) ---
**Author:** ![RickJ](https://yyz1.discourse-cdn.com/flex003/user_avatar/sinecorecnc.discourse.group/rickj/32/20_2.png) [@RickJ](https://sinecorecnc.discourse.group/u/RickJ)\ **Post date:** [April 7, 2026, 11:40pm UTC](https://sinecorecnc.discourse.group/t/running-a-3-8-24tpi-threading-operation/17/12 "2026-04-07T23:40:53Z")
Here are my Fusion 360 feeds/speeds for the final Parting. ![Parting Fusion Feeds_Speeds](https://canada1.discourse-cdn.com/flex003/uploads/sinecorecnc/original/1X/79a165449456c90de5c7f28da6298efb1a8afd46.jpeg) ---
**Author:** ![RickJ](https://yyz1.discourse-cdn.com/flex003/user_avatar/sinecorecnc.discourse.group/rickj/32/20_2.png) [@RickJ](https://sinecorecnc.discourse.group/u/RickJ)\ **Post date:** [April 7, 2026, 11:44pm UTC](https://sinecorecnc.discourse.group/t/running-a-3-8-24tpi-threading-operation/17/13 "2026-04-07T23:44:53Z")
Again the pecking for the parting seemed to work great for me, although not sure it is necessary. There are of course many other setting for these operations but these to me seem to be the most important to share. I hope this helps, and good Luck! ![Parting Fusion Pecking](https://canada1.discourse-cdn.com/flex003/uploads/sinecorecnc/original/1X/507ea831870ec40b14f292a0a9bb35a2899eb088.jpeg) ---
**Author:** ![Kchu001](https://yyz1.discourse-cdn.com/flex003/user_avatar/sinecorecnc.discourse.group/kchu001/32/15_2.png) [@Kchu001](https://sinecorecnc.discourse.group/u/Kchu001)\ **Post date:** [April 19, 2026, 7:52pm UTC](https://sinecorecnc.discourse.group/t/running-a-3-8-24tpi-threading-operation/17/14 "2026-04-19T19:52:41Z")
@RickJ I really appreciate you sharing this information!