my mechanics insights's video: Making a Knurling Tool for the Lathe Narrated

In this video i'm making a knurling tool for the lathe. I needed to make a straight knurling for my „combination lock“ video on my main channel. I did use my friends knurling tool in a previous video, as it's good to have your own I decide to make one. I bought two straight knurling wheels and now I only need to make a holder for them to use it on the lathe. The first thing I did was making a drawing of it with all the measurements and tolerances. Once I knew the dimensions of the finished part I could organize the material. As material I choose a heat treatable steel 36CrNiMo6 (1.6582). The good thing about this steel is you can't overheat it when hardening and ruin the hardening, as I'm just going to harden it with a blowtorch that's perfect. The piece was much bigger in the beginning than it actually needed to be, but that's no problem I'll just take a few cuts more and make some more chips. I got this part for free from my friend, so I was happy to get started. First, I turn the part to lenght on the lathe (120mm). Next I did mill it to it's dimension 20x25mm, once I had this done I took out the step 5x95mm. Then I milled the slot for the knurling wheel. Once I got that I only needed to make the hole for the pin and cut the thread which will hold the pin. After the machining I did the heat treatment. Heat it up to around 800°C (cherry), hold the temperature for a moment and quench the part in oil. After that I needed to temper it to take a bit of it's hardness and stress away. Because of the high temperatur of the quench the part turns black, but it won't stick properly and start to peel of. So I cleaned it all up with Scotch Brite and then I used the bluing liquid to give it a nice and even black finish. The final test worked very well. By the way, I didn't clamp the knurling tool 90° to the part, I clamped it at 91°. This way only the right edge of the wheel will cut to the final diameter, which gives it a much nicer finish. I hope you like my work and the video. Huge thank you to all of my Patreon and PayPal supporters and specially to: Afreeflyingsoul Stewen Guyot Adel AlSaffar Alan Hanson Amanda Taylor, Esq Andreswara Hermawan Andrew Phillips Dan Williams Gregory Joan Casanovas John Romero Jonas Richartz LVE Marc P Paul Ambry Paul Mampilly TallBaldandCrafty Trevor Kam Vince Valenti Zachary Grimes Timestamps: 00:00 intro 00:08 showing the knurling wheels 00:18 showing the drawing with the measurements 00:26 showing the starting material (36crNiMo6) 00:46 turning the part to lenght on the lathe 01:30 making the part 20x25 on the mill 03:01 making the step 5x95mm on the mill 03:51 turning the mill head 45° and mill the big angles 04:26 milling the slot for the knurling wheel 05:13 drilling and reaming the hole for the pin 05:58 drilling and threading for the threaded pin 06:30 removing all sharp edges 07:16 preparing the hardened pin 07:52 test assembly before hardening 08:16 hardening and tempering 08:51 bluing with bluing liquid 09:19 assembling 09:33 final test 10:56 footage of the „combination lock“ video 11:20 showing the finished knurling tool Time and costs of this project: I was working on this project for 1 day $80 two knurling wheels I turn a Stainless Bolt into a Combination Lock: https://www.youtube.com/watch?v=OyhfQYHnJuM My main channel: https://www.youtube.com/channel/UCMrMVIBtqFW6O0-MWq26gqw? My camera: Panasonic HC-V180 If you have any questions about the process, machines i'm using or other stuff, just ask me in the comments. I read them all and i try to reply as soon as possible. Sorry for my bad english, it's not my language. I try my best to improve my technical english. Subscribe for more of my content. I'm uploading videos about mechanical stuff, mostly bonus material from projects on my main channel. Thank you for watching :-) My Patreon Page: https://www.patreon.com/mymechanics My PayPal: my_mechanics@hotmail.com Follow me on Instagram: https://www.instagram.com/my_mechanics/