Both of those should function. You'll probably really need to sharpen additional commonly with HSS. But, I built a few dozen blanks for bezels out of 40mm bar, turning do the job was with carbide, but used HSS for parting off, and bought all twelve parted without the need of https://richard-mille84826.answerblogs.com/35099375/the-basic-principles-of-錶鋪