# Recommended feed/speed for Extra Long Roughing bit

**URL:** <https://forum.sienci.com/t/recommended-feed-speed-for-extra-long-roughing-bit/25090>\
**Category:** 🏃🏼 Tools & Speeds\
**Created:** [December 1, 2025, 9:55pm UTC](https://forum.sienci.com/t/recommended-feed-speed-for-extra-long-roughing-bit/25090 "2025-12-01T21:55:10Z")\
**Posts on this page:** 1\
**Showing post:** 3

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**Author:** ![TDA](https://forum.sienci.com/letter_avatar_proxy/v4/letter/t/839c29/32.png) [@TDA](https://forum.sienci.com/u/TDA)\
**Post date:** [December 2, 2025, 5:39pm UTC](https://forum.sienci.com/t/recommended-feed-speed-for-extra-long-roughing-bit/25090/3 "2025-12-02T17:39:07Z")

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Usual preface, I’m with PreciseBits. So while I try to only post general information take everything I say with the understanding that I have a bias.

I went into it a couple times. Short version it get’s complicated due to the stickout of the tool (amount “sticking out” of the collet). If you want my best guesses and why:

> [@Sienci Tool Database (up to date)](https://forum.sienci.com/t/sienci-tool-database-up-to-date/12468):
>
> Hi there, I was wondering if there is some place we can download the complete Sienci endmills tool database for Fusion? I was notably trying to find a one including the 1/4″ Extra Long Flat Roughing End Mill. Thanks a lot in advance for your help.

Shorter summery:

> [@Sienci Roughing bit feed/speed](https://forum.sienci.com/t/sienci-roughing-bit-feed-speed/13912/9):
>
> Hey slovdahl. Sorry about the thread divergence. It’s partially addressed in my first reply. To summarize it, tools that stick that much out of the collet have to be run less aggressively. They are like for like more prone to deflecting (bending). The only “not like” part I can confirm on them other than the lengths is that they are a chip broken flute. That will “reduce” “some” of the deflection as you are not keeping flute engagement through the whole length (depending on crossover location a…

Hope that’s useful. Let me know if there’s something I can help with.

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