lightning bolt

https://www.youtube.com/watch?v=YCy-MutvSs8
https://www.youtube.com/watch?v=KhL4lK3uoYo
https://www.youtube.com/watch?v=8RZ10-NoV4U
https://www.youtube.com/watch?v=PpieGB80EqU
https://www.youtube.com/watch?v=vkIGuhSFP9I&list=PLXTJ8AuwrYHg3SryaHLwiGXyWB73EvU2L only a playlist i guess
https://www.youtube.com/watch?v=eaKcidunByA&list=PLz8ufS3KEgcZ33M6My_RGFD5VBzIM9JmY&index=4

running through my library rn, will update with more maybe

took way less time than i thought. might be able to find more if u want any

capitalization funny

Here are a few Metallica

https://www.youtube.com/watch?v=3i8-agWJqP0 -- From their first album, Cliff Burton on bass is legend
https://www.youtube.com/watch?v=c8qrwON1-zE -- ORION, probably their most known for instrumental
https://www.youtube.com/watch?v=TfGMinbSVI8 -- Very underrated
https://www.youtube.com/watch?v=E3Os2Z6OF60 -- My Favorite of the bunch from injustice for all, fucking beast album

They made some more in recent albums but they are just not heavy enough IMO but u could easily find them.

Roughly in order of not-math-rock to more-math-rock-than-metal,
Pelican - The Fire in Our Throats Will Beckon the Thaw: https://www.youtube.com/watch?v=k_MvDDw3nzM
Cloudkicker - The Discovery: https://www.youtube.com/watch?v=WVM603q6b1w
Animals as Leaders - The Joy of Motion: https://www.youtube.com/watch?v=gerBBFe2jPA&list=PLnuNvjXOwAEWBFVOF5ZRN2A7X1kumEG27
Sithu Aye - Pulse: https://www.youtube.com/watch?v=50bhIoSnLcA
Plini - Handmade Cities: https://www.youtube.com/watch?v=4qOeZzZh9MM
Chon - Demo EP: https://www.youtube.com/watch?v=dtFikiAEpl0

You might like Russian Circles

Look into sludge/doom. I recommend Electric Wizard, Houdini, eyehategod, acid bath and melvins. There's a /mu/ chart just for instrumental metal also https://static.wikia.nocookie.net/4chanmusic/images/0/02/Instrumental_metal.png/revision/latest?cb=20160310210914

Dark Matter Secret - Perfect World Creation
https://www.youtube.com/watch?v=-_SXebmucTc

https://www.youtube.com/watch?v=mfhRTc6SfR8
https://www.youtube.com/watch?v=juNp1dCFl-I

Widek comes to mind.

a lot of djent playlists on Spotify are instrumental, try looking there

Andrew Hulshult's soundtrack for Dusk

+1 Russian Circles

https://www.youtube.com/watch?v=N38Cv5AEziI

If typical metal vocals aren't your thing, you might like symphonic metal groups like nightwish

as for actual recs for instrumentals only, i really like demetori, a doujin music circle that makes metal instrumentals of touhou melodies:
https://www.youtube.com/watch?v=H0FRzCSnKG8
https://www.youtube.com/watch?v=G3vBO577KMs
https://www.youtube.com/watch?v=_hQq0t0EuLg

Here's some of my favourite artists:

https://www.youtube.com/watch?v=PW2aInAygfI
https://www.youtube.com/watch?v=1oiFhYl7kLM
https://www.youtube.com/watch?v=ff0T2cTuMRU

they definitely lean more towards the cleaner more mathy side of metal

https://youtu.be/vHsZTcbhOUU

https://youtu.be/rn-wj4pRpIE

sorry about the quality

https://www.youtube.com/watch?v=GOKcfyo3-xE

there's some 'vocal' at the end of this one though

Polyphia is more progressive than metal, but still really good, check them out