I've lost the screws for my battery for me Toshiba Satellite C55-B5290

Deanna M since it is a Toshiba the screws will be metric. Yes, Lowe’s has metric screws but probably not the diameter ;-). The way screws are measure on here is by length instead of measuring the actual screw size diameter. This has been my complaint for years. Anyhow, since it is a Toshiba there are not a lot of screw guides out for it. I would suggest you get a whole replacement set for your laptop. Something like this should work.

In terms of finding screws, you can usually find a close enough match with a generic laptop screw set with most consumer grade laptops like yours. Most of them are made by Clevo or Sager, so you can often get a generic screw kit and find a matched screw that’s a little shorter but fits, or a match with many of these. That said, it may be a little trickier with Toshiba/Dynabooks as they’re notoriously hard to pull service information like this out of - they have their lawyers work overtime to hide the information we need.

That isn’t as true with the business class equipment, but usually if you buy it from a manufacturer like HP who supports repair, it’s a non-issue but say if my 840 G5 needed a screw I often need to buy a screw set from HP as the business lines are different enough you often can’t buy a generic set online.