Are these gloves machine washable or disposable?

Washing instructions are not specified. Rinse out oil and grease by hand after use, and let them air dry. Replace when seams start splitting or palms wear thin.

Will these fit if I wear a large in most work gloves?

Sizing details aren't confirmed in the product specs. Order conservatively and test fit one pair before committing — glove fit varies by brand and hand shape.

Do these come with any warranty or return option?

Check the site's return policy at checkout. Most work gloves can be returned within 30 days if unused — once you've got grease on them, they're yours.