Blade For Triumph Scraper, carbon steel is preferred for heavy usage because it's thicker and a little stronger, but the blades generally rust quickly, so they're really only good for one day's use.
Stainless steel blades are far more resistant to rust, they are thinner and not quite as durable as carbon; if you only scrape occasionally, the stainless steel is the way to go. These carbon blades are sold in ten or 25 packs, and come in clever dispensers that safely distribute one blade at a time, and also hold used blades in a safe chamber.
Triumph Mk3 Straight Scraper has the double-edged 6-inch blade that gives you eight times the scraping width as compared to most ordinary scrapers.