Fitting a Scraper
Scrapers should be fitted to the person doing the scraping. Just as a precision marksman has the stock of his rifle made to fit, so must a scraper hand have a scraper the right size to suit his stature and personal scraping style. A taller man has longer arms and to hold the scraper comfortably in the proper stance for long periods, it follows that he must have a longer scraper. A shorter man would require a scraper that is shortened for the same reason.
A general guide for sizing scrapers to operators
5' 5" and shorter = 18" or shorter
5' 9" to 6' 2" = 18" to 20"
6' 2" and up = 20" or more
Even with these guidelines, it is important to remember that each person will have their own preferences about scraper size so do not be locked in to this guide as an unbreakable rule. I know scraper hands that are very tall and use the shorter scrapers quite well. Remember though, when buying or building a scraper that it is easier to cut a scraper to make it shorter than it is to stretch it to make it longer.

Files as Scrapers
It is sometimes said that the easiest way to make a scraper is to grind the proper blade shape onto the end of an old file. There are a great many problems that come from building a scraper in this way.
Files are normally only case hardened. This gives them the flexibility needed to be used without breaking as a through -hardened piece would. This hardened depth usually goes only as deep as the teeth of the file. These teeth must be removed from the end of the file or a smooth finish is unobtainable when scraping with this type of tool. After these teeth are removed, the remaining material is usually not suitable for holding an edge. Having to continually sharpen a scraper can very quickly turn a simple job into a major chore.
Files large enough to grasp as a scraper are thicker than scraper blades. This extra thickness can cause scraping the inside of dovetails to be extremely difficult and in some cases impossible.
A truly effective tool is one that is made for the job it will perform. Because of the fine quality work scrapers are used for, this is true of the hand scraper more than most other tools. After all, it is possible to disassemble the engine in your car with little more than a hammer, a screwdriver, and a pair of vise grips, but would you want to?

Choosing a Blade Type
Determining which blade material to use depends on how and where you will be scraping.
The main advantage of carbide over HSS, is that it stays sharp longer, in some applications up to ten times longer. This means less time spent sharpening the blade and more time using it. The initial cost of the blade is higher, but this is more than overcome by the timesavings carbide offers. The main disadvantage of carbide is the requirement of a carbide tool grinder equipped with a quality diamond wheel for sharpening. Portable grinders do exist because carbide is nearly impossible to properly sharpen by hand, even with a diamond bench stone. Carbide also has a reputation for leaving a scratched finish, but this may be eliminated with proper selection and use of the grinding wheel used for sharpening.
The main advantage of HSS is the ease of maintenance. High-speed steel can be sharpened by hand to a very keen edge with a common bench stone. This makes the HSS blade much more portable than the carbide blade. When scraping "on the road" or in a shop without a carbide tool grinder, high-speed steel may be the only choice. The initial cost of the blades is also lower. The main disadvantage to the HSS blade is that it does not hold an edge as long as carbide. In some tough materials, this can make a HSS blade difficult to use because the blade may need to be sharpened almost continuously.

Blade Material In the past, the only blade material was tool steel or high-speed steel. Just as high-speed steel (HSS) has largely been replaced by carbide in the machining world, carbide has also become a popular scraper blade material. High-speed steel is still popular, because for a scraper hand it can offer some advantages over carbide. Today both carbide and high-speed steel (HSS) are used as blade materials.