One of the most used tools in model railroading is the hobby knife. Probably the most popular is the Exacto knife. While it may be the most popular, it may not be the best blade to use for your application. It all depends on WHAT you are cutting, and the TYPE of cuts you are making. Curved cuts of any kind, as well as cutting in tight places, are best done with the pointed end of an Exacto. An Exacto also has unlimited other uses. If you are making repetitive straight cuts in wood or styrene up to 1/8" thick, then a SERB (Single Edge Razor Blade) is best. The reason for this is the "included blade angle". Careful dial caliper measurements and some basic trigonometry produced the data for the following sketches, which show the angles for 4 popular blades. Clearly the SERB is thinner, and has a much more acute blade angle than the others. If you cut (or score and then snap) styrene or similar materials with an exacto blade, box cutter, or utility knife, you will wind up with a ridge on the cut edge. Using a single edge razor blade eliminates this ridge, due to the thinner blade, and a more acute angle to the cutting surface. AN ADDED BONUS IS THAT IT WILL HOLD ITS EDGE MUCH LONGER THAN AN EXACTO BLADE. Also, no ridge means that sanding can be eliminated. Blades are cheaper too (100 for about $7.00). This thread is NOT to convince anyone to use a different blade. Look at the sketches and then decide for yourself. More importantly, use what you are comfortable with. If you decide that a SERB may be better, then take a look at this thread: MYO SERB Holder
Well, that is only true when the exacto blade is new,., I resharpen mine, and they always gets steeper blade angles.
I have been working a lot in Z scale recently and there is definitely an issue with the total blade thickness of an x-acto blade and at times a razor blade would be a better choice, except, the shape does not lend itself to the close quarters of Z scale. I use them when I can. I found a cheap supply of #11 blades on the net and just bought a box of 100. Ergonomically, it is still the easiest for me to manipulate and I just change the blades regularly. I never tried sharpening my x-actos for 2 reasons, #1 I really suck at sharping any kind of blade, and #2 the blades are usually missing the point by the time I am done with it. Anyway, interesting analysis of the blade profiles. Trey
Curious now, because I seem to recall hearing a lot of pros to them a bit back, how do scalpel blades compare?
Hmmm. Interesting. All these years I had been thinking that a box cutter used what looked like a single edged razor blade.
I wonder about the same. I think perhaps some older ones did - I still have, somewhere, a scraper tool which uses SERB's.
