Every skilled woodworker knows the importance of a high quality, well-tuned chisel. Fine hand work requires a very sharp chisel, and we spend a lot of time honing chisels to get an edge sharp enough to shave hair. So what qualities should you look for when buying your first set of good chisels?
#1 is quality of the tool steel. Quality of steel equates to how long the cutting edge will hold out as it cuts through dense wood. Since there is no way to test the alloy content of a tool or how it was tempered, we can only go by the hardness rating and the reputation of the manufacturer, which can change over time. The most common scale used for hardness is Rockwell C, and good chisels are usually in the Rc 58 to 62 range. Those chisels that you can buy at the big box hardware store are a much softer steel because most people will use them in situations where they can run into a nail and other non-wood materials. The softer steel won’t chip and break so easily, it will bend and deform first. Unfortunately, that softer steel that can bend will also not be able to hold a really sharp edge, it will roll right over in anything harder than soft pine. Manufacturers can change their sources and methods as well. I bought my chisels about 35 years ago from Marples, which was a good quality brand made in England using “Sheffield steel”. They also have other great qualities that I’ll mention later. Later on, the Marples brand was bought by Irwin, and the quality of the steel went way down. In the last 7 years, Irwin has made an effort to improve the steel somewhat but it is not like the old stuff. Best quality steel that I’ve seen recently is from Ashley iles and Two Cherries.
#2 is the shape of the bevels and the edges on the sides of the chisel. All chisels except mortising chisels have a bevel running down the length of each side. The bevel does not come all the way down to the back of the chisel, so there is a 90 degree flat edge along the sides of the chisel. I have seen that edge be as wide as 1/8”. Ashley iles American pattern chisels come to only 1/32’ at the tip of the chisel. This smaller edge is useful for cutting dovetails because the cutting corner of the chisel can fit into the acute angle of the dovetail cut-out. The Two Cherries chisels are nice steel, but the edges are pretty wide. I have known people to buy Two Cherries and then grind the bevels down to get a great chisel. They do this because it is hard to find firmer chisels anymore, most manufacturers are making butt chisels. What are those terms you ask?
#3 is the length of the chisel blade. Firmer chisels are long, and butt chisels are short. Both can be struck with a mallet because the blade is fairly thick, and both are usually sharpened at an angle of 25 to 27 degrees. Both work well for cutting dovetails, and firmer chisels will withstand more sharpenings, but mainly it is easier to sight down the length of the firmer chisel blade when eyeing the angle of the blade as it enters the wood. There are also paring chisels which are typically long and thin and sharpened to a lower angle of about 20 degrees. They are not designed to be struck with a mallet, rather they are made for taking very thin shavings off with just the pressure of the hand.
#4 is the shape of the handle. Some handles have a cylindrical shape with a ferrule (a metal ring) around the end which keeps the wooden handle from splitting but are not very comfortable to hold in the hand. Some have an oval shaped profile which makes it easy to tell where the flat of the blade is just by feel, and they fit the shape of the hand better.
#5 is cost. we would all love to buy the most expensive, beautiful chisels but that is not possible for many people, especially when you are first starting out and are not even sure that woodworking is the thing for you. It will be necessary to spend a good amount of time sharpening your chisels so it doesn’t make a lot of sense to invest all of that time on a set of cheap chisels that won’t hold an edge. However, there have been numerous articles published comparing chisels and their cost-to-quality ratio. Narex are the least expensive but a little bit more money brings a much better tool called Wood River sold by woodcraft. If I had to buy a new set of chisels it would be hands down the Ashley iles firmer chisels.
Next blog entry will be on sharpening chisels. ALL chisels have to be sharpened, no matter how nice they look straight out of the box.