For more information on chisel hammers, see our beginner site Common Woodworking.
I have recommended these hammers as chisel and assembly hammers and i doubt that you will find finer models anywhere. I also use them for my wooden planes, to adjust and set the the irons as we do by tapping the heel, nose and iron to lighten up or deepen the cut. One thing does irritate about the hammer in its unchanged form and that it the fact the shaft tapers ever so slightly toward the end f the handle. At first this is not noticeable, but after a day or so you realize you are gripping harder than necessary because of the taper.
I reshaped my hammer shaft to a slight hollow. You must be careful not to taper too much and make the shaft diameter to small, but making this small adjustment transforms the hammer to pure joy. Two coats of boiled linseed oil and you are done.
The polypropylene head, the white one, is indestructible. It gives a very positive strike and of course the centre of percussion is as direct as can be as long as you can strike within the 38mm diameter head, which most people can. I still like my wooden mallet and nothing will replace that, but these hammers are near perfect. I have two types, one with a wooden shaft and one with a polypropylene shaft which I like equally and is a slightly heavier even though the head is the same weight.
The name of the company making them is Thor. Buying them online from Amazon is about £10. The code number for this Thor model, which is heavy enough for woodworking is 712 – 38mm. I think that is an excellent price for a lifetime hammer. You can also buy a range of screw-in replacement hammer heads that screw in to the steel head and have different hardnesses for different tasks. remember this is a panel beating hammer used for body work on cars.